{"gene":"MRTFA","run_date":"2026-06-10T02:59:51","timeline":{"discoveries":[{"year":2002,"finding":"BSAC/MKL1 is a nuclear transcriptional activator that potently activates promoters containing CArG boxes (A+T-rich sequences). Both N-terminal basic and C-terminal proline-rich domains are required for transcriptional activity. Overexpression inhibits TNF-induced caspase activation and cell death, with an intimate correlation between transcriptional activity and antiapoptotic function.","method":"Functional cloning, reporter gene assay, domain deletion mutagenesis, overexpression in DKO MEFs","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional cloning with domain mapping and reporter assays in a single lab","pmids":["12019265"],"is_preprint":false},{"year":2004,"finding":"MKL1 functions as a Rho GTPase-regulated coactivator of SRF to drive a subset (~28 of 150) of serum-inducible immediate-early genes; dominant-negative MKL1 specifically blocks the Rho-MKL pathway without affecting TCF/Elk1-dependent SRF targets.","method":"Microarray expression profiling using dominant-negative MKL1 cell line, promoter analysis","journal":"BMC molecular biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genome-wide functional screen with DN-MKL1, single lab","pmids":["15329155"],"is_preprint":false},{"year":2005,"finding":"MKL1 is covalently modified by SUMO-1 at lysine residues K499, K576, and K624. SUMOylation is enhanced by serum stimulation or constitutively active RhoA. Mutation of these three sites strongly enhances MKL1 transcriptional activity without affecting MKL1-SRF interaction, demonstrating that SUMOylation represses MKL1 transcriptional activity.","method":"Yeast two-hybrid (identified UBC9), GST pull-down, in vitro SUMOylation reconstitution, site-directed mutagenesis, reporter gene assay","journal":"Genes to cells : devoted to molecular & cellular mechanisms","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution of SUMOylation plus mutagenesis of acceptor sites with functional readout, single lab with multiple orthogonal methods","pmids":["16098147"],"is_preprint":false},{"year":2006,"finding":"MKL1/Mkl1 is required for physiological preparation of the mammary gland during pregnancy and maintenance of lactation. Mkl1 knockout mice exhibit premature involution and impaired expression of SRF-dependent genes in mammary myoepithelial cells, establishing MKL1 as an essential SRF coactivator in this tissue.","method":"Gene targeting (Mkl1 knockout mice), histology, gene expression analysis","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean knockout model with specific tissue phenotype and molecular readout","pmids":["16847333"],"is_preprint":false},{"year":2006,"finding":"MKL1 and MKL2 regulate expression of CArG-containing smooth muscle marker genes (SM alpha-actin, telokin) but not CArG-independent genes. PDGF-BB causes dissociation of MKL factors from CArG-containing promoters via competition with phospho-Elk-1 and subsequent HDAC2/4/5-mediated reduction of acetylated histone H4, repressing SMC marker genes.","method":"Gain- and loss-of-function experiments, chromatin immunoprecipitation (ChIP)","journal":"American journal of physiology. Cell physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP plus functional assays in a single lab","pmids":["16987998"],"is_preprint":false},{"year":2008,"finding":"MKL1 directly activates alpha-smooth muscle actin (alpha-SMA) transcription via CArG elements in renal tubular epithelial cells. MKL1 fused to GFP localizes to the nucleus and induces alpha-SMA expression regardless of TGF-β1. siRNA knockdown of MKL1 abolishes TGF-β1-stimulated alpha-SMA expression. ChIP demonstrates that TGF-β1 induces binding of endogenous SRF and MKL1 to the alpha-SMA promoter. MKL1 expression is regulated by the proteasomal ubiquitin pathway.","method":"GFP fusion localization, siRNA knockdown, ChIP, reporter gene assay, proteasome inhibitor treatment","journal":"American journal of physiology. Renal physiology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (ChIP, siRNA, localization, reporter), single lab","pmids":["18337547"],"is_preprint":false},{"year":2008,"finding":"The oncogenic OTT-BSAC/MKL1 fusion protein localizes exclusively to the nucleus (unlike BSAC alone which is predominantly cytoplasmic), aberrantly activates promoters containing YY1-binding sequences, and its formation disrupts the interaction between OTT and HDAC3, collectively perturbing normal transcriptional regulation.","method":"Subcellular localization assay, reporter gene assay, co-immunoprecipitation","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal protein interaction assays plus localization and functional readout, single lab","pmids":["18667423"],"is_preprint":false},{"year":2009,"finding":"MKL1 promotes megakaryocytic differentiation by activating SRF. Overexpression of MKL1 increases megakaryocyte number and ploidy; this effect is abrogated by SRF knockdown. Mkl1 knockout mice have reduced platelet counts and reduced megakaryocyte ploidy.","method":"MKL1 overexpression in HEL cells and primary CD34+ cells, SRF knockdown, Mkl1 knockout mice","journal":"Blood","confidence":"High","confidence_rationale":"Tier 2 / Strong — epistasis (SRF knockdown abolishes MKL1 effect) plus in vivo knockout, replicated across cell types","pmids":["19136660"],"is_preprint":false},{"year":2010,"finding":"MKL/MRTF family members are found tethered to monomeric actin in the cytoplasm of hippocampal neurons but translocate to the nucleus upon synaptic activation, where they associate with SRF to regulate expression of structural genes. Mkl expression undergoes learning-associated changes in the hippocampus, contributing to two phases of gene regulation during memory consolidation.","method":"Subcellular localization by immunofluorescence, passive avoidance conditioning, gene expression analysis","journal":"Cerebral cortex (New York, N.Y. : 1991)","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — localization and expression studies linked to a behavioral readout, single lab","pmids":["20016002"],"is_preprint":false},{"year":2010,"finding":"Activin promotes dendritic complexity of cortical neurons in an SRF- and MKL-dependent manner. Activin promotes nuclear export of SCAI (a corepressor of SRF-MKL), and SCAI overexpression blocks activin-induced SRF transcriptional responses and dendritic complexity, identifying an activin-SCAI-MKL signaling axis.","method":"Neuronal morphology analysis, SCAI overexpression/knockdown, SRF reporter assay, subcellular localization of SCAI","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — epistasis via SCAI manipulation, multiple readouts, single lab","pmids":["20709749"],"is_preprint":false},{"year":2012,"finding":"MKL1 and MKL2 play redundant roles in megakaryocyte maturation and platelet formation: double-knockout (MKL1/MKL2) megakaryocytes show more severe thrombocytopenia, ploidy reduction, and cytoskeletal/membrane disorganization than single MKL1 KO. Comparison of gene expression in DKO vs. SRF-deficient megakaryocytes reveals ~4400 differentially regulated genes, indicating both SRF-dependent and SRF-independent activities.","method":"Conditional Mkl2 knockout on Mkl1 KO background (DKO), platelet counting, electron microscopy, immunofluorescence, gene expression comparison with SRF KO","journal":"Blood","confidence":"High","confidence_rationale":"Tier 2 / Strong — double knockout mouse model, multiple orthogonal phenotypic assays, genetic epistasis with SRF KO","pmids":["22806889"],"is_preprint":false},{"year":2012,"finding":"MRTF-A/MAL promotes expression of adhesive genes (integrin α5, plakophilin 2/Pkp2, FHL1) via the actin-MAL-SRF signaling pathway. Elevated MAL impairs migration of non-invasive cells; knockdown of integrin α5, Pkp2, or FHL1 reverses this anti-migratory effect. ChIP shows inducible MAL/SRF recruitment to regulatory elements of the integrin α5 and Pkp2 genes.","method":"MAL overexpression and dominant-negative constructs, siRNA knockdown, wound-healing assay, ChIP","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Moderate — ChIP demonstrating direct promoter occupancy, multiple functional rescue experiments, single lab","pmids":["22223881"],"is_preprint":false},{"year":2012,"finding":"MRTF-A expression is induced in injured/dedifferentiated vascular smooth muscle cells (VSMCs) and drives pathological vascular remodeling. MRTF-A promotes VSMC migration by activating SRF targets vinculin, MMP-9, and integrin β1. MRTF-A induction in dedifferentiated VSMCs is caused by downregulation of microRNA-1.","method":"MRTF-A knockout mice (wire injury and ApoE-/- atherosclerosis models), siRNA knockdown in VSMCs, migration assays, CCG1423 pharmacological inhibition","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple in vivo knockout models with specific molecular targets identified, replicated across two disease models","pmids":["23103763"],"is_preprint":false},{"year":2013,"finding":"Lamin A/C-deficient and Lmna(N195K/N195K) mutant cells have impaired nuclear translocation of MKL1 caused by altered actin dynamics. Ectopic expression of emerin, which is mislocalized in Lmna mutant cells, restores MKL1 nuclear translocation and rescues actin dynamics. This establishes that lamin A/C and emerin regulate MKL1 nucleo-cytoplasmic shuttling through modulation of actin polymerization.","method":"Live-cell imaging of MKL1 translocation, ectopic emerin expression in Lmna-/- cells, actin dynamics assays","journal":"Nature","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean KO models, rescue experiments, live imaging, two orthogonal genetic interventions","pmids":["23644458"],"is_preprint":false},{"year":2013,"finding":"MKL1 is recruited to the ET-1 promoter by SRF in response to hypoxia in human vascular endothelial cells, where it facilitates histone modifications consistent with transcriptional activation and recruits chromatin remodeling complex components Brg1 and Brm, which are indispensable for ET-1 transactivation.","method":"ChIP, dominant-negative MKL1, siRNA knockdown, reporter assay","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 2 / Moderate — ChIP demonstrating direct promoter occupancy plus functional rescue with multiple components, single lab","pmids":["23625963"],"is_preprint":false},{"year":2013,"finding":"MRTF-A promotes SMYD3-dependent histone methylation on the MYL9 promoter to activate MYL9 transcription and breast cancer cell migration. Co-immunoprecipitation and mutation analysis show that this cooperative transactivation requires the proximal CArG-box binding element of MRTF-A and the HMT activity of SMYD3.","method":"Co-IP, siRNA knockdown, reporter gene assay with promoter mutation, cell migration assay, ChIP","journal":"Cancer letters","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus functional mutagenesis, single lab","pmids":["24189459"],"is_preprint":false},{"year":2013,"finding":"Cell shape regulates MRTF-A subcellular localization during TGF-β1-induced EMT: cell spreading promotes nuclear accumulation of MRTF-A, whereas blocking cell spreading prevents MRTF-A nuclear translocation and the myofibroblast phenotype. Overexpression of MRTF-A promotes cytoskeletal protein expression independent of cell shape.","method":"Micro-contact printing to control cell shape, pharmacological inhibition of cytoskeletal tension (blebbistatin), MRTF-A overexpression, immunofluorescence","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — localization assay with functional consequence linked to shape, single lab with multiple inhibitors","pmids":["24340092"],"is_preprint":false},{"year":2014,"finding":"Induction of adipocyte differentiation disrupts actin stress fibres via RhoA-ROCK downregulation, causing a rapid increase in monomeric G-actin that binds MKL1 and prevents its nuclear translocation, thereby allowing PPARγ expression and adipogenic differentiation. MKL1 and PPARγ act in a mutually antagonistic manner during adipogenic differentiation.","method":"Actin manipulation (cytochalasin D, latrunculin A), MKL1 overexpression/siRNA, PPARγ reporter assay, Co-IP, subcellular fractionation","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal biochemical and genetic approaches, mechanistic model with G-actin binding established, single lab","pmids":["24569594"],"is_preprint":false},{"year":2014,"finding":"Thymosin β4 (Tβ4) induces MRTF-A translocation to the nucleus by binding G-actin, activating SRF and driving CCN1 and CCN2 transcription to promote capillary proliferation and pericyte recruitment, respectively. Loss of MRTF-A/B or CCN1 function abolishes the Tβ4 neovascularization effect.","method":"Forced MRTF-A expression, MRTF-A/B knockout mice, hindlimb ischemia model, functional assays, nuclear translocation imaging","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis in knockout mice plus overexpression, multiple in vivo models across species, replicated","pmids":["24910328"],"is_preprint":false},{"year":2014,"finding":"MRTF-A is recruited to the ET-1 promoter by c-Jun/c-Fos (AP-1) in response to Ang II, where it alters chromatin structure by modulating histone acetylation and H3K4 methylation, driving ET-1 transcription and cardiac hypertrophy. Endothelial-specific MRTF-A silencing phenocopies systemic MRTF-A deletion in Ang II-induced pathological hypertrophy.","method":"ChIP, MRTF-A overexpression/depletion, lentiviral endothelial-specific silencing, luciferase reporter, co-IP","journal":"Journal of molecular and cellular cardiology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — ChIP plus cell-specific in vivo genetic intervention plus multiple biochemical assays, single lab","pmids":["25446178"],"is_preprint":false},{"year":2014,"finding":"MRTF-A and STAT3 physically interact and synergistically activate transcription of migration markers MYL9 and Cyr-61 via CArG box binding, promoting breast cancer cell migration. The RhoA-MRTF-A and JAK-STAT3 pathways cross-talk in this process.","method":"Co-IP demonstrating physical MRTF-A/STAT3 interaction, reporter assay, siRNA knockdown, migration assay","journal":"Cellular signalling","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — Co-IP plus reporter assay with functional migration readout, single lab","pmids":["25038455"],"is_preprint":false},{"year":2015,"finding":"Loss-of-function homozygous MKL1 mutation in a human patient causes primary immunodeficiency characterized by loss of F-actin content in immune cells, reduced G-actin levels, and downregulation of multiple actin-regulating genes. MKL1-deficient neutrophils display severely impaired migration and nearly abolished phagocytosis, and primary dendritic cells cannot form podosomes. Myeloid cell silencing experiments confirm that F-actin assembly is abrogated through reduced G-actin levels.","method":"Patient genetic analysis, flow cytometry (F-actin content), migration assays, phagocytosis assay, siRNA knockdown in myeloid cell lines","journal":"Blood","confidence":"High","confidence_rationale":"Tier 2 / Strong — human loss-of-function genetics confirmed by cellular reconstitution experiments across multiple cell types","pmids":["26224645"],"is_preprint":false},{"year":2015,"finding":"MKL1 promotes lung cancer cell migration and invasion by epigenetically activating MMP9 transcription. MKL1 recruits ASH2 (a component of the H3K4 methyltransferase complex) to the MMP9 promoter, and MKL1 knockdown eliminates H3K4 methylation at the MMP9 promoter.","method":"ChIP, siRNA knockdown, migration/invasion assays, reporter assay","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP showing promoter recruitment and histone modification, functional migration readout, single lab","pmids":["25746000"],"is_preprint":false},{"year":2015,"finding":"TGF-β induces MKL1 binding to pro-fibrogenic gene promoters. MKL1 promotes the interaction between MKL1 and SMAD3 — each requiring the other for chromatin occupancy. MKL1 recruits a H3K4 methyltransferase complex to fibrogenic promoters, and knockdown of individual complex members reduces SMAD3 binding and portal fibroblast activation.","method":"ChIP, Co-IP, siRNA knockdown, bile duct ligation mouse model","journal":"Biochimica et biophysica acta","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP plus Co-IP with in vivo model, single lab","pmids":["26241940"],"is_preprint":false},{"year":2015,"finding":"Filamin A (FLNA) physically interacts with MKL1 via identified interaction domains. FLNA-MKL1 interaction is required for MKL1 target gene expression and cell migration in primary fibroblasts and cancer cells. LPA-induced RhoA activation promotes endogenous MKL1-FLNA association; actin polymerization inhibitors dissociate the complex. An MKL1 mutant unable to bind FLNA shows impaired cell migration and reduced SRF target gene expression, establishing FLNA as a positive transducer linking F-actin to MKL1-SRF activity.","method":"Co-IP, domain mapping, site-directed mutagenesis, reporter assay, migration assay across multiple cell types","journal":"Science signaling","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, domain mapping, mutagenesis, and functional migration assay across multiple cell types in single study","pmids":["26554816"],"is_preprint":false},{"year":2015,"finding":"Mkl1 SAP domain-dependent signaling (independent of SRF) mediates aggressive mammary tumor progression following radiotherapy. Application of dynamic strain or matrix stiffness converts predominantly SRF/Mkl1-dependent gene expression to SAP-domain-dependent Mkl1 signaling and promotes SAP-dependent tumor cell migration; tumors expressing Mkl1 lacking the SAP domain exhibit impaired growth and metastasis.","method":"Tumor overexpression (full-length vs. SAP-deleted Mkl1), in vivo preirradiated mammary gland model, migration assays, transcript profiling","journal":"Molecular oncology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — domain deletion in vivo model with transcriptomic and functional readouts, single lab","pmids":["25999144"],"is_preprint":false},{"year":2015,"finding":"MKL1 inhibits cell cycle progression in podocytes via transcriptional activation of p21 through a CArG element in the p21 promoter. MKL1 overexpression decreases S-phase cells; knockdown has the opposite effect. ChIP confirms MKL1 recruitment to the p21 promoter.","method":"MKL1 overexpression and siRNA knockdown, cell cycle analysis (flow cytometry), ChIP, PCR array, reporter assay","journal":"BMC molecular biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP plus gain/loss of function with cell cycle readout, single lab","pmids":["25888165"],"is_preprint":false},{"year":2016,"finding":"Rho-dependent MRTF-A phosphorylation reflects relief from inhibitory nuclear actin. Multiple serum-induced S/T-P phosphorylation sites are required for transcriptional activation. ERK-mediated S98 phosphorylation inhibits G-actin complex assembly on the RPEL domain, promoting nuclear import. S33 phosphorylation potentiates an autonomous Crm1-dependent N-terminal NES that cooperates with five other NES elements to exclude MRTF-A from the nucleus. Thus phosphorylation plays both positive and negative roles in MRTF-A regulation.","method":"Phosphosite mapping (mass spectrometry), site-directed mutagenesis, nuclear localization assays, Crm1 inhibition, in vitro G-actin binding assay","journal":"eLife","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro biochemistry, site-directed mutagenesis at multiple sites, nuclear localization assays, mass spectrometry-based mapping in a single comprehensive study","pmids":["27304076"],"is_preprint":false},{"year":2016,"finding":"MRTF-A and STAT3 synergistically recruit DNMT1 to the BRMS1 promoter, causing hypermethylation and transcriptional silencing of BRMS1 to promote breast cancer cell migration. Physical interaction between MRTF-A and STAT3 promotes DNMT1 transactivity by binding to the GAS element in the DNMT1 promoter.","method":"Luciferase reporter assay, Co-IP, ChIP, bisulfite sequencing, siRNA knockdown, migration assay","journal":"IUBMB life","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus ChIP plus methylation assay, single lab","pmids":["25854163"],"is_preprint":false},{"year":2016,"finding":"MKL regulates cellular levels of profilin isoforms Pfn1 and Pfn2 indirectly through modulation of STAT1, utilizing MKL's SAP domain function independently of SRF. MKL also influences Pfn1 cellular externalization rather than transcription, and modulates cell migration through Pfn1.","method":"Reporter assay, siRNA knockdown, MKL SAP domain mutants, migration assay, cellular fractionation","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple assays including domain mutants, single lab","pmids":["28546428"],"is_preprint":false},{"year":2016,"finding":"p38MAPK/MK2 phosphorylates MRTF-A at Ser351 (Ser312 in human) and Ser371 (Ser333 in human) in a stress-dependent (not mitogen-induced) manner. This was confirmed by in vitro kinase assay, phospho-specific antibodies, MK2/3-deficient cells, and phospho-site mutants. However, these phosphorylations do not detectably affect MRTF-A dimerization, subcellular localization, actin interaction, SRF interaction, SMAD3 interaction, or transactivating potential under the tested conditions.","method":"Phosphoproteomic approaches (two independent), in vitro kinase assay, phospho-site mutagenesis, subcellular localization assay, MK2/3 KO cells","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — in vitro kinase assay plus mutagenesis, but functional consequences are negative/undetermined","pmids":["27492266"],"is_preprint":false},{"year":2016,"finding":"MKL1 independently inhibits brown adipogenesis. MKL1 knockdown induces brown adipocyte differentiation and increases PPARγ target gene expression. Co-IP demonstrates that MKL1 physically interacts with PPARγ, suggesting MKL1 exerts its effect by modulating PPARγ activity independently of its SRF-related function.","method":"siRNA knockdown, brown adipocyte differentiation assays, Co-IP, UCP1 and thermogenic gene expression","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — Co-IP plus functional differentiation assay, single lab","pmids":["28125644"],"is_preprint":false},{"year":2017,"finding":"MKL1 is acetylated in vivo by PCAF (lysine acetyltransferase). Pro-inflammatory stimuli (TNF-α, LPS) augment MKL1 acetylation and promote MKL1 binding to NF-κB target promoters. Acetylation at four conserved lysine residues is required for MKL1 trans-activation of NF-κB target genes. Mechanistically, MKL1 acetylation promotes nuclear enrichment, enhances MKL1-NF-κB interaction, and stabilizes MKL1 binding to target promoters.","method":"Co-IP (MKL1-PCAF interaction), acetylation assay, site-directed mutagenesis (4 Lys mutant), ChIP, nuclear fractionation, reporter assay","journal":"Biochimica et biophysica acta. Gene regulatory mechanisms","confidence":"High","confidence_rationale":"Tier 2 / Moderate — writer identified (PCAF), mutagenesis of acceptor sites, ChIP for promoter occupancy, multiple orthogonal methods, single lab","pmids":["28571745"],"is_preprint":false},{"year":2017,"finding":"MKL1 recruits SET1 (H3K4 methyltransferase) and BRG1 (chromatin remodeler) to the MMP2 promoter via NF-κB in response to hypoxia in ovarian cancer cells, coordinating their interaction to alter chromatin structure and activate MMP2 transcription. This promotes cancer cell migration and invasion.","method":"ChIP, Co-IP, siRNA knockdown, reporter assay, migration/invasion assay","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP plus Co-IP plus functional assay, single lab","pmids":["28385531"],"is_preprint":false},{"year":2017,"finding":"WDR1 promotes nuclear import of MRTF-A by affecting expression of the nuclear transport protein importin, enhancing MRTF-A-induced cell migration. MRTF-A in turn promotes miR-206 expression via CArG box in its promoter; miR-206 then inhibits WDR1 and MRTF-A expression, forming a feedback loop regulating breast cancer cell migration.","method":"siRNA knockdown, nuclear fractionation, importin expression analysis, reporter assay (CArG box), migration assay","journal":"Experimental cell research","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — nuclear fractionation plus reporter assay, single lab","pmids":["28822708"],"is_preprint":false},{"year":2018,"finding":"In drug-resistant basal cell carcinomas, nuclear MKL1 forms a protein complex with SRF and GLI1 near hedgehog target genes, amplifying GLI1 transcriptional activity. Cytoskeletal activation through Rho and mDia (formin) is required for SRF-MKL-driven GLI1 activation and tumor cell viability.","method":"Multidimensional genomics, Co-IP (MKL1-SRF-GLI1 complex), Rho/mDia pathway inhibition, nuclear MKL1 staining as biomarker","journal":"Nature medicine","confidence":"High","confidence_rationale":"Tier 2 / Strong — Co-IP establishing novel protein complex, genomic analysis, pathway epistasis, validated in human tumor specimens","pmids":["29400712"],"is_preprint":false},{"year":2018,"finding":"HDAC6 co-immunoprecipitates with MRTF-A and deacetylates it; pharmacological inhibition of HDAC6 with tubastatin A increases MRTF-A acetylation and total MRTF-A protein, enhancing SRF transcriptional activity in vascular smooth muscle cells.","method":"Co-IP, HDAC6 inhibition (tubastatin A), HDAC6 knockdown, luciferase reporter, in vivo carotid injury model","journal":"JACC. Basic to translational science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus functional assays in vitro and in vivo, single lab","pmids":["30623138"],"is_preprint":false},{"year":2018,"finding":"MRTF-A mediates macrophage ROS production during acute kidney injury by promoting NOX1 transcription. Mechanistically, MRTF-A interacts with the acetyltransferase MYST1 to regulate histone H4K16 acetylation at NOX1/NOX4 gene promoters. Macrophage-specific MRTF-A deletion ameliorates AKI in mice.","method":"Macrophage-specific KO, ChIP, Co-IP (MRTF-A-MYST1), in vitro NOX promoter assay, AKI mouse models","journal":"Biochimica et biophysica acta. Molecular basis of disease","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, ChIP, cell-type-specific KO, single lab","pmids":["29908908"],"is_preprint":false},{"year":2019,"finding":"MKL1 directly binds the CTGF promoter by interacting with SMAD3, activating CTGF transcription in renal tubular epithelial cells. MKL1 mediates interplay between p300 and WDR5 to regulate CTGF transcription. Genetic or pharmacological inhibition of MKL1 reduces renal fibrosis in vivo.","method":"ChIP, Co-IP (MKL1-SMAD3-p300-WDR5 interactions), UUO mouse model of fibrosis, siRNA knockdown","journal":"Journal of cellular physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP plus multiple Co-IPs, in vivo model, single lab","pmids":["31637729"],"is_preprint":false},{"year":2019,"finding":"The mRNA export factor Ddx19/Dbp5 is specifically required for nuclear import of MKL1. Ddx19 modulates the conformation of MKL1, affecting its interaction with Importin-β for efficient nuclear import. This effect requires RNA binding activity of Ddx19 but not its helicase or nuclear pore-binding activities.","method":"siRNA knockdown, nuclear localization assay, Co-IP (MKL1-Importin-β), domain mutagenesis of Ddx19, rescue experiments","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Moderate — mechanistic dissection of import pathway with domain mutagenesis and Co-IP, single focused study with multiple orthogonal methods","pmids":["25585691"],"is_preprint":false},{"year":2019,"finding":"MRTF-A directly binds the Abl1 (c-Abl) promoter via interaction with Sp1 to activate c-Abl transcription. Reciprocally, c-Abl activates ERK, which phosphorylates MRTF-A and promotes its nuclear translocation, forming a positive feedback loop contributing to hepatic stellate cell activation and liver fibrosis.","method":"ChIP (MRTF-A binding to Abl1 promoter), Co-IP (MRTF-A-Sp1), pharmacological c-Abl inhibition, nuclear fractionation, MRTF-A KO mice","journal":"Frontiers in cell and developmental biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP, Co-IP, and nuclear fractionation, single lab","pmids":["31681772"],"is_preprint":false},{"year":2019,"finding":"MKL1-actin pathway reduces chromatin accessibility and impedes somatic cell reprogramming to pluripotency. Sustained MKL1 expression yields excessive actin cytoskeleton, decreases nuclear volume, and reduces global chromatin accessibility. This block can be partially bypassed by inhibiting the Sun2-containing LINC complex, linking cytoskeletal tension to chromatin regulation.","method":"MKL1 overexpression, ATAC-seq (chromatin accessibility), nuclear volume measurement, LINC complex disruption, reprogramming assays","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Moderate — genome-wide chromatin accessibility assay plus genetic interventions and rescue experiments, single lab with multiple orthogonal approaches","pmids":["30979898"],"is_preprint":false},{"year":2019,"finding":"MRTF-A interacts with SRF to bind directly to the EREG promoter and activate EREG transcription in hepatic stellate cells (HSC). EREG stimulation promotes MRTF-A nuclear translocation in HSC, forming a feedforward loop where MRTF-A drives EREG production, and EREG in turn re-activates MRTF-A.","method":"ChIP, Co-IP (MRTF-A/SRF), MRTF-A KO mice, nuclear fractionation, siRNA knockdown","journal":"Frontiers in cell and developmental biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP and Co-IP supported by KO mice, single lab","pmids":["33520984"],"is_preprint":false},{"year":2020,"finding":"MKL1 deficiency in a second family with homozygous frameshift mutation causes severe neutrophil actin polymerization defect, strongly reduced motility/chemotactic response, and failure of firm adherence and transendothelial migration under flow. Proteomic and transcriptomic analyses confirm actin and actin-related proteins are downregulated in patient neutrophils. Non-hematopoietic primary fibroblasts show defective myofibroblast differentiation but normal migration, attributed to MKL2 compensation.","method":"Patient genetic analysis, proteomic/transcriptomic analysis, actin polymerization assay, migration/chemotaxis assay, transendothelial migration under flow, degranulation assay","journal":"Blood","confidence":"High","confidence_rationale":"Tier 2 / Strong — human loss-of-function genetics confirmed by multi-omics and multiple cellular assays, second independent family confirming first report","pmids":["32128589"],"is_preprint":false},{"year":2020,"finding":"YAP promotes myofibroblast differentiation in cardiac fibroblasts through TEAD1-driven de novo expression of MRTF-A, which then drives extracellular matrix gene expression. Genetic inhibition of fibroblast YAP attenuates cardiac fibrosis and reduces MRTF-A expression.","method":"Cardiac fibroblast-specific YAP knockout, gene expression analysis, fibrosis assessment after myocardial infarction","journal":"JACC. Basic to translational science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — cell-type-specific KO with molecular mechanism identified, single lab","pmids":["33015415"],"is_preprint":false},{"year":2020,"finding":"MRTF-A interacts with TIP60 acetyltransferase to synergistically activate iNOS transcription in macrophages during hypoxia-reoxygenation. MRTF-A directly binds the iNOS promoter; its binding is associated with trimethylated H3K4, acetylated H3K9, H3K27, and H4K16. TIP60 also forms crosstalk with the H3K4 trimethyltransferase complex at this promoter.","method":"ChIP (MRTF-A binding to iNOS promoter + histone marks), Co-IP (MRTF-A-TIP60), siRNA knockdown, MRTF-A KO mice","journal":"Frontiers in cell and developmental biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP plus Co-IP with in vivo model, single lab","pmids":["32626711"],"is_preprint":false},{"year":2021,"finding":"TGF-β upregulates MRTF-A expression in non-small-cell lung cancer cells; MRTF-A then interacts with NF-κB/p65 (rather than SRF) to facilitate p65 binding to the PDL1 promoter, activating PD-L1 transcription and promoting immune escape.","method":"Co-IP (MRTF-A/NF-κB p65), ChIP (p65 binding to PDL1 promoter), siRNA knockdown, reporter assay, syngraft tumor model","journal":"Experimental & molecular medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus ChIP with in vivo model, single lab","pmids":["34548615"],"is_preprint":false},{"year":2021,"finding":"MKL1 interacts with E2F1 to activate FOXM1 transcription in vascular smooth muscle cells. ROS-induced MKL1 phosphorylation through MK2 is essential for this MKL1-E2F1 interaction and FOXM1 trans-activation. VSMC-specific deletion of MKL1 suppresses neointima formation in mice.","method":"VSMC-specific MKL1 KO, Co-IP (MKL1-E2F1), ChIP, siRNA knockdown, MK2 inhibition, ROS assays, neointima model","journal":"Redox biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, ChIP, and cell-type-specific KO, single lab","pmids":["36587486"],"is_preprint":false},{"year":2022,"finding":"In LMNA-mutant muscle cells, ERK1/2-phosphorylated cofilin-1 (pT25-cofilin-1) binds MRTF-A in the cytoplasm, preventing SRF stimulation in the nucleus. MRTF-A/SRF inhibition decreases ATAT1 expression and thus α-tubulin acetylation. In Atat1 KO mice, left ventricular dilation and Cx43 mislocalization are observed. Tubastatin A treatment restores Cx43 localization and cardiac function in Lmna mutant mice.","method":"Co-IP (cofilin-1/MRTF-A interaction), cardiomyocytes from LMNA patient-derived iPSCs, Lmna(H222P/H222P) mice, Atat1 KO mice, tubastatin A treatment, cardiac functional assessment","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — Co-IP establishing physical interaction, multiple genetic models (patient-derived cells, two KO mouse lines), pharmacological rescue, multiple orthogonal approaches","pmids":["36550158"],"is_preprint":false},{"year":2023,"finding":"The lncRNA INKILN physically interacts with MKL1 to stabilize it and reduces MKL1 ubiquitination by protecting the physical interaction between MKL1 and the deubiquitinase USP10. INKILN depletion abolishes the physical interaction between p65 and MKL1 and blocks interleukin-1β-induced nuclear localization of both p65 and MKL1, reducing NF-κB-driven vascular smooth muscle inflammation.","method":"RNA-protein interaction assays, Co-IP (INKILN/MKL1/USP10/p65 interactions), MKL1 ubiquitination assay, siRNA knockdown, BAC transgenic mice, NF-κB reporter","journal":"Circulation","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple RNA-protein and protein-protein interaction assays, in vivo BAC transgenic mouse model, ubiquitination mechanistic readout, single lab","pmids":["37199168"],"is_preprint":false},{"year":2023,"finding":"MRTF-A interacts with TEAD1 to bind the Zeb1 promoter and activate Zeb1 transcription in renal fibroblasts. Zeb1 in turn represses IRF9 transcription, promoting fibroblast-to-myofibroblast transition. Myofibroblast-specific deletion of MRTF-A ameliorates renal fibrosis.","method":"ChIP (MRTF-A/TEAD1 at Zeb1 promoter), Co-IP, siRNA knockdown, Postn-CreERT2 x Mrtfa-flox conditional KO mice, RNA-seq","journal":"Experimental & molecular medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP plus Co-IP with cell-type-specific KO, single lab","pmids":["37121967"],"is_preprint":false},{"year":2017,"finding":"Emerin is required for Mkl1 nuclear accumulation and maximal SRF-Mkl1-dependent gene expression in a substrate stiffness-dependent manner in fibroblasts. Emerin is dispensable on more compliant substrates. A constitutively active Mkl1 bypasses the requirement for Emerin.","method":"Emerin knockout fibroblasts, nuclear localization assay for Mkl1, luciferase reporter, polyacrylamide gel substrates of defined stiffness, constitutively active Mkl1 rescue","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KO with nuclear localization assay and functional reporter, epistasis with constitutively active Mkl1, single lab","pmids":["28576971"],"is_preprint":false},{"year":2014,"finding":"S1P-induced RhoA activation leads to nuclear accumulation of MRTF-A in cardiomyocytes. Pharmacological inhibition or siRNA knockdown of MRTF-A significantly diminishes S1P-mediated CCN1 expression, and S1P-induced cardioprotection against simulated ischemia/reperfusion is significantly reduced by MRTF-A inhibition.","method":"Nuclear accumulation assay, MRTF-A knockdown/pharmacological inhibition, CCN1 expression assay, simulated I/R apoptosis assay, RhoA manipulation","journal":"Journal of molecular and cellular cardiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple pharmacological and genetic interventions, functional cardioprotection readout, single lab","pmids":["25106095"],"is_preprint":false},{"year":2019,"finding":"MKL1 interacts with AP-1 and SMAD3 to trans-activate CTGF in hepatocytes in response to high glucose treatment, contributing to hepatic stellate cell activation in a non-cell-autonomous manner. Genetic ablation or pharmacological inhibition of MKL1 in hepatocytes abrogates the pro-fibrogenic effect.","method":"ChIP (MKL1 binding to CTGF promoter), Co-IP (MKL1-AP-1-SMAD3), conditioned medium experiments, siRNA knockdown, MKL1 KO mice","journal":"Biochimica et biophysica acta. Gene regulatory mechanisms","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP plus Co-IP with KO model, single lab","pmids":["30951901"],"is_preprint":false}],"current_model":"MRTF-A/MKL1 is a signal-regulated transcriptional coactivator that is held inactive in the cytoplasm through direct binding of monomeric G-actin to its N-terminal RPEL domain; signals that activate RhoA-driven actin polymerization reduce free G-actin, releasing MRTF-A to translocate to the nucleus (facilitated by Importin-β and the RNA helicase Ddx19), where it binds SRF at CArG-box-containing promoters to drive expression of cytoskeletal, immediate-early, and cell-identity genes. Nuclear accumulation is positively regulated by ERK-mediated S98 phosphorylation (inhibiting G-actin re-assembly), by PCAF-mediated lysine acetylation (which enhances nuclear retention and NF-κB co-complex formation), and by filamin A binding; it is negatively regulated by Crm1-dependent nuclear export (potentiated by S33 phosphorylation), by SUMO-1 modification at K499/K576/K624, and by re-sequestration with G-actin. Beyond SRF, MRTF-A also co-operates with NF-κB/p65, SMAD3, AP-1, STAT3, C/EBPβ, TEAD1, and ETS factors, and recruits chromatin-modifying complexes (PCAF, TIP60, MYST1, SMYD3, SET1, ASH2-H3K4 methyltransferase, BRG1/Brg1-Brm remodelers) to activate target gene transcription. MRTF-A is physiologically required for mammary gland lactation, megakaryocyte/platelet maturation, VSMC identity, cardiomyocyte identity, and immune-cell cytoskeletal function, and its dysregulation drives fibrosis, vascular remodeling, cardiomyopathy, and cancer metastasis."},"narrative":{"mechanistic_narrative":"MRTFA (MKL1/MAL/BSAC) is a signal-regulated transcriptional coactivator that couples the state of the actin cytoskeleton to a gene-expression program controlling cell identity, migration, and tissue remodeling, principally by partnering with serum response factor (SRF) at CArG-box promoters [PMID:12019265, PMID:15329155, PMID:18337547]. Its activity is gated by actin dynamics: monomeric G-actin tethers MRTF-A in the cytoplasm, and RhoA-driven actin polymerization (triggered by stimuli such as S1P, thymosin β4, or cell spreading) depletes free G-actin to permit nuclear translocation, whereas conditions that raise G-actin—as during adipogenic differentiation—retain it cytoplasmically and license antagonistic programs such as PPARγ-driven differentiation [PMID:24340092, PMID:24569594, PMID:24910328, PMID:25106095]. Nucleocytoplasmic shuttling is further controlled by an Importin-β import pathway facilitated by the RNA-binding helicase Ddx19 and by WDR1, by Crm1-dependent export, and by the nuclear-envelope proteins lamin A/C and emerin acting through actin dynamics in a substrate-stiffness-dependent manner [PMID:25585691, PMID:28822708, PMID:23644458, PMID:28576971, PMID:27304076]. MRTF-A activity is tuned post-translationally: ERK-mediated S98 phosphorylation promotes nuclear import while S33 phosphorylation potentiates nuclear export [PMID:27304076]; SUMO-1 modification at K499/K576/K624 represses transcriptional output [PMID:16098147]; PCAF-mediated acetylation enhances nuclear retention and NF-κB co-complex formation, an acetylation reversed by HDAC6 [PMID:28571745, PMID:30623138]; and lncRNA INKILN stabilizes the protein by protecting a USP10 deubiquitination interaction [PMID:37199168]. Once nuclear, MRTF-A functions as a chromatin-remodeling hub, recruiting H3K4 methyltransferase complexes (ASH2, SET1, WDR5), acetyltransferases (PCAF, TIP60/MYST1, SMYD3, p300) and BRG1/Brm remodelers to target promoters, and cooperating beyond SRF with NF-κB/p65, SMAD3, AP-1, STAT3, TEAD1, GLI1, E2F1, and Sp1 to drive cytoskeletal, adhesive, pro-fibrotic, and pro-migratory genes [PMID:25746000, PMID:26241940, PMID:28571745, PMID:28385531, PMID:29908908, PMID:32626711, PMID:31637729, PMID:24189459]. Genetically, MRTF-A and its paralog MKL2 are required for megakaryocyte/platelet maturation and mammary gland lactation, and human loss-of-function mutations cause a primary immunodeficiency marked by defective F-actin assembly, impaired neutrophil migration, and abolished phagocytosis [PMID:16847333, PMID:19136660, PMID:22806889, PMID:26224645, PMID:32128589]. Dysregulated MRTF-A drives pathological vascular remodeling, cardiac hypertrophy and fibrosis, renal and hepatic fibrosis, and cancer cell migration, invasion, and immune escape [PMID:23103763, PMID:25446178, PMID:31637729, PMID:37121967, PMID:34548615].","teleology":[{"year":2002,"claim":"Established MRTFA as a nuclear transcriptional activator acting at CArG-box promoters, defining the domains required for its activity and linking transcriptional output to cell survival.","evidence":"Functional cloning, reporter assays, and domain-deletion mutagenesis in DKO MEFs","pmids":["12019265"],"confidence":"Medium","gaps":["Did not identify the upstream signal or partner directing CArG-box selectivity","Anti-apoptotic mechanism left undefined"]},{"year":2004,"claim":"Placed MRTFA in the Rho GTPase pathway as a selective coactivator of SRF for a defined subset of immediate-early genes, distinguishing it from the TCF/Elk1 branch.","evidence":"Microarray profiling with a dominant-negative MKL1 cell line","pmids":["15329155"],"confidence":"Medium","gaps":["Mechanism coupling Rho to MKL1 not resolved","Target gene selectivity determinants unknown"]},{"year":2005,"claim":"Identified SUMOylation as a repressive post-translational switch on MRTFA, showing modification at three lysines dampens transcription without disrupting SRF binding.","evidence":"Yeast two-hybrid (UBC9), in vitro SUMOylation reconstitution, acceptor-site mutagenesis with reporter readout","pmids":["16098147"],"confidence":"High","gaps":["How SUMOylation mechanistically represses transcription unclear","Physiological contexts of SUMO regulation untested"]},{"year":2006,"claim":"Demonstrated an essential, non-redundant in vivo requirement for MRTFA as an SRF coactivator in mammary myoepithelial cells and showed it controls smooth-muscle marker genes via CArG elements.","evidence":"Mkl1 knockout mice with histology and expression analysis; ChIP and gain/loss-of-function in VSMCs","pmids":["16847333","16987998"],"confidence":"High","gaps":["Did not address paralog (MKL2) compensation","Upstream signal controlling tissue-specific activity not defined"]},{"year":2008,"claim":"Showed MRTFA directly drives α-SMA via SRF/CArG occupancy downstream of TGF-β1 and is itself controlled by proteasomal turnover, and revealed an oncogenic fusion that forces nuclear localization and aberrant target activation.","evidence":"ChIP, siRNA, GFP-fusion localization, proteasome inhibition; localization and reciprocal Co-IP for OTT-MKL1 fusion","pmids":["18337547","18667423"],"confidence":"High","gaps":["Ubiquitin ligase mediating turnover not identified","Generality of fusion mechanism to other cancers untested"]},{"year":2009,"claim":"Established MRTFA as a driver of megakaryocyte differentiation and ploidy through SRF, using epistasis to confirm SRF dependence in vivo.","evidence":"MKL1 overexpression in HEL and CD34+ cells, SRF knockdown, Mkl1 knockout mice with platelet phenotyping","pmids":["19136660"],"confidence":"High","gaps":["SRF-independent contributions not yet separated","Mechanism of ploidy control unresolved"]},{"year":2010,"claim":"Extended actin-gated MRTFA-SRF signaling to neurons, linking synaptic activation and an activin-SCAI corepressor axis to structural gene expression and dendritic complexity.","evidence":"Immunofluorescence localization, behavioral conditioning, SCAI manipulation, SRF reporter assays","pmids":["20016002","20709749"],"confidence":"Medium","gaps":["Direct neuronal target genes not mapped","How SCAI mechanistically represses MKL-SRF unclear"]},{"year":2012,"claim":"Resolved paralog redundancy by showing MKL1/MKL2 double knockout produces more severe megakaryocyte and platelet defects, and revealed both SRF-dependent and SRF-independent transcriptional activities; further defined MRTFA control of adhesion/migration genes and pathological VSMC remodeling.","evidence":"Conditional Mkl1/Mkl2 DKO with EM and expression comparison to SRF KO; ChIP and rescue in cancer cells; MRTF-A KO injury and atherosclerosis models","pmids":["22806889","22223881","23103763"],"confidence":"High","gaps":["Molecular basis of SRF-independent activity not defined","Mechanism by which miR-1 loss induces MRTF-A only partially characterized"]},{"year":2013,"claim":"Connected nuclear-envelope architecture (lamin A/C, emerin) and cell-shape/cytoskeletal tension to MRTFA nuclear shuttling via actin dynamics, and revealed MRTFA as a recruiter of chromatin-modifying machinery (Brg1/Brm, SMYD3) at target promoters.","evidence":"Live-cell imaging and emerin rescue in Lmna-/- cells; micro-contact printing with blebbistatin; ChIP and Co-IP for chromatin complexes","pmids":["23644458","24340092","23625963","24189459"],"confidence":"High","gaps":["How emerin/lamin alter actin dynamics mechanistically incomplete","Generality of each chromatin-modifier recruitment across promoters untested"]},{"year":2014,"claim":"Dissected actin-gated import in detail—G-actin sequestration during adipogenesis blocks MRTFA, while thymosin β4 and S1P promote import—and broadened the partner repertoire to STAT3 and AP-1 driving migration and hypertrophy programs.","evidence":"Actin manipulation, Co-IP, subcellular fractionation, PPARγ reporters; MRTF-A/B KO ischemia models; STAT3 and AP-1 Co-IP and ChIP","pmids":["24569594","24910328","25446178","25038455","25106095"],"confidence":"High","gaps":["Stoichiometry and competition between actin and partner binding unresolved","How partner choice (SRF vs STAT3 vs AP-1) is determined unclear"]},{"year":2015,"claim":"Demonstrated a SAP-domain, SRF-independent arm of MRTFA signaling responsive to mechanical strain, established human loss-of-function immunodeficiency from defective F-actin assembly, and added FLNA as a positive F-actin-to-MRTFA transducer plus epigenetic activation of MMP9 and p21.","evidence":"SAP-deleted Mkl1 tumor models; patient genetics with cellular reconstitution; FLNA Co-IP/domain mapping/mutagenesis; ChIP for MMP9 and p21","pmids":["25999144","26224645","26554816","25746000","25888165","26241940"],"confidence":"High","gaps":["Molecular targets of SAP-domain signaling incompletely defined","How FLNA conformationally transduces F-actin status to MRTFA unresolved"]},{"year":2016,"claim":"Provided a comprehensive phosphorylation map showing ERK-S98 promotes import and S33 potentiates Crm1-dependent export, identified stress-induced p38/MK2 sites of uncertain consequence, and revealed PPARγ-direct and STAT3-DNMT1 mechanisms plus SAP-dependent profilin control.","evidence":"Mass-spec phosphosite mapping, multi-site mutagenesis, Crm1 inhibition, in vitro G-actin binding; MK2/3 KO cells; Co-IP with PPARγ and STAT3; bisulfite sequencing","pmids":["27304076","27492266","28125644","25854163","28546428"],"confidence":"High","gaps":["Functional role of p38/MK2 sites remained undetermined in tested conditions","Kinase responsible for each import/export site not fully assigned"]},{"year":2017,"claim":"Established acetylation by PCAF as a positive switch enhancing nuclear retention and NF-κB co-complex formation, and defined SET1/BRG1 recruitment via NF-κB and WDR1/importin-mediated import in cancer contexts, with emerin acting in a stiffness-dependent manner.","evidence":"Acetylation assays, four-lysine mutant, ChIP, nuclear fractionation; ChIP/Co-IP for SET1-BRG1; nuclear fractionation and reporter for WDR1; emerin KO with stiffness substrates","pmids":["28571745","28385531","28822708","28576971"],"confidence":"High","gaps":["Acetyltransferase/deacetylase balance in vivo not quantified","Direct demonstration of importin conformational change incomplete"]},{"year":2018,"claim":"Identified HDAC6 as the deacetylase counteracting MRTFA acetylation, placed MRTFA in a SRF-GLI1 hedgehog co-complex driving drug-resistant tumor viability, and showed MYST1-dependent H4K16 acetylation at NOX promoters in macrophage oxidative responses.","evidence":"Co-IP and tubastatin A in VSMCs; Co-IP for MKL1-SRF-GLI1 with genomics and pathway inhibition; macrophage-specific KO with ChIP and Co-IP","pmids":["30623138","29400712","29908908"],"confidence":"High","gaps":["How nuclear MKL1 selects GLI1 vs SRF targets unresolved","Direct enzymatic kinetics of MRTFA-MYST1 cooperation not measured"]},{"year":2019,"claim":"Mechanistically defined the import machinery (Ddx19 modulating MKL1 conformation for Importin-β), revealed MRTFA-driven feedforward fibrotic loops (Abl1/Sp1, EREG, CTGF via SMAD3/AP-1/p300/WDR5), and showed sustained MKL1-actin signaling represses chromatin accessibility to block reprogramming.","evidence":"Ddx19 domain mutagenesis and Co-IP; ChIP/Co-IP and KO mice for Abl1, EREG, CTGF; ATAC-seq with LINC-complex disruption","pmids":["25585691","31681772","33520984","31637729","30951901","30979898"],"confidence":"High","gaps":["How Ddx19 RNA-binding alters MKL1 conformation structurally unknown","Mechanism linking cytoskeletal tension to global chromatin accessibility incompletely defined"]},{"year":2020,"claim":"Confirmed human MRTFA immunodeficiency in a second family with multi-omic and functional neutrophil defects (with MKL2 compensation in fibroblasts), placed MRTFA downstream of YAP/TEAD1 in cardiac myofibroblast differentiation, and added TIP60-dependent histone marks at the iNOS promoter.","evidence":"Patient genetics with proteomics/transcriptomics and flow-based migration assays; fibroblast-specific YAP KO; ChIP and Co-IP with MRTF-A KO mice","pmids":["32128589","33015415","32626711"],"confidence":"High","gaps":["Determinants of MKL2 compensation across cell types unclear","Whether YAP-TEAD1 induction of MRTF-A is direct vs indirect not fully resolved"]},{"year":2021,"claim":"Showed MRTFA can act through NF-κB/p65 (not SRF) to drive PD-L1 and immune escape, and through E2F1 with ROS/MK2-dependent phosphorylation to activate FOXM1 in vascular remodeling.","evidence":"Co-IP, ChIP, reporter and syngraft tumor model for PD-L1; VSMC-specific KO, Co-IP, ChIP and MK2 inhibition for FOXM1","pmids":["34548615","36587486"],"confidence":"Medium","gaps":["Switch governing SRF-dependent vs NF-κB/E2F1-dependent modes unresolved","Single-lab interaction data without reciprocal structural validation"]},{"year":2022,"claim":"Linked LMNA-mutant cardiomyopathy to cytoplasmic sequestration of MRTFA by phospho-cofilin-1, with downstream ATAT1/α-tubulin acetylation defects and pharmacological rescue, integrating actin/microtubule and nuclear-envelope biology.","evidence":"Co-IP, patient-derived iPSC cardiomyocytes, Lmna(H222P) and Atat1 KO mice, tubastatin A rescue with cardiac functional assessment","pmids":["36550158"],"confidence":"High","gaps":["Generality of cofilin-1 sequestration beyond LMNA disease unknown","Quantitative contribution of MRTFA-SRF vs other ATAT1 regulators not isolated"]},{"year":2023,"claim":"Identified lncRNA INKILN as a stabilizer of MKL1 (protecting USP10 deubiquitination and enabling p65 co-complex formation) and extended the TEAD1 partnership to a Zeb1/IRF9 axis in renal myofibroblast transition.","evidence":"RNA-protein and protein-protein interaction assays, ubiquitination assay, BAC transgenic mice; ChIP/Co-IP with myofibroblast-specific MRTF-A KO and RNA-seq","pmids":["37199168","37121967"],"confidence":"High","gaps":["Structural basis of INKILN-MKL1-USP10 protection unknown","How MRTFA partitions between SRF and TEAD1 promoters not defined"]},{"year":null,"claim":"It remains unresolved how MRTFA selects among its many transcription-factor partners (SRF, NF-κB, SMAD3, STAT3, AP-1, TEAD1, GLI1, E2F1, Sp1) and chromatin-modifier complexes at a given promoter, and how the integrated phosphorylation/acetylation/SUMOylation/ubiquitination code is read out to dictate context-specific outputs.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of MRTFA bound to alternative partners","Quantitative rules for SRF-dependent vs SRF-independent (SAP-domain) signaling undefined","Combinatorial PTM logic governing localization and partner choice unmapped"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[0,1,5,11,22]},{"term_id":"GO:0003677","term_label":"DNA binding","supporting_discovery_ids":[0,5,26]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[17,24,48]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[32,35,46]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0,5,13,27,39]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[17,27,48]}],"pathway":[{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[0,1,5,22]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[1,17,24,52]},{"term_id":"R-HSA-4839726","term_label":"Chromatin organization","supporting_discovery_ids":[14,22,23,32,41]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[3,7,10]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[12,19,38,46,50]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[21,43,32]}],"complexes":["MRTF-A/SRF complex","H3K4 methyltransferase complex (SET1/ASH2/WDR5)","MKL1-NF-κB/p65 co-complex","SRF-MKL1-GLI1 complex"],"partners":["SRF","RELA","SMAD3","STAT3","FLNA","TEAD1","PCAF","DDX19"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q969V6","full_name":"Myocardin-related transcription factor A","aliases":["MKL/myocardin-like protein 1","Megakaryoblastic leukemia 1 protein","Megakaryocytic acute leukemia protein"],"length_aa":931,"mass_kda":98.9,"function":"Transcription coactivator that associates with the serum response factor (SRF) transcription factor to control expression of genes regulating the cytoskeleton during development, morphogenesis and cell migration (PubMed:26224645). The SRF-MRTFA complex activity responds to Rho GTPase-induced changes in cellular globular actin (G-actin) concentration, thereby coupling cytoskeletal gene expression to cytoskeletal dynamics. MRTFA binds G-actin via its RPEL repeats, regulating activity of the MRTFA-SRF complex. Activity is also regulated by filamentous actin (F-actin) in the nucleus","subcellular_location":"Cytoplasm; Nucleus","url":"https://www.uniprot.org/uniprotkb/Q969V6/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/MRTFA","classification":"Not Classified","n_dependent_lines":22,"n_total_lines":1208,"dependency_fraction":0.018211920529801324},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/MRTFA","total_profiled":1310},"omim":[{"mim_id":"620941","title":"SYNAPTOPODIN 2; SYNPO2","url":"https://www.omim.org/entry/620941"},{"mim_id":"619222","title":"SUPPRESSOR OF CANCER CELL INVASION; SCAI","url":"https://www.omim.org/entry/619222"},{"mim_id":"618976","title":"MYOCARDIN-INDUCED SMOOTH MUSCLE LONG NONCODING RNA, INDUCER OF DIFFERENTIATION; MYOSLID","url":"https://www.omim.org/entry/618976"},{"mim_id":"618847","title":"IMMUNODEFICIENCY 66; IMD66","url":"https://www.omim.org/entry/618847"},{"mim_id":"609747","title":"ACTIN-BINDING RHO-ACTIVATING PROTEIN; ABRA","url":"https://www.omim.org/entry/609747"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"},{"location":"Nuclear membrane","reliability":"Additional"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/MRTFA"},"hgnc":{"alias_symbol":["KIAA1438","MAL","MRTF-A","BSAC","MKL"],"prev_symbol":["MKL1"]},"alphafold":{"accession":"Q969V6","domains":[{"cath_id":"1.20.5","chopping":"12-46","consensus_level":"medium","plddt":96.0709,"start":12,"end":46},{"cath_id":"1.20.5","chopping":"48-78","consensus_level":"medium","plddt":94.369,"start":48,"end":78}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q969V6","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q969V6-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q969V6-F1-predicted_aligned_error_v6.png","plddt_mean":55.03},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MRTFA","jax_strain_url":"https://www.jax.org/strain/search?query=MRTFA"},"sequence":{"accession":"Q969V6","fasta_url":"https://rest.uniprot.org/uniprotkb/Q969V6.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q969V6/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q969V6"}},"corpus_meta":[{"pmid":"23644458","id":"PMC_23644458","title":"Lamin A/C and emerin regulate MKL1-SRF activity by modulating actin dynamics.","date":"2013","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/23644458","citation_count":369,"is_preprint":false},{"pmid":"24569594","id":"PMC_24569594","title":"Regulation of MKL1 via actin cytoskeleton dynamics drives adipocyte differentiation.","date":"2014","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/24569594","citation_count":146,"is_preprint":false},{"pmid":"16847333","id":"PMC_16847333","title":"Acute myeloid leukemia-associated Mkl1 (Mrtf-a) is a key regulator of mammary gland function.","date":"2006","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/16847333","citation_count":144,"is_preprint":false},{"pmid":"15329155","id":"PMC_15329155","title":"Expression profiling of serum inducible genes identifies a subset of SRF target genes that are MKL dependent.","date":"2004","source":"BMC molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/15329155","citation_count":133,"is_preprint":false},{"pmid":"33015415","id":"PMC_33015415","title":"Blockade of Fibroblast YAP Attenuates Cardiac Fibrosis and Dysfunction Through MRTF-A Inhibition.","date":"2020","source":"JACC. Basic to translational science","url":"https://pubmed.ncbi.nlm.nih.gov/33015415","citation_count":122,"is_preprint":false},{"pmid":"27435395","id":"PMC_27435395","title":"miR-206 Inhibits Stemness and Metastasis of Breast Cancer by Targeting MKL1/IL11 Pathway.","date":"2016","source":"Clinical cancer research : an official journal of the American Association for Cancer Research","url":"https://pubmed.ncbi.nlm.nih.gov/27435395","citation_count":108,"is_preprint":false},{"pmid":"16987998","id":"PMC_16987998","title":"Platelet-derived growth factor-BB represses smooth muscle cell marker genes via changes in binding of MKL factors and histone deacetylases to their promoters.","date":"2006","source":"American journal of physiology. Cell physiology","url":"https://pubmed.ncbi.nlm.nih.gov/16987998","citation_count":91,"is_preprint":false},{"pmid":"29400712","id":"PMC_29400712","title":"Noncanonical hedgehog pathway activation through SRF-MKL1 promotes drug resistance in basal cell carcinomas.","date":"2018","source":"Nature medicine","url":"https://pubmed.ncbi.nlm.nih.gov/29400712","citation_count":89,"is_preprint":false},{"pmid":"23103763","id":"PMC_23103763","title":"Reciprocal expression of MRTF-A and myocardin is crucial for pathological vascular remodelling in mice.","date":"2012","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/23103763","citation_count":89,"is_preprint":false},{"pmid":"12019265","id":"PMC_12019265","title":"Identification of a novel transcriptional activator, BSAC, by a functional cloning to inhibit tumor necrosis factor-induced cell death.","date":"2002","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12019265","citation_count":83,"is_preprint":false},{"pmid":"25955164","id":"PMC_25955164","title":"A Role of Myocardin Related Transcription Factor-A (MRTF-A) in Scleroderma Related Fibrosis.","date":"2015","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/25955164","citation_count":82,"is_preprint":false},{"pmid":"24910328","id":"PMC_24910328","title":"MRTF-A controls vessel growth and maturation by increasing the expression of CCN1 and CCN2.","date":"2014","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/24910328","citation_count":79,"is_preprint":false},{"pmid":"24340092","id":"PMC_24340092","title":"Cell adhesion and shape regulate TGF-beta1-induced epithelial-myofibroblast transition via MRTF-A signaling.","date":"2013","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/24340092","citation_count":78,"is_preprint":false},{"pmid":"28499590","id":"PMC_28499590","title":"MiR-93-5p inhibits the EMT of breast cancer cells via targeting MKL-1 and STAT3.","date":"2017","source":"Experimental cell research","url":"https://pubmed.ncbi.nlm.nih.gov/28499590","citation_count":74,"is_preprint":false},{"pmid":"31638828","id":"PMC_31638828","title":"Mechanosensitive transcriptional coactivators MRTF-A and YAP/TAZ regulate nucleus pulposus cell phenotype through cell shape.","date":"2019","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/31638828","citation_count":70,"is_preprint":false},{"pmid":"29764980","id":"PMC_29764980","title":"Interplay of cell-cell contacts and RhoA/MRTF-A signaling regulates cardiomyocyte identity.","date":"2018","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/29764980","citation_count":69,"is_preprint":false},{"pmid":"18337547","id":"PMC_18337547","title":"MKL1 mediates TGF-beta1-induced alpha-smooth muscle actin expression in human renal epithelial cells.","date":"2008","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/18337547","citation_count":69,"is_preprint":false},{"pmid":"25446178","id":"PMC_25446178","title":"Endothelial MRTF-A mediates angiotensin II induced cardiac hypertrophy.","date":"2014","source":"Journal of molecular and cellular cardiology","url":"https://pubmed.ncbi.nlm.nih.gov/25446178","citation_count":67,"is_preprint":false},{"pmid":"27304076","id":"PMC_27304076","title":"Phosphorylation acts positively and negatively to regulate MRTF-A subcellular localisation and activity.","date":"2016","source":"eLife","url":"https://pubmed.ncbi.nlm.nih.gov/27304076","citation_count":66,"is_preprint":false},{"pmid":"26224645","id":"PMC_26224645","title":"Immunodeficiency and severe susceptibility to bacterial infection associated with a loss-of-function homozygous mutation of MKL1.","date":"2015","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/26224645","citation_count":64,"is_preprint":false},{"pmid":"34548615","id":"PMC_34548615","title":"MRTF-A-NF-κB/p65 axis-mediated PDL1 transcription and expression contributes to immune evasion of non-small-cell lung cancer via TGF-β.","date":"2021","source":"Experimental & molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/34548615","citation_count":63,"is_preprint":false},{"pmid":"19136660","id":"PMC_19136660","title":"Role for MKL1 in megakaryocytic maturation.","date":"2009","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/19136660","citation_count":62,"is_preprint":false},{"pmid":"25746000","id":"PMC_25746000","title":"MKL1 potentiates lung cancer cell migration and invasion by epigenetically activating MMP9 transcription.","date":"2015","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/25746000","citation_count":59,"is_preprint":false},{"pmid":"22223881","id":"PMC_22223881","title":"MAL/MRTF-A controls migration of non-invasive cells by upregulation of cytoskeleton-associated proteins.","date":"2012","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/22223881","citation_count":59,"is_preprint":false},{"pmid":"37199168","id":"PMC_37199168","title":"INKILN is a Novel Long Noncoding RNA Promoting Vascular Smooth Muscle Inflammation via Scaffolding MKL1 and USP10.","date":"2023","source":"Circulation","url":"https://pubmed.ncbi.nlm.nih.gov/37199168","citation_count":57,"is_preprint":false},{"pmid":"33667992","id":"PMC_33667992","title":"MKL1 cooperates with p38MAPK to promote vascular senescence, inflammation, and abdominal aortic aneurysm.","date":"2021","source":"Redox biology","url":"https://pubmed.ncbi.nlm.nih.gov/33667992","citation_count":53,"is_preprint":false},{"pmid":"24189459","id":"PMC_24189459","title":"Histone methyltransferase SMYD3 promotes MRTF-A-mediated transactivation of MYL9 and migration of MCF-7 breast cancer cells.","date":"2013","source":"Cancer letters","url":"https://pubmed.ncbi.nlm.nih.gov/24189459","citation_count":53,"is_preprint":false},{"pmid":"29908908","id":"PMC_29908908","title":"Myocardin-related transcription factor A (MRTF-A) contributes to acute kidney injury by regulating macrophage ROS production.","date":"2018","source":"Biochimica et biophysica acta. Molecular basis of disease","url":"https://pubmed.ncbi.nlm.nih.gov/29908908","citation_count":52,"is_preprint":false},{"pmid":"36550158","id":"PMC_36550158","title":"Actin-microtubule cytoskeletal interplay mediated by MRTF-A/SRF signaling promotes dilated cardiomyopathy caused by LMNA mutations.","date":"2022","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/36550158","citation_count":51,"is_preprint":false},{"pmid":"20816842","id":"PMC_20816842","title":"Megakaryoblastic leukemia protein-1 (MKL1): Increasing evidence for an involvement in cancer progression and metastasis.","date":"2010","source":"The international journal of biochemistry & cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/20816842","citation_count":50,"is_preprint":false},{"pmid":"32315812","id":"PMC_32315812","title":"MKL1/miR-5100/CAAP1 loop regulates autophagy and apoptosis in gastric cancer cells.","date":"2020","source":"Neoplasia (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/32315812","citation_count":50,"is_preprint":false},{"pmid":"29391067","id":"PMC_29391067","title":"LncRNA HOTAIR promotes cell migration and invasion by regulating MKL1 via inhibition miR206 expression in HeLa cells.","date":"2018","source":"Cell communication and signaling : CCS","url":"https://pubmed.ncbi.nlm.nih.gov/29391067","citation_count":47,"is_preprint":false},{"pmid":"22806889","id":"PMC_22806889","title":"MKL1 and MKL2 play redundant and crucial roles in megakaryocyte maturation and platelet formation.","date":"2012","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/22806889","citation_count":45,"is_preprint":false},{"pmid":"26241940","id":"PMC_26241940","title":"MKL1 is an epigenetic modulator of TGF-β induced fibrogenesis.","date":"2015","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/26241940","citation_count":44,"is_preprint":false},{"pmid":"26554816","id":"PMC_26554816","title":"Filamin A interacts with the coactivator MKL1 to promote the activity of the transcription factor SRF and cell migration.","date":"2015","source":"Science signaling","url":"https://pubmed.ncbi.nlm.nih.gov/26554816","citation_count":44,"is_preprint":false},{"pmid":"23625963","id":"PMC_23625963","title":"Megakaryocytic leukemia 1 (MKL1) ties the epigenetic machinery to hypoxia-induced transactivation of endothelin-1.","date":"2013","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/23625963","citation_count":44,"is_preprint":false},{"pmid":"20709749","id":"PMC_20709749","title":"Involvement of the serum response factor coactivator megakaryoblastic leukemia (MKL) in the activin-regulated dendritic complexity of rat cortical neurons.","date":"2010","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/20709749","citation_count":43,"is_preprint":false},{"pmid":"30384218","id":"PMC_30384218","title":"Matrix stiffness regulates epithelial-mesenchymal transition via cytoskeletal remodeling and MRTF-A translocation in osteosarcoma cells.","date":"2018","source":"Journal of the mechanical behavior of biomedical materials","url":"https://pubmed.ncbi.nlm.nih.gov/30384218","citation_count":42,"is_preprint":false},{"pmid":"31637729","id":"PMC_31637729","title":"MKL1 mediates TGF-β-induced CTGF transcription to promote renal fibrosis.","date":"2019","source":"Journal of cellular physiology","url":"https://pubmed.ncbi.nlm.nih.gov/31637729","citation_count":41,"is_preprint":false},{"pmid":"30979898","id":"PMC_30979898","title":"MKL1-actin pathway restricts chromatin accessibility and prevents mature pluripotency activation.","date":"2019","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/30979898","citation_count":40,"is_preprint":false},{"pmid":"27751947","id":"PMC_27751947","title":"MRTF-A signaling regulates the acquisition of the contractile phenotype in dedifferentiated chondrocytes.","date":"2016","source":"Matrix biology : journal of the International Society for Matrix Biology","url":"https://pubmed.ncbi.nlm.nih.gov/27751947","citation_count":40,"is_preprint":false},{"pmid":"36174881","id":"PMC_36174881","title":"m6A transferase METTL3 regulates endothelial-mesenchymal transition in diabetic retinopathy via lncRNA SNHG7/KHSRP/MKL1 axis.","date":"2022","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/36174881","citation_count":40,"is_preprint":false},{"pmid":"25038455","id":"PMC_25038455","title":"MRTF-A and STAT3 synergistically promote breast cancer cell migration.","date":"2014","source":"Cellular signalling","url":"https://pubmed.ncbi.nlm.nih.gov/25038455","citation_count":36,"is_preprint":false},{"pmid":"29807221","id":"PMC_29807221","title":"MRTF-A mediates the activation of COL1A1 expression stimulated by multiple signaling pathways in human breast cancer cells.","date":"2018","source":"Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie","url":"https://pubmed.ncbi.nlm.nih.gov/29807221","citation_count":35,"is_preprint":false},{"pmid":"28114277","id":"PMC_28114277","title":"The novel MKL target gene myoferlin modulates expansion and senescence of hepatocellular carcinoma.","date":"2017","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/28114277","citation_count":34,"is_preprint":false},{"pmid":"28571745","id":"PMC_28571745","title":"Acetylation of MKL1 by PCAF regulates pro-inflammatory transcription.","date":"2017","source":"Biochimica et biophysica acta. Gene regulatory mechanisms","url":"https://pubmed.ncbi.nlm.nih.gov/28571745","citation_count":34,"is_preprint":false},{"pmid":"33500406","id":"PMC_33500406","title":"MKL1-induced lncRNA SNHG18 drives the growth and metastasis of non-small cell lung cancer via the miR-211-5p/BRD4 axis.","date":"2021","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/33500406","citation_count":34,"is_preprint":false},{"pmid":"30623138","id":"PMC_30623138","title":"HDAC6 Regulates the MRTF-A/SRF Axis and Vascular Smooth Muscle Cell Plasticity.","date":"2018","source":"JACC. Basic to translational science","url":"https://pubmed.ncbi.nlm.nih.gov/30623138","citation_count":33,"is_preprint":false},{"pmid":"24758171","id":"PMC_24758171","title":"MKL1/2 and ELK4 co-regulate distinct serum response factor (SRF) transcription programs in macrophages.","date":"2014","source":"BMC genomics","url":"https://pubmed.ncbi.nlm.nih.gov/24758171","citation_count":32,"is_preprint":false},{"pmid":"32128589","id":"PMC_32128589","title":"MKL1 deficiency results in a severe neutrophil motility defect due to impaired actin polymerization.","date":"2020","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/32128589","citation_count":32,"is_preprint":false},{"pmid":"25106095","id":"PMC_25106095","title":"Induction of the matricellular protein CCN1 through RhoA and MRTF-A contributes to ischemic cardioprotection.","date":"2014","source":"Journal of molecular and cellular cardiology","url":"https://pubmed.ncbi.nlm.nih.gov/25106095","citation_count":32,"is_preprint":false},{"pmid":"36587486","id":"PMC_36587486","title":"MKL1 fuels ROS-induced proliferation of vascular smooth muscle cells by modulating FOXM1 transcription.","date":"2022","source":"Redox biology","url":"https://pubmed.ncbi.nlm.nih.gov/36587486","citation_count":31,"is_preprint":false},{"pmid":"31356989","id":"PMC_31356989","title":"An interaction between MKL1, BRG1, and C/EBPβ mediates palmitate induced CRP transcription in hepatocytes.","date":"2019","source":"Biochimica et biophysica acta. Gene regulatory mechanisms","url":"https://pubmed.ncbi.nlm.nih.gov/31356989","citation_count":31,"is_preprint":false},{"pmid":"16098147","id":"PMC_16098147","title":"Transcriptional activity of megakaryoblastic leukemia 1 (MKL1) is repressed by SUMO modification.","date":"2005","source":"Genes to cells : devoted to molecular & cellular mechanisms","url":"https://pubmed.ncbi.nlm.nih.gov/16098147","citation_count":31,"is_preprint":false},{"pmid":"25056592","id":"PMC_25056592","title":"The role of the MRTF-A/SRF pathway in ocular fibrosis.","date":"2014","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/25056592","citation_count":30,"is_preprint":false},{"pmid":"28822708","id":"PMC_28822708","title":"MRTF-A-miR-206-WDR1 form feedback loop to regulate breast cancer cell migration.","date":"2017","source":"Experimental cell research","url":"https://pubmed.ncbi.nlm.nih.gov/28822708","citation_count":30,"is_preprint":false},{"pmid":"30951901","id":"PMC_30951901","title":"A non-autonomous role of MKL1 in the activation of hepatic stellate cells.","date":"2019","source":"Biochimica et biophysica acta. Gene regulatory mechanisms","url":"https://pubmed.ncbi.nlm.nih.gov/30951901","citation_count":30,"is_preprint":false},{"pmid":"31681772","id":"PMC_31681772","title":"A cAbl-MRTF-A Feedback Loop Contributes to Hepatic Stellate Cell Activation.","date":"2019","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/31681772","citation_count":29,"is_preprint":false},{"pmid":"28592291","id":"PMC_28592291","title":"Tightly controlled MRTF-A activity regulates epithelial differentiation during formation of mammary acini.","date":"2017","source":"Breast cancer research : BCR","url":"https://pubmed.ncbi.nlm.nih.gov/28592291","citation_count":29,"is_preprint":false},{"pmid":"33015041","id":"PMC_33015041","title":"An MRTF-A-Sp1-PDE5 Axis Mediates Angiotensin-II-Induced Cardiomyocyte Hypertrophy.","date":"2020","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/33015041","citation_count":28,"is_preprint":false},{"pmid":"28385531","id":"PMC_28385531","title":"MKL1 links epigenetic activation of MMP2 to ovarian cancer cell migration and invasion.","date":"2017","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/28385531","citation_count":28,"is_preprint":false},{"pmid":"20016002","id":"PMC_20016002","title":"Mkl transcription cofactors regulate structural plasticity in hippocampal neurons.","date":"2009","source":"Cerebral cortex (New York, N.Y. : 1991)","url":"https://pubmed.ncbi.nlm.nih.gov/20016002","citation_count":27,"is_preprint":false},{"pmid":"32984327","id":"PMC_32984327","title":"MKL1 Mediates TGF-β Induced RhoJ Transcription to Promote Breast Cancer Cell Migration and Invasion.","date":"2020","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/32984327","citation_count":27,"is_preprint":false},{"pmid":"31409840","id":"PMC_31409840","title":"MRTF-A controls myofibroblastic differentiation of human multipotent stromal cells and their tumour-supporting function in xenograft models.","date":"2019","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/31409840","citation_count":27,"is_preprint":false},{"pmid":"28576971","id":"PMC_28576971","title":"Substrate stiffness-dependent regulation of the SRF-Mkl1 co-activator complex requires the inner nuclear membrane protein Emerin.","date":"2017","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/28576971","citation_count":27,"is_preprint":false},{"pmid":"28638990","id":"PMC_28638990","title":"Pharmacological intervention of MKL/SRF signaling by CCG-1423 impedes endothelial cell migration and angiogenesis.","date":"2017","source":"Angiogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/28638990","citation_count":26,"is_preprint":false},{"pmid":"33520984","id":"PMC_33520984","title":"Epiregulin (EREG) and Myocardin Related Transcription Factor A (MRTF-A) Form a Feedforward Loop to Drive Hepatic Stellate Cell Activation.","date":"2021","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/33520984","citation_count":25,"is_preprint":false},{"pmid":"28125644","id":"PMC_28125644","title":"SRF and MKL1 Independently Inhibit Brown Adipogenesis.","date":"2017","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/28125644","citation_count":24,"is_preprint":false},{"pmid":"34742274","id":"PMC_34742274","title":"MKL1 regulates hepatocellular carcinoma cell proliferation, migration and apoptosis via the COMPASS complex and NF-κB signaling.","date":"2021","source":"BMC cancer","url":"https://pubmed.ncbi.nlm.nih.gov/34742274","citation_count":23,"is_preprint":false},{"pmid":"32692361","id":"PMC_32692361","title":"Post-transcriptional regulation of MRTF-A by miRNAs during myogenic differentiation of myoblasts.","date":"2020","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/32692361","citation_count":23,"is_preprint":false},{"pmid":"32626711","id":"PMC_32626711","title":"An Interplay Between MRTF-A and the Histone Acetyltransferase TIP60 Mediates Hypoxia-Reoxygenation Induced iNOS Transcription in Macrophages.","date":"2020","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/32626711","citation_count":23,"is_preprint":false},{"pmid":"28546428","id":"PMC_28546428","title":"The myocardin-related transcription factor MKL co-regulates the cellular levels of two profilin isoforms.","date":"2017","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/28546428","citation_count":23,"is_preprint":false},{"pmid":"34239355","id":"PMC_34239355","title":"MiR-17-5p and MKL-1 modulate stem cell characteristics of gastric cancer cells.","date":"2021","source":"International journal of biological sciences","url":"https://pubmed.ncbi.nlm.nih.gov/34239355","citation_count":22,"is_preprint":false},{"pmid":"30337297","id":"PMC_30337297","title":"MRTFA augments megakaryocyte maturation by enhancing the SRF regulatory axis.","date":"2018","source":"Blood advances","url":"https://pubmed.ncbi.nlm.nih.gov/30337297","citation_count":22,"is_preprint":false},{"pmid":"31325438","id":"PMC_31325438","title":"p75 neurotrophin receptor regulates NGF-induced myofibroblast differentiation and collagen synthesis through MRTF-A.","date":"2019","source":"Experimental cell research","url":"https://pubmed.ncbi.nlm.nih.gov/31325438","citation_count":22,"is_preprint":false},{"pmid":"28069441","id":"PMC_28069441","title":"Transcription of HOTAIR is regulated by RhoC-MRTF-A-SRF signaling pathway in human breast cancer cells.","date":"2017","source":"Cellular signalling","url":"https://pubmed.ncbi.nlm.nih.gov/28069441","citation_count":22,"is_preprint":false},{"pmid":"33722605","id":"PMC_33722605","title":"MRTFA: A critical protein in normal and malignant hematopoiesis and beyond.","date":"2021","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/33722605","citation_count":21,"is_preprint":false},{"pmid":"27689009","id":"PMC_27689009","title":"Myocardin-related transcription factor A (MRTFA) regulates the fate of bone marrow mesenchymal stem cells and its absence in mice leads to osteopenia.","date":"2016","source":"Molecular metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/27689009","citation_count":21,"is_preprint":false},{"pmid":"27600078","id":"PMC_27600078","title":"Small-Molecule Inhibition of Rho/MKL/SRF Transcription in Prostate Cancer Cells: Modulation of Cell Cycle, ER Stress, and Metastasis Gene Networks.","date":"2016","source":"Microarrays (Basel, Switzerland)","url":"https://pubmed.ncbi.nlm.nih.gov/27600078","citation_count":21,"is_preprint":false},{"pmid":"27708220","id":"PMC_27708220","title":"Myocardin-related transcription factor A (MRTF-A) activity-dependent cell adhesion is correlated to focal adhesion kinase (FAK) activity.","date":"2016","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/27708220","citation_count":21,"is_preprint":false},{"pmid":"31128166","id":"PMC_31128166","title":"MRTF-A regulates proliferation and survival properties of pro-atherogenic macrophages.","date":"2019","source":"Journal of molecular and cellular cardiology","url":"https://pubmed.ncbi.nlm.nih.gov/31128166","citation_count":20,"is_preprint":false},{"pmid":"32675943","id":"PMC_32675943","title":"The MRTF-A/miR-155/SOX1 pathway mediates gastric cancer migration and invasion.","date":"2020","source":"Cancer cell international","url":"https://pubmed.ncbi.nlm.nih.gov/32675943","citation_count":20,"is_preprint":false},{"pmid":"35075114","id":"PMC_35075114","title":"Nogo-B promotes invasion and metastasis of nasopharyngeal carcinoma via RhoA-SRF-MRTFA pathway.","date":"2022","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/35075114","citation_count":18,"is_preprint":false},{"pmid":"37121967","id":"PMC_37121967","title":"An MRTF-A-ZEB1-IRF9 axis contributes to fibroblast-myofibroblast transition and renal fibrosis.","date":"2023","source":"Experimental & molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/37121967","citation_count":18,"is_preprint":false},{"pmid":"25888165","id":"PMC_25888165","title":"MKL1 inhibits cell cycle progression through p21 in podocytes.","date":"2015","source":"BMC molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/25888165","citation_count":18,"is_preprint":false},{"pmid":"25854163","id":"PMC_25854163","title":"MRTF-A and STAT3 promote MDA-MB-231 cell migration via hypermethylating BRSM1.","date":"2015","source":"IUBMB life","url":"https://pubmed.ncbi.nlm.nih.gov/25854163","citation_count":18,"is_preprint":false},{"pmid":"20338973","id":"PMC_20338973","title":"MRTF-A/B suppress the oncogenic properties of v-ras- and v-src-mediated transformants.","date":"2010","source":"Carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/20338973","citation_count":18,"is_preprint":false},{"pmid":"26498848","id":"PMC_26498848","title":"The MRTF-A/B function as oncogenes in pancreatic cancer.","date":"2015","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/26498848","citation_count":18,"is_preprint":false},{"pmid":"32208430","id":"PMC_32208430","title":"MRTF-A promotes angiotensin II-induced inflammatory response and aortic dissection in mice.","date":"2020","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/32208430","citation_count":17,"is_preprint":false},{"pmid":"28230854","id":"PMC_28230854","title":"Opposite effects of HDAC5 and p300 on MRTF-A-related neuronal apoptosis during ischemia/reperfusion injury in rats.","date":"2017","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/28230854","citation_count":17,"is_preprint":false},{"pmid":"18667423","id":"PMC_18667423","title":"Fusion of OTT to BSAC results in aberrant up-regulation of transcriptional activity.","date":"2008","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/18667423","citation_count":17,"is_preprint":false},{"pmid":"34420462","id":"PMC_34420462","title":"Inhibition of RhoA/MRTF-A signaling alleviates nucleus pulposus fibrosis induced by mechanical stress overload.","date":"2021","source":"Connective tissue research","url":"https://pubmed.ncbi.nlm.nih.gov/34420462","citation_count":17,"is_preprint":false},{"pmid":"27094722","id":"PMC_27094722","title":"Sphingosine 1-phosphate elicits RhoA-dependent proliferation and MRTF-A mediated gene induction in CPCs.","date":"2016","source":"Cellular signalling","url":"https://pubmed.ncbi.nlm.nih.gov/27094722","citation_count":17,"is_preprint":false},{"pmid":"25999144","id":"PMC_25999144","title":"Mechanism of irradiation-induced mammary cancer metastasis: A role for SAP-dependent Mkl1 signaling.","date":"2015","source":"Molecular oncology","url":"https://pubmed.ncbi.nlm.nih.gov/25999144","citation_count":17,"is_preprint":false},{"pmid":"34795561","id":"PMC_34795561","title":"Regulation of Dendritic Synaptic Morphology and Transcription by the SRF Cofactor MKL/MRTF.","date":"2021","source":"Frontiers in molecular neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/34795561","citation_count":16,"is_preprint":false},{"pmid":"33842533","id":"PMC_33842533","title":"MICAL2 Facilitates Gastric Cancer Cell Migration via MRTF-A-Mediated CDC42 Activation.","date":"2021","source":"Frontiers in molecular biosciences","url":"https://pubmed.ncbi.nlm.nih.gov/33842533","citation_count":16,"is_preprint":false},{"pmid":"27492266","id":"PMC_27492266","title":"Stress-dependent phosphorylation of myocardin-related transcription factor A (MRTF-A) by the p38(MAPK)/MK2 axis.","date":"2016","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/27492266","citation_count":16,"is_preprint":false},{"pmid":"27939432","id":"PMC_27939432","title":"Regulation of microRNA expression in vascular smooth muscle by MRTF-A and actin polymerization.","date":"2016","source":"Biochimica et biophysica acta. Molecular cell research","url":"https://pubmed.ncbi.nlm.nih.gov/27939432","citation_count":15,"is_preprint":false},{"pmid":"25446180","id":"PMC_25446180","title":"cAMP-induced actin cytoskeleton remodelling inhibits MKL1-dependent expression of the chemotactic and pro-proliferative factor, CCN1.","date":"2014","source":"Journal of molecular and cellular cardiology","url":"https://pubmed.ncbi.nlm.nih.gov/25446180","citation_count":15,"is_preprint":false},{"pmid":"25585691","id":"PMC_25585691","title":"RNA export factor Ddx19 is required for nuclear import of the SRF coactivator MKL1.","date":"2015","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/25585691","citation_count":15,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":52176,"output_tokens":13630,"usd":0.180489,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":25466,"output_tokens":7434,"usd":0.15659,"stage2_stop_reason":"end_turn"},"total_usd":0.337079,"stage1_batch_id":"msgbatch_01BbTCMyrRPyhtEq6b1MdwCN","stage2_batch_id":"msgbatch_011dEed5bbxYvTAaQWKJevxu","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2002,\n      \"finding\": \"BSAC/MKL1 is a nuclear transcriptional activator that potently activates promoters containing CArG boxes (A+T-rich sequences). Both N-terminal basic and C-terminal proline-rich domains are required for transcriptional activity. Overexpression inhibits TNF-induced caspase activation and cell death, with an intimate correlation between transcriptional activity and antiapoptotic function.\",\n      \"method\": \"Functional cloning, reporter gene assay, domain deletion mutagenesis, overexpression in DKO MEFs\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional cloning with domain mapping and reporter assays in a single lab\",\n      \"pmids\": [\"12019265\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"MKL1 functions as a Rho GTPase-regulated coactivator of SRF to drive a subset (~28 of 150) of serum-inducible immediate-early genes; dominant-negative MKL1 specifically blocks the Rho-MKL pathway without affecting TCF/Elk1-dependent SRF targets.\",\n      \"method\": \"Microarray expression profiling using dominant-negative MKL1 cell line, promoter analysis\",\n      \"journal\": \"BMC molecular biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genome-wide functional screen with DN-MKL1, single lab\",\n      \"pmids\": [\"15329155\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"MKL1 is covalently modified by SUMO-1 at lysine residues K499, K576, and K624. SUMOylation is enhanced by serum stimulation or constitutively active RhoA. Mutation of these three sites strongly enhances MKL1 transcriptional activity without affecting MKL1-SRF interaction, demonstrating that SUMOylation represses MKL1 transcriptional activity.\",\n      \"method\": \"Yeast two-hybrid (identified UBC9), GST pull-down, in vitro SUMOylation reconstitution, site-directed mutagenesis, reporter gene assay\",\n      \"journal\": \"Genes to cells : devoted to molecular & cellular mechanisms\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution of SUMOylation plus mutagenesis of acceptor sites with functional readout, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"16098147\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"MKL1/Mkl1 is required for physiological preparation of the mammary gland during pregnancy and maintenance of lactation. Mkl1 knockout mice exhibit premature involution and impaired expression of SRF-dependent genes in mammary myoepithelial cells, establishing MKL1 as an essential SRF coactivator in this tissue.\",\n      \"method\": \"Gene targeting (Mkl1 knockout mice), histology, gene expression analysis\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean knockout model with specific tissue phenotype and molecular readout\",\n      \"pmids\": [\"16847333\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"MKL1 and MKL2 regulate expression of CArG-containing smooth muscle marker genes (SM alpha-actin, telokin) but not CArG-independent genes. PDGF-BB causes dissociation of MKL factors from CArG-containing promoters via competition with phospho-Elk-1 and subsequent HDAC2/4/5-mediated reduction of acetylated histone H4, repressing SMC marker genes.\",\n      \"method\": \"Gain- and loss-of-function experiments, chromatin immunoprecipitation (ChIP)\",\n      \"journal\": \"American journal of physiology. Cell physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP plus functional assays in a single lab\",\n      \"pmids\": [\"16987998\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"MKL1 directly activates alpha-smooth muscle actin (alpha-SMA) transcription via CArG elements in renal tubular epithelial cells. MKL1 fused to GFP localizes to the nucleus and induces alpha-SMA expression regardless of TGF-β1. siRNA knockdown of MKL1 abolishes TGF-β1-stimulated alpha-SMA expression. ChIP demonstrates that TGF-β1 induces binding of endogenous SRF and MKL1 to the alpha-SMA promoter. MKL1 expression is regulated by the proteasomal ubiquitin pathway.\",\n      \"method\": \"GFP fusion localization, siRNA knockdown, ChIP, reporter gene assay, proteasome inhibitor treatment\",\n      \"journal\": \"American journal of physiology. Renal physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (ChIP, siRNA, localization, reporter), single lab\",\n      \"pmids\": [\"18337547\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"The oncogenic OTT-BSAC/MKL1 fusion protein localizes exclusively to the nucleus (unlike BSAC alone which is predominantly cytoplasmic), aberrantly activates promoters containing YY1-binding sequences, and its formation disrupts the interaction between OTT and HDAC3, collectively perturbing normal transcriptional regulation.\",\n      \"method\": \"Subcellular localization assay, reporter gene assay, co-immunoprecipitation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal protein interaction assays plus localization and functional readout, single lab\",\n      \"pmids\": [\"18667423\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"MKL1 promotes megakaryocytic differentiation by activating SRF. Overexpression of MKL1 increases megakaryocyte number and ploidy; this effect is abrogated by SRF knockdown. Mkl1 knockout mice have reduced platelet counts and reduced megakaryocyte ploidy.\",\n      \"method\": \"MKL1 overexpression in HEL cells and primary CD34+ cells, SRF knockdown, Mkl1 knockout mice\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — epistasis (SRF knockdown abolishes MKL1 effect) plus in vivo knockout, replicated across cell types\",\n      \"pmids\": [\"19136660\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"MKL/MRTF family members are found tethered to monomeric actin in the cytoplasm of hippocampal neurons but translocate to the nucleus upon synaptic activation, where they associate with SRF to regulate expression of structural genes. Mkl expression undergoes learning-associated changes in the hippocampus, contributing to two phases of gene regulation during memory consolidation.\",\n      \"method\": \"Subcellular localization by immunofluorescence, passive avoidance conditioning, gene expression analysis\",\n      \"journal\": \"Cerebral cortex (New York, N.Y. : 1991)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — localization and expression studies linked to a behavioral readout, single lab\",\n      \"pmids\": [\"20016002\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Activin promotes dendritic complexity of cortical neurons in an SRF- and MKL-dependent manner. Activin promotes nuclear export of SCAI (a corepressor of SRF-MKL), and SCAI overexpression blocks activin-induced SRF transcriptional responses and dendritic complexity, identifying an activin-SCAI-MKL signaling axis.\",\n      \"method\": \"Neuronal morphology analysis, SCAI overexpression/knockdown, SRF reporter assay, subcellular localization of SCAI\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — epistasis via SCAI manipulation, multiple readouts, single lab\",\n      \"pmids\": [\"20709749\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"MKL1 and MKL2 play redundant roles in megakaryocyte maturation and platelet formation: double-knockout (MKL1/MKL2) megakaryocytes show more severe thrombocytopenia, ploidy reduction, and cytoskeletal/membrane disorganization than single MKL1 KO. Comparison of gene expression in DKO vs. SRF-deficient megakaryocytes reveals ~4400 differentially regulated genes, indicating both SRF-dependent and SRF-independent activities.\",\n      \"method\": \"Conditional Mkl2 knockout on Mkl1 KO background (DKO), platelet counting, electron microscopy, immunofluorescence, gene expression comparison with SRF KO\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — double knockout mouse model, multiple orthogonal phenotypic assays, genetic epistasis with SRF KO\",\n      \"pmids\": [\"22806889\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"MRTF-A/MAL promotes expression of adhesive genes (integrin α5, plakophilin 2/Pkp2, FHL1) via the actin-MAL-SRF signaling pathway. Elevated MAL impairs migration of non-invasive cells; knockdown of integrin α5, Pkp2, or FHL1 reverses this anti-migratory effect. ChIP shows inducible MAL/SRF recruitment to regulatory elements of the integrin α5 and Pkp2 genes.\",\n      \"method\": \"MAL overexpression and dominant-negative constructs, siRNA knockdown, wound-healing assay, ChIP\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP demonstrating direct promoter occupancy, multiple functional rescue experiments, single lab\",\n      \"pmids\": [\"22223881\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"MRTF-A expression is induced in injured/dedifferentiated vascular smooth muscle cells (VSMCs) and drives pathological vascular remodeling. MRTF-A promotes VSMC migration by activating SRF targets vinculin, MMP-9, and integrin β1. MRTF-A induction in dedifferentiated VSMCs is caused by downregulation of microRNA-1.\",\n      \"method\": \"MRTF-A knockout mice (wire injury and ApoE-/- atherosclerosis models), siRNA knockdown in VSMCs, migration assays, CCG1423 pharmacological inhibition\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple in vivo knockout models with specific molecular targets identified, replicated across two disease models\",\n      \"pmids\": [\"23103763\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Lamin A/C-deficient and Lmna(N195K/N195K) mutant cells have impaired nuclear translocation of MKL1 caused by altered actin dynamics. Ectopic expression of emerin, which is mislocalized in Lmna mutant cells, restores MKL1 nuclear translocation and rescues actin dynamics. This establishes that lamin A/C and emerin regulate MKL1 nucleo-cytoplasmic shuttling through modulation of actin polymerization.\",\n      \"method\": \"Live-cell imaging of MKL1 translocation, ectopic emerin expression in Lmna-/- cells, actin dynamics assays\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean KO models, rescue experiments, live imaging, two orthogonal genetic interventions\",\n      \"pmids\": [\"23644458\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"MKL1 is recruited to the ET-1 promoter by SRF in response to hypoxia in human vascular endothelial cells, where it facilitates histone modifications consistent with transcriptional activation and recruits chromatin remodeling complex components Brg1 and Brm, which are indispensable for ET-1 transactivation.\",\n      \"method\": \"ChIP, dominant-negative MKL1, siRNA knockdown, reporter assay\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP demonstrating direct promoter occupancy plus functional rescue with multiple components, single lab\",\n      \"pmids\": [\"23625963\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"MRTF-A promotes SMYD3-dependent histone methylation on the MYL9 promoter to activate MYL9 transcription and breast cancer cell migration. Co-immunoprecipitation and mutation analysis show that this cooperative transactivation requires the proximal CArG-box binding element of MRTF-A and the HMT activity of SMYD3.\",\n      \"method\": \"Co-IP, siRNA knockdown, reporter gene assay with promoter mutation, cell migration assay, ChIP\",\n      \"journal\": \"Cancer letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus functional mutagenesis, single lab\",\n      \"pmids\": [\"24189459\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Cell shape regulates MRTF-A subcellular localization during TGF-β1-induced EMT: cell spreading promotes nuclear accumulation of MRTF-A, whereas blocking cell spreading prevents MRTF-A nuclear translocation and the myofibroblast phenotype. Overexpression of MRTF-A promotes cytoskeletal protein expression independent of cell shape.\",\n      \"method\": \"Micro-contact printing to control cell shape, pharmacological inhibition of cytoskeletal tension (blebbistatin), MRTF-A overexpression, immunofluorescence\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — localization assay with functional consequence linked to shape, single lab with multiple inhibitors\",\n      \"pmids\": [\"24340092\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Induction of adipocyte differentiation disrupts actin stress fibres via RhoA-ROCK downregulation, causing a rapid increase in monomeric G-actin that binds MKL1 and prevents its nuclear translocation, thereby allowing PPARγ expression and adipogenic differentiation. MKL1 and PPARγ act in a mutually antagonistic manner during adipogenic differentiation.\",\n      \"method\": \"Actin manipulation (cytochalasin D, latrunculin A), MKL1 overexpression/siRNA, PPARγ reporter assay, Co-IP, subcellular fractionation\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal biochemical and genetic approaches, mechanistic model with G-actin binding established, single lab\",\n      \"pmids\": [\"24569594\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Thymosin β4 (Tβ4) induces MRTF-A translocation to the nucleus by binding G-actin, activating SRF and driving CCN1 and CCN2 transcription to promote capillary proliferation and pericyte recruitment, respectively. Loss of MRTF-A/B or CCN1 function abolishes the Tβ4 neovascularization effect.\",\n      \"method\": \"Forced MRTF-A expression, MRTF-A/B knockout mice, hindlimb ischemia model, functional assays, nuclear translocation imaging\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis in knockout mice plus overexpression, multiple in vivo models across species, replicated\",\n      \"pmids\": [\"24910328\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"MRTF-A is recruited to the ET-1 promoter by c-Jun/c-Fos (AP-1) in response to Ang II, where it alters chromatin structure by modulating histone acetylation and H3K4 methylation, driving ET-1 transcription and cardiac hypertrophy. Endothelial-specific MRTF-A silencing phenocopies systemic MRTF-A deletion in Ang II-induced pathological hypertrophy.\",\n      \"method\": \"ChIP, MRTF-A overexpression/depletion, lentiviral endothelial-specific silencing, luciferase reporter, co-IP\",\n      \"journal\": \"Journal of molecular and cellular cardiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP plus cell-specific in vivo genetic intervention plus multiple biochemical assays, single lab\",\n      \"pmids\": [\"25446178\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"MRTF-A and STAT3 physically interact and synergistically activate transcription of migration markers MYL9 and Cyr-61 via CArG box binding, promoting breast cancer cell migration. The RhoA-MRTF-A and JAK-STAT3 pathways cross-talk in this process.\",\n      \"method\": \"Co-IP demonstrating physical MRTF-A/STAT3 interaction, reporter assay, siRNA knockdown, migration assay\",\n      \"journal\": \"Cellular signalling\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — Co-IP plus reporter assay with functional migration readout, single lab\",\n      \"pmids\": [\"25038455\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Loss-of-function homozygous MKL1 mutation in a human patient causes primary immunodeficiency characterized by loss of F-actin content in immune cells, reduced G-actin levels, and downregulation of multiple actin-regulating genes. MKL1-deficient neutrophils display severely impaired migration and nearly abolished phagocytosis, and primary dendritic cells cannot form podosomes. Myeloid cell silencing experiments confirm that F-actin assembly is abrogated through reduced G-actin levels.\",\n      \"method\": \"Patient genetic analysis, flow cytometry (F-actin content), migration assays, phagocytosis assay, siRNA knockdown in myeloid cell lines\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — human loss-of-function genetics confirmed by cellular reconstitution experiments across multiple cell types\",\n      \"pmids\": [\"26224645\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"MKL1 promotes lung cancer cell migration and invasion by epigenetically activating MMP9 transcription. MKL1 recruits ASH2 (a component of the H3K4 methyltransferase complex) to the MMP9 promoter, and MKL1 knockdown eliminates H3K4 methylation at the MMP9 promoter.\",\n      \"method\": \"ChIP, siRNA knockdown, migration/invasion assays, reporter assay\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP showing promoter recruitment and histone modification, functional migration readout, single lab\",\n      \"pmids\": [\"25746000\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"TGF-β induces MKL1 binding to pro-fibrogenic gene promoters. MKL1 promotes the interaction between MKL1 and SMAD3 — each requiring the other for chromatin occupancy. MKL1 recruits a H3K4 methyltransferase complex to fibrogenic promoters, and knockdown of individual complex members reduces SMAD3 binding and portal fibroblast activation.\",\n      \"method\": \"ChIP, Co-IP, siRNA knockdown, bile duct ligation mouse model\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP plus Co-IP with in vivo model, single lab\",\n      \"pmids\": [\"26241940\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Filamin A (FLNA) physically interacts with MKL1 via identified interaction domains. FLNA-MKL1 interaction is required for MKL1 target gene expression and cell migration in primary fibroblasts and cancer cells. LPA-induced RhoA activation promotes endogenous MKL1-FLNA association; actin polymerization inhibitors dissociate the complex. An MKL1 mutant unable to bind FLNA shows impaired cell migration and reduced SRF target gene expression, establishing FLNA as a positive transducer linking F-actin to MKL1-SRF activity.\",\n      \"method\": \"Co-IP, domain mapping, site-directed mutagenesis, reporter assay, migration assay across multiple cell types\",\n      \"journal\": \"Science signaling\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, domain mapping, mutagenesis, and functional migration assay across multiple cell types in single study\",\n      \"pmids\": [\"26554816\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Mkl1 SAP domain-dependent signaling (independent of SRF) mediates aggressive mammary tumor progression following radiotherapy. Application of dynamic strain or matrix stiffness converts predominantly SRF/Mkl1-dependent gene expression to SAP-domain-dependent Mkl1 signaling and promotes SAP-dependent tumor cell migration; tumors expressing Mkl1 lacking the SAP domain exhibit impaired growth and metastasis.\",\n      \"method\": \"Tumor overexpression (full-length vs. SAP-deleted Mkl1), in vivo preirradiated mammary gland model, migration assays, transcript profiling\",\n      \"journal\": \"Molecular oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — domain deletion in vivo model with transcriptomic and functional readouts, single lab\",\n      \"pmids\": [\"25999144\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"MKL1 inhibits cell cycle progression in podocytes via transcriptional activation of p21 through a CArG element in the p21 promoter. MKL1 overexpression decreases S-phase cells; knockdown has the opposite effect. ChIP confirms MKL1 recruitment to the p21 promoter.\",\n      \"method\": \"MKL1 overexpression and siRNA knockdown, cell cycle analysis (flow cytometry), ChIP, PCR array, reporter assay\",\n      \"journal\": \"BMC molecular biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP plus gain/loss of function with cell cycle readout, single lab\",\n      \"pmids\": [\"25888165\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Rho-dependent MRTF-A phosphorylation reflects relief from inhibitory nuclear actin. Multiple serum-induced S/T-P phosphorylation sites are required for transcriptional activation. ERK-mediated S98 phosphorylation inhibits G-actin complex assembly on the RPEL domain, promoting nuclear import. S33 phosphorylation potentiates an autonomous Crm1-dependent N-terminal NES that cooperates with five other NES elements to exclude MRTF-A from the nucleus. Thus phosphorylation plays both positive and negative roles in MRTF-A regulation.\",\n      \"method\": \"Phosphosite mapping (mass spectrometry), site-directed mutagenesis, nuclear localization assays, Crm1 inhibition, in vitro G-actin binding assay\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro biochemistry, site-directed mutagenesis at multiple sites, nuclear localization assays, mass spectrometry-based mapping in a single comprehensive study\",\n      \"pmids\": [\"27304076\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"MRTF-A and STAT3 synergistically recruit DNMT1 to the BRMS1 promoter, causing hypermethylation and transcriptional silencing of BRMS1 to promote breast cancer cell migration. Physical interaction between MRTF-A and STAT3 promotes DNMT1 transactivity by binding to the GAS element in the DNMT1 promoter.\",\n      \"method\": \"Luciferase reporter assay, Co-IP, ChIP, bisulfite sequencing, siRNA knockdown, migration assay\",\n      \"journal\": \"IUBMB life\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus ChIP plus methylation assay, single lab\",\n      \"pmids\": [\"25854163\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"MKL regulates cellular levels of profilin isoforms Pfn1 and Pfn2 indirectly through modulation of STAT1, utilizing MKL's SAP domain function independently of SRF. MKL also influences Pfn1 cellular externalization rather than transcription, and modulates cell migration through Pfn1.\",\n      \"method\": \"Reporter assay, siRNA knockdown, MKL SAP domain mutants, migration assay, cellular fractionation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple assays including domain mutants, single lab\",\n      \"pmids\": [\"28546428\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"p38MAPK/MK2 phosphorylates MRTF-A at Ser351 (Ser312 in human) and Ser371 (Ser333 in human) in a stress-dependent (not mitogen-induced) manner. This was confirmed by in vitro kinase assay, phospho-specific antibodies, MK2/3-deficient cells, and phospho-site mutants. However, these phosphorylations do not detectably affect MRTF-A dimerization, subcellular localization, actin interaction, SRF interaction, SMAD3 interaction, or transactivating potential under the tested conditions.\",\n      \"method\": \"Phosphoproteomic approaches (two independent), in vitro kinase assay, phospho-site mutagenesis, subcellular localization assay, MK2/3 KO cells\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro kinase assay plus mutagenesis, but functional consequences are negative/undetermined\",\n      \"pmids\": [\"27492266\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"MKL1 independently inhibits brown adipogenesis. MKL1 knockdown induces brown adipocyte differentiation and increases PPARγ target gene expression. Co-IP demonstrates that MKL1 physically interacts with PPARγ, suggesting MKL1 exerts its effect by modulating PPARγ activity independently of its SRF-related function.\",\n      \"method\": \"siRNA knockdown, brown adipocyte differentiation assays, Co-IP, UCP1 and thermogenic gene expression\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — Co-IP plus functional differentiation assay, single lab\",\n      \"pmids\": [\"28125644\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"MKL1 is acetylated in vivo by PCAF (lysine acetyltransferase). Pro-inflammatory stimuli (TNF-α, LPS) augment MKL1 acetylation and promote MKL1 binding to NF-κB target promoters. Acetylation at four conserved lysine residues is required for MKL1 trans-activation of NF-κB target genes. Mechanistically, MKL1 acetylation promotes nuclear enrichment, enhances MKL1-NF-κB interaction, and stabilizes MKL1 binding to target promoters.\",\n      \"method\": \"Co-IP (MKL1-PCAF interaction), acetylation assay, site-directed mutagenesis (4 Lys mutant), ChIP, nuclear fractionation, reporter assay\",\n      \"journal\": \"Biochimica et biophysica acta. Gene regulatory mechanisms\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — writer identified (PCAF), mutagenesis of acceptor sites, ChIP for promoter occupancy, multiple orthogonal methods, single lab\",\n      \"pmids\": [\"28571745\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"MKL1 recruits SET1 (H3K4 methyltransferase) and BRG1 (chromatin remodeler) to the MMP2 promoter via NF-κB in response to hypoxia in ovarian cancer cells, coordinating their interaction to alter chromatin structure and activate MMP2 transcription. This promotes cancer cell migration and invasion.\",\n      \"method\": \"ChIP, Co-IP, siRNA knockdown, reporter assay, migration/invasion assay\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP plus Co-IP plus functional assay, single lab\",\n      \"pmids\": [\"28385531\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"WDR1 promotes nuclear import of MRTF-A by affecting expression of the nuclear transport protein importin, enhancing MRTF-A-induced cell migration. MRTF-A in turn promotes miR-206 expression via CArG box in its promoter; miR-206 then inhibits WDR1 and MRTF-A expression, forming a feedback loop regulating breast cancer cell migration.\",\n      \"method\": \"siRNA knockdown, nuclear fractionation, importin expression analysis, reporter assay (CArG box), migration assay\",\n      \"journal\": \"Experimental cell research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — nuclear fractionation plus reporter assay, single lab\",\n      \"pmids\": [\"28822708\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"In drug-resistant basal cell carcinomas, nuclear MKL1 forms a protein complex with SRF and GLI1 near hedgehog target genes, amplifying GLI1 transcriptional activity. Cytoskeletal activation through Rho and mDia (formin) is required for SRF-MKL-driven GLI1 activation and tumor cell viability.\",\n      \"method\": \"Multidimensional genomics, Co-IP (MKL1-SRF-GLI1 complex), Rho/mDia pathway inhibition, nuclear MKL1 staining as biomarker\",\n      \"journal\": \"Nature medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — Co-IP establishing novel protein complex, genomic analysis, pathway epistasis, validated in human tumor specimens\",\n      \"pmids\": [\"29400712\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"HDAC6 co-immunoprecipitates with MRTF-A and deacetylates it; pharmacological inhibition of HDAC6 with tubastatin A increases MRTF-A acetylation and total MRTF-A protein, enhancing SRF transcriptional activity in vascular smooth muscle cells.\",\n      \"method\": \"Co-IP, HDAC6 inhibition (tubastatin A), HDAC6 knockdown, luciferase reporter, in vivo carotid injury model\",\n      \"journal\": \"JACC. Basic to translational science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus functional assays in vitro and in vivo, single lab\",\n      \"pmids\": [\"30623138\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"MRTF-A mediates macrophage ROS production during acute kidney injury by promoting NOX1 transcription. Mechanistically, MRTF-A interacts with the acetyltransferase MYST1 to regulate histone H4K16 acetylation at NOX1/NOX4 gene promoters. Macrophage-specific MRTF-A deletion ameliorates AKI in mice.\",\n      \"method\": \"Macrophage-specific KO, ChIP, Co-IP (MRTF-A-MYST1), in vitro NOX promoter assay, AKI mouse models\",\n      \"journal\": \"Biochimica et biophysica acta. Molecular basis of disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, ChIP, cell-type-specific KO, single lab\",\n      \"pmids\": [\"29908908\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"MKL1 directly binds the CTGF promoter by interacting with SMAD3, activating CTGF transcription in renal tubular epithelial cells. MKL1 mediates interplay between p300 and WDR5 to regulate CTGF transcription. Genetic or pharmacological inhibition of MKL1 reduces renal fibrosis in vivo.\",\n      \"method\": \"ChIP, Co-IP (MKL1-SMAD3-p300-WDR5 interactions), UUO mouse model of fibrosis, siRNA knockdown\",\n      \"journal\": \"Journal of cellular physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP plus multiple Co-IPs, in vivo model, single lab\",\n      \"pmids\": [\"31637729\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"The mRNA export factor Ddx19/Dbp5 is specifically required for nuclear import of MKL1. Ddx19 modulates the conformation of MKL1, affecting its interaction with Importin-β for efficient nuclear import. This effect requires RNA binding activity of Ddx19 but not its helicase or nuclear pore-binding activities.\",\n      \"method\": \"siRNA knockdown, nuclear localization assay, Co-IP (MKL1-Importin-β), domain mutagenesis of Ddx19, rescue experiments\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mechanistic dissection of import pathway with domain mutagenesis and Co-IP, single focused study with multiple orthogonal methods\",\n      \"pmids\": [\"25585691\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"MRTF-A directly binds the Abl1 (c-Abl) promoter via interaction with Sp1 to activate c-Abl transcription. Reciprocally, c-Abl activates ERK, which phosphorylates MRTF-A and promotes its nuclear translocation, forming a positive feedback loop contributing to hepatic stellate cell activation and liver fibrosis.\",\n      \"method\": \"ChIP (MRTF-A binding to Abl1 promoter), Co-IP (MRTF-A-Sp1), pharmacological c-Abl inhibition, nuclear fractionation, MRTF-A KO mice\",\n      \"journal\": \"Frontiers in cell and developmental biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP, Co-IP, and nuclear fractionation, single lab\",\n      \"pmids\": [\"31681772\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"MKL1-actin pathway reduces chromatin accessibility and impedes somatic cell reprogramming to pluripotency. Sustained MKL1 expression yields excessive actin cytoskeleton, decreases nuclear volume, and reduces global chromatin accessibility. This block can be partially bypassed by inhibiting the Sun2-containing LINC complex, linking cytoskeletal tension to chromatin regulation.\",\n      \"method\": \"MKL1 overexpression, ATAC-seq (chromatin accessibility), nuclear volume measurement, LINC complex disruption, reprogramming assays\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genome-wide chromatin accessibility assay plus genetic interventions and rescue experiments, single lab with multiple orthogonal approaches\",\n      \"pmids\": [\"30979898\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"MRTF-A interacts with SRF to bind directly to the EREG promoter and activate EREG transcription in hepatic stellate cells (HSC). EREG stimulation promotes MRTF-A nuclear translocation in HSC, forming a feedforward loop where MRTF-A drives EREG production, and EREG in turn re-activates MRTF-A.\",\n      \"method\": \"ChIP, Co-IP (MRTF-A/SRF), MRTF-A KO mice, nuclear fractionation, siRNA knockdown\",\n      \"journal\": \"Frontiers in cell and developmental biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP and Co-IP supported by KO mice, single lab\",\n      \"pmids\": [\"33520984\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"MKL1 deficiency in a second family with homozygous frameshift mutation causes severe neutrophil actin polymerization defect, strongly reduced motility/chemotactic response, and failure of firm adherence and transendothelial migration under flow. Proteomic and transcriptomic analyses confirm actin and actin-related proteins are downregulated in patient neutrophils. Non-hematopoietic primary fibroblasts show defective myofibroblast differentiation but normal migration, attributed to MKL2 compensation.\",\n      \"method\": \"Patient genetic analysis, proteomic/transcriptomic analysis, actin polymerization assay, migration/chemotaxis assay, transendothelial migration under flow, degranulation assay\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — human loss-of-function genetics confirmed by multi-omics and multiple cellular assays, second independent family confirming first report\",\n      \"pmids\": [\"32128589\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"YAP promotes myofibroblast differentiation in cardiac fibroblasts through TEAD1-driven de novo expression of MRTF-A, which then drives extracellular matrix gene expression. Genetic inhibition of fibroblast YAP attenuates cardiac fibrosis and reduces MRTF-A expression.\",\n      \"method\": \"Cardiac fibroblast-specific YAP knockout, gene expression analysis, fibrosis assessment after myocardial infarction\",\n      \"journal\": \"JACC. Basic to translational science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — cell-type-specific KO with molecular mechanism identified, single lab\",\n      \"pmids\": [\"33015415\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"MRTF-A interacts with TIP60 acetyltransferase to synergistically activate iNOS transcription in macrophages during hypoxia-reoxygenation. MRTF-A directly binds the iNOS promoter; its binding is associated with trimethylated H3K4, acetylated H3K9, H3K27, and H4K16. TIP60 also forms crosstalk with the H3K4 trimethyltransferase complex at this promoter.\",\n      \"method\": \"ChIP (MRTF-A binding to iNOS promoter + histone marks), Co-IP (MRTF-A-TIP60), siRNA knockdown, MRTF-A KO mice\",\n      \"journal\": \"Frontiers in cell and developmental biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP plus Co-IP with in vivo model, single lab\",\n      \"pmids\": [\"32626711\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"TGF-β upregulates MRTF-A expression in non-small-cell lung cancer cells; MRTF-A then interacts with NF-κB/p65 (rather than SRF) to facilitate p65 binding to the PDL1 promoter, activating PD-L1 transcription and promoting immune escape.\",\n      \"method\": \"Co-IP (MRTF-A/NF-κB p65), ChIP (p65 binding to PDL1 promoter), siRNA knockdown, reporter assay, syngraft tumor model\",\n      \"journal\": \"Experimental & molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus ChIP with in vivo model, single lab\",\n      \"pmids\": [\"34548615\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"MKL1 interacts with E2F1 to activate FOXM1 transcription in vascular smooth muscle cells. ROS-induced MKL1 phosphorylation through MK2 is essential for this MKL1-E2F1 interaction and FOXM1 trans-activation. VSMC-specific deletion of MKL1 suppresses neointima formation in mice.\",\n      \"method\": \"VSMC-specific MKL1 KO, Co-IP (MKL1-E2F1), ChIP, siRNA knockdown, MK2 inhibition, ROS assays, neointima model\",\n      \"journal\": \"Redox biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, ChIP, and cell-type-specific KO, single lab\",\n      \"pmids\": [\"36587486\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"In LMNA-mutant muscle cells, ERK1/2-phosphorylated cofilin-1 (pT25-cofilin-1) binds MRTF-A in the cytoplasm, preventing SRF stimulation in the nucleus. MRTF-A/SRF inhibition decreases ATAT1 expression and thus α-tubulin acetylation. In Atat1 KO mice, left ventricular dilation and Cx43 mislocalization are observed. Tubastatin A treatment restores Cx43 localization and cardiac function in Lmna mutant mice.\",\n      \"method\": \"Co-IP (cofilin-1/MRTF-A interaction), cardiomyocytes from LMNA patient-derived iPSCs, Lmna(H222P/H222P) mice, Atat1 KO mice, tubastatin A treatment, cardiac functional assessment\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — Co-IP establishing physical interaction, multiple genetic models (patient-derived cells, two KO mouse lines), pharmacological rescue, multiple orthogonal approaches\",\n      \"pmids\": [\"36550158\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"The lncRNA INKILN physically interacts with MKL1 to stabilize it and reduces MKL1 ubiquitination by protecting the physical interaction between MKL1 and the deubiquitinase USP10. INKILN depletion abolishes the physical interaction between p65 and MKL1 and blocks interleukin-1β-induced nuclear localization of both p65 and MKL1, reducing NF-κB-driven vascular smooth muscle inflammation.\",\n      \"method\": \"RNA-protein interaction assays, Co-IP (INKILN/MKL1/USP10/p65 interactions), MKL1 ubiquitination assay, siRNA knockdown, BAC transgenic mice, NF-κB reporter\",\n      \"journal\": \"Circulation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple RNA-protein and protein-protein interaction assays, in vivo BAC transgenic mouse model, ubiquitination mechanistic readout, single lab\",\n      \"pmids\": [\"37199168\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"MRTF-A interacts with TEAD1 to bind the Zeb1 promoter and activate Zeb1 transcription in renal fibroblasts. Zeb1 in turn represses IRF9 transcription, promoting fibroblast-to-myofibroblast transition. Myofibroblast-specific deletion of MRTF-A ameliorates renal fibrosis.\",\n      \"method\": \"ChIP (MRTF-A/TEAD1 at Zeb1 promoter), Co-IP, siRNA knockdown, Postn-CreERT2 x Mrtfa-flox conditional KO mice, RNA-seq\",\n      \"journal\": \"Experimental & molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP plus Co-IP with cell-type-specific KO, single lab\",\n      \"pmids\": [\"37121967\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Emerin is required for Mkl1 nuclear accumulation and maximal SRF-Mkl1-dependent gene expression in a substrate stiffness-dependent manner in fibroblasts. Emerin is dispensable on more compliant substrates. A constitutively active Mkl1 bypasses the requirement for Emerin.\",\n      \"method\": \"Emerin knockout fibroblasts, nuclear localization assay for Mkl1, luciferase reporter, polyacrylamide gel substrates of defined stiffness, constitutively active Mkl1 rescue\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KO with nuclear localization assay and functional reporter, epistasis with constitutively active Mkl1, single lab\",\n      \"pmids\": [\"28576971\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"S1P-induced RhoA activation leads to nuclear accumulation of MRTF-A in cardiomyocytes. Pharmacological inhibition or siRNA knockdown of MRTF-A significantly diminishes S1P-mediated CCN1 expression, and S1P-induced cardioprotection against simulated ischemia/reperfusion is significantly reduced by MRTF-A inhibition.\",\n      \"method\": \"Nuclear accumulation assay, MRTF-A knockdown/pharmacological inhibition, CCN1 expression assay, simulated I/R apoptosis assay, RhoA manipulation\",\n      \"journal\": \"Journal of molecular and cellular cardiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple pharmacological and genetic interventions, functional cardioprotection readout, single lab\",\n      \"pmids\": [\"25106095\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"MKL1 interacts with AP-1 and SMAD3 to trans-activate CTGF in hepatocytes in response to high glucose treatment, contributing to hepatic stellate cell activation in a non-cell-autonomous manner. Genetic ablation or pharmacological inhibition of MKL1 in hepatocytes abrogates the pro-fibrogenic effect.\",\n      \"method\": \"ChIP (MKL1 binding to CTGF promoter), Co-IP (MKL1-AP-1-SMAD3), conditioned medium experiments, siRNA knockdown, MKL1 KO mice\",\n      \"journal\": \"Biochimica et biophysica acta. Gene regulatory mechanisms\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP plus Co-IP with KO model, single lab\",\n      \"pmids\": [\"30951901\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"MRTF-A/MKL1 is a signal-regulated transcriptional coactivator that is held inactive in the cytoplasm through direct binding of monomeric G-actin to its N-terminal RPEL domain; signals that activate RhoA-driven actin polymerization reduce free G-actin, releasing MRTF-A to translocate to the nucleus (facilitated by Importin-β and the RNA helicase Ddx19), where it binds SRF at CArG-box-containing promoters to drive expression of cytoskeletal, immediate-early, and cell-identity genes. Nuclear accumulation is positively regulated by ERK-mediated S98 phosphorylation (inhibiting G-actin re-assembly), by PCAF-mediated lysine acetylation (which enhances nuclear retention and NF-κB co-complex formation), and by filamin A binding; it is negatively regulated by Crm1-dependent nuclear export (potentiated by S33 phosphorylation), by SUMO-1 modification at K499/K576/K624, and by re-sequestration with G-actin. Beyond SRF, MRTF-A also co-operates with NF-κB/p65, SMAD3, AP-1, STAT3, C/EBPβ, TEAD1, and ETS factors, and recruits chromatin-modifying complexes (PCAF, TIP60, MYST1, SMYD3, SET1, ASH2-H3K4 methyltransferase, BRG1/Brg1-Brm remodelers) to activate target gene transcription. MRTF-A is physiologically required for mammary gland lactation, megakaryocyte/platelet maturation, VSMC identity, cardiomyocyte identity, and immune-cell cytoskeletal function, and its dysregulation drives fibrosis, vascular remodeling, cardiomyopathy, and cancer metastasis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MRTFA (MKL1/MAL/BSAC) is a signal-regulated transcriptional coactivator that couples the state of the actin cytoskeleton to a gene-expression program controlling cell identity, migration, and tissue remodeling, principally by partnering with serum response factor (SRF) at CArG-box promoters [#0, #1, #5]. Its activity is gated by actin dynamics: monomeric G-actin tethers MRTF-A in the cytoplasm, and RhoA-driven actin polymerization (triggered by stimuli such as S1P, thymosin \\u03b24, or cell spreading) depletes free G-actin to permit nuclear translocation, whereas conditions that raise G-actin\\u2014as during adipogenic differentiation\\u2014retain it cytoplasmically and license antagonistic programs such as PPAR\\u03b3-driven differentiation [#16, #17, #18, #52]. Nucleocytoplasmic shuttling is further controlled by an Importin-\\u03b2 import pathway facilitated by the RNA-binding helicase Ddx19 and by WDR1, by Crm1-dependent export, and by the nuclear-envelope proteins lamin A/C and emerin acting through actin dynamics in a substrate-stiffness-dependent manner [#39, #34, #13, #51, #27]. MRTF-A activity is tuned post-translationally: ERK-mediated S98 phosphorylation promotes nuclear import while S33 phosphorylation potentiates nuclear export [#27]; SUMO-1 modification at K499/K576/K624 represses transcriptional output [#2]; PCAF-mediated acetylation enhances nuclear retention and NF-\\u03baB co-complex formation, an acetylation reversed by HDAC6 [#32, #36]; and lncRNA INKILN stabilizes the protein by protecting a USP10 deubiquitination interaction [#49]. Once nuclear, MRTF-A functions as a chromatin-remodeling hub, recruiting H3K4 methyltransferase complexes (ASH2, SET1, WDR5), acetyltransferases (PCAF, TIP60/MYST1, SMYD3, p300) and BRG1/Brm remodelers to target promoters, and cooperating beyond SRF with NF-\\u03baB/p65, SMAD3, AP-1, STAT3, TEAD1, GLI1, E2F1, and Sp1 to drive cytoskeletal, adhesive, pro-fibrotic, and pro-migratory genes [#22, #23, #32, #33, #37, #45, #38, #15]. Genetically, MRTF-A and its paralog MKL2 are required for megakaryocyte/platelet maturation and mammary gland lactation, and human loss-of-function mutations cause a primary immunodeficiency marked by defective F-actin assembly, impaired neutrophil migration, and abolished phagocytosis [#3, #7, #10, #21, #43]. Dysregulated MRTF-A drives pathological vascular remodeling, cardiac hypertrophy and fibrosis, renal and hepatic fibrosis, and cancer cell migration, invasion, and immune escape [#12, #19, #38, #50, #46].\",\n  \"teleology\": [\n    {\n      \"year\": 2002,\n      \"claim\": \"Established MRTFA as a nuclear transcriptional activator acting at CArG-box promoters, defining the domains required for its activity and linking transcriptional output to cell survival.\",\n      \"evidence\": \"Functional cloning, reporter assays, and domain-deletion mutagenesis in DKO MEFs\",\n      \"pmids\": [\"12019265\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Did not identify the upstream signal or partner directing CArG-box selectivity\", \"Anti-apoptotic mechanism left undefined\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Placed MRTFA in the Rho GTPase pathway as a selective coactivator of SRF for a defined subset of immediate-early genes, distinguishing it from the TCF/Elk1 branch.\",\n      \"evidence\": \"Microarray profiling with a dominant-negative MKL1 cell line\",\n      \"pmids\": [\"15329155\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism coupling Rho to MKL1 not resolved\", \"Target gene selectivity determinants unknown\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Identified SUMOylation as a repressive post-translational switch on MRTFA, showing modification at three lysines dampens transcription without disrupting SRF binding.\",\n      \"evidence\": \"Yeast two-hybrid (UBC9), in vitro SUMOylation reconstitution, acceptor-site mutagenesis with reporter readout\",\n      \"pmids\": [\"16098147\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How SUMOylation mechanistically represses transcription unclear\", \"Physiological contexts of SUMO regulation untested\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Demonstrated an essential, non-redundant in vivo requirement for MRTFA as an SRF coactivator in mammary myoepithelial cells and showed it controls smooth-muscle marker genes via CArG elements.\",\n      \"evidence\": \"Mkl1 knockout mice with histology and expression analysis; ChIP and gain/loss-of-function in VSMCs\",\n      \"pmids\": [\"16847333\", \"16987998\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not address paralog (MKL2) compensation\", \"Upstream signal controlling tissue-specific activity not defined\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Showed MRTFA directly drives \\u03b1-SMA via SRF/CArG occupancy downstream of TGF-\\u03b21 and is itself controlled by proteasomal turnover, and revealed an oncogenic fusion that forces nuclear localization and aberrant target activation.\",\n      \"evidence\": \"ChIP, siRNA, GFP-fusion localization, proteasome inhibition; localization and reciprocal Co-IP for OTT-MKL1 fusion\",\n      \"pmids\": [\"18337547\", \"18667423\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Ubiquitin ligase mediating turnover not identified\", \"Generality of fusion mechanism to other cancers untested\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Established MRTFA as a driver of megakaryocyte differentiation and ploidy through SRF, using epistasis to confirm SRF dependence in vivo.\",\n      \"evidence\": \"MKL1 overexpression in HEL and CD34+ cells, SRF knockdown, Mkl1 knockout mice with platelet phenotyping\",\n      \"pmids\": [\"19136660\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"SRF-independent contributions not yet separated\", \"Mechanism of ploidy control unresolved\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Extended actin-gated MRTFA-SRF signaling to neurons, linking synaptic activation and an activin-SCAI corepressor axis to structural gene expression and dendritic complexity.\",\n      \"evidence\": \"Immunofluorescence localization, behavioral conditioning, SCAI manipulation, SRF reporter assays\",\n      \"pmids\": [\"20016002\", \"20709749\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct neuronal target genes not mapped\", \"How SCAI mechanistically represses MKL-SRF unclear\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Resolved paralog redundancy by showing MKL1/MKL2 double knockout produces more severe megakaryocyte and platelet defects, and revealed both SRF-dependent and SRF-independent transcriptional activities; further defined MRTFA control of adhesion/migration genes and pathological VSMC remodeling.\",\n      \"evidence\": \"Conditional Mkl1/Mkl2 DKO with EM and expression comparison to SRF KO; ChIP and rescue in cancer cells; MRTF-A KO injury and atherosclerosis models\",\n      \"pmids\": [\"22806889\", \"22223881\", \"23103763\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular basis of SRF-independent activity not defined\", \"Mechanism by which miR-1 loss induces MRTF-A only partially characterized\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Connected nuclear-envelope architecture (lamin A/C, emerin) and cell-shape/cytoskeletal tension to MRTFA nuclear shuttling via actin dynamics, and revealed MRTFA as a recruiter of chromatin-modifying machinery (Brg1/Brm, SMYD3) at target promoters.\",\n      \"evidence\": \"Live-cell imaging and emerin rescue in Lmna-/- cells; micro-contact printing with blebbistatin; ChIP and Co-IP for chromatin complexes\",\n      \"pmids\": [\"23644458\", \"24340092\", \"23625963\", \"24189459\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How emerin/lamin alter actin dynamics mechanistically incomplete\", \"Generality of each chromatin-modifier recruitment across promoters untested\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Dissected actin-gated import in detail\\u2014G-actin sequestration during adipogenesis blocks MRTFA, while thymosin \\u03b24 and S1P promote import\\u2014and broadened the partner repertoire to STAT3 and AP-1 driving migration and hypertrophy programs.\",\n      \"evidence\": \"Actin manipulation, Co-IP, subcellular fractionation, PPAR\\u03b3 reporters; MRTF-A/B KO ischemia models; STAT3 and AP-1 Co-IP and ChIP\",\n      \"pmids\": [\"24569594\", \"24910328\", \"25446178\", \"25038455\", \"25106095\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry and competition between actin and partner binding unresolved\", \"How partner choice (SRF vs STAT3 vs AP-1) is determined unclear\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Demonstrated a SAP-domain, SRF-independent arm of MRTFA signaling responsive to mechanical strain, established human loss-of-function immunodeficiency from defective F-actin assembly, and added FLNA as a positive F-actin-to-MRTFA transducer plus epigenetic activation of MMP9 and p21.\",\n      \"evidence\": \"SAP-deleted Mkl1 tumor models; patient genetics with cellular reconstitution; FLNA Co-IP/domain mapping/mutagenesis; ChIP for MMP9 and p21\",\n      \"pmids\": [\"25999144\", \"26224645\", \"26554816\", \"25746000\", \"25888165\", \"26241940\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular targets of SAP-domain signaling incompletely defined\", \"How FLNA conformationally transduces F-actin status to MRTFA unresolved\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Provided a comprehensive phosphorylation map showing ERK-S98 promotes import and S33 potentiates Crm1-dependent export, identified stress-induced p38/MK2 sites of uncertain consequence, and revealed PPAR\\u03b3-direct and STAT3-DNMT1 mechanisms plus SAP-dependent profilin control.\",\n      \"evidence\": \"Mass-spec phosphosite mapping, multi-site mutagenesis, Crm1 inhibition, in vitro G-actin binding; MK2/3 KO cells; Co-IP with PPAR\\u03b3 and STAT3; bisulfite sequencing\",\n      \"pmids\": [\"27304076\", \"27492266\", \"28125644\", \"25854163\", \"28546428\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional role of p38/MK2 sites remained undetermined in tested conditions\", \"Kinase responsible for each import/export site not fully assigned\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Established acetylation by PCAF as a positive switch enhancing nuclear retention and NF-\\u03baB co-complex formation, and defined SET1/BRG1 recruitment via NF-\\u03baB and WDR1/importin-mediated import in cancer contexts, with emerin acting in a stiffness-dependent manner.\",\n      \"evidence\": \"Acetylation assays, four-lysine mutant, ChIP, nuclear fractionation; ChIP/Co-IP for SET1-BRG1; nuclear fractionation and reporter for WDR1; emerin KO with stiffness substrates\",\n      \"pmids\": [\"28571745\", \"28385531\", \"28822708\", \"28576971\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Acetyltransferase/deacetylase balance in vivo not quantified\", \"Direct demonstration of importin conformational change incomplete\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Identified HDAC6 as the deacetylase counteracting MRTFA acetylation, placed MRTFA in a SRF-GLI1 hedgehog co-complex driving drug-resistant tumor viability, and showed MYST1-dependent H4K16 acetylation at NOX promoters in macrophage oxidative responses.\",\n      \"evidence\": \"Co-IP and tubastatin A in VSMCs; Co-IP for MKL1-SRF-GLI1 with genomics and pathway inhibition; macrophage-specific KO with ChIP and Co-IP\",\n      \"pmids\": [\"30623138\", \"29400712\", \"29908908\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How nuclear MKL1 selects GLI1 vs SRF targets unresolved\", \"Direct enzymatic kinetics of MRTFA-MYST1 cooperation not measured\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Mechanistically defined the import machinery (Ddx19 modulating MKL1 conformation for Importin-\\u03b2), revealed MRTFA-driven feedforward fibrotic loops (Abl1/Sp1, EREG, CTGF via SMAD3/AP-1/p300/WDR5), and showed sustained MKL1-actin signaling represses chromatin accessibility to block reprogramming.\",\n      \"evidence\": \"Ddx19 domain mutagenesis and Co-IP; ChIP/Co-IP and KO mice for Abl1, EREG, CTGF; ATAC-seq with LINC-complex disruption\",\n      \"pmids\": [\"25585691\", \"31681772\", \"33520984\", \"31637729\", \"30951901\", \"30979898\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How Ddx19 RNA-binding alters MKL1 conformation structurally unknown\", \"Mechanism linking cytoskeletal tension to global chromatin accessibility incompletely defined\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Confirmed human MRTFA immunodeficiency in a second family with multi-omic and functional neutrophil defects (with MKL2 compensation in fibroblasts), placed MRTFA downstream of YAP/TEAD1 in cardiac myofibroblast differentiation, and added TIP60-dependent histone marks at the iNOS promoter.\",\n      \"evidence\": \"Patient genetics with proteomics/transcriptomics and flow-based migration assays; fibroblast-specific YAP KO; ChIP and Co-IP with MRTF-A KO mice\",\n      \"pmids\": [\"32128589\", \"33015415\", \"32626711\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Determinants of MKL2 compensation across cell types unclear\", \"Whether YAP-TEAD1 induction of MRTF-A is direct vs indirect not fully resolved\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Showed MRTFA can act through NF-\\u03baB/p65 (not SRF) to drive PD-L1 and immune escape, and through E2F1 with ROS/MK2-dependent phosphorylation to activate FOXM1 in vascular remodeling.\",\n      \"evidence\": \"Co-IP, ChIP, reporter and syngraft tumor model for PD-L1; VSMC-specific KO, Co-IP, ChIP and MK2 inhibition for FOXM1\",\n      \"pmids\": [\"34548615\", \"36587486\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Switch governing SRF-dependent vs NF-\\u03baB/E2F1-dependent modes unresolved\", \"Single-lab interaction data without reciprocal structural validation\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Linked LMNA-mutant cardiomyopathy to cytoplasmic sequestration of MRTFA by phospho-cofilin-1, with downstream ATAT1/\\u03b1-tubulin acetylation defects and pharmacological rescue, integrating actin/microtubule and nuclear-envelope biology.\",\n      \"evidence\": \"Co-IP, patient-derived iPSC cardiomyocytes, Lmna(H222P) and Atat1 KO mice, tubastatin A rescue with cardiac functional assessment\",\n      \"pmids\": [\"36550158\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Generality of cofilin-1 sequestration beyond LMNA disease unknown\", \"Quantitative contribution of MRTFA-SRF vs other ATAT1 regulators not isolated\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Identified lncRNA INKILN as a stabilizer of MKL1 (protecting USP10 deubiquitination and enabling p65 co-complex formation) and extended the TEAD1 partnership to a Zeb1/IRF9 axis in renal myofibroblast transition.\",\n      \"evidence\": \"RNA-protein and protein-protein interaction assays, ubiquitination assay, BAC transgenic mice; ChIP/Co-IP with myofibroblast-specific MRTF-A KO and RNA-seq\",\n      \"pmids\": [\"37199168\", \"37121967\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of INKILN-MKL1-USP10 protection unknown\", \"How MRTFA partitions between SRF and TEAD1 promoters not defined\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved how MRTFA selects among its many transcription-factor partners (SRF, NF-\\u03baB, SMAD3, STAT3, AP-1, TEAD1, GLI1, E2F1, Sp1) and chromatin-modifier complexes at a given promoter, and how the integrated phosphorylation/acetylation/SUMOylation/ubiquitination code is read out to dictate context-specific outputs.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of MRTFA bound to alternative partners\", \"Quantitative rules for SRF-dependent vs SRF-independent (SAP-domain) signaling undefined\", \"Combinatorial PTM logic governing localization and partner choice unmapped\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [0, 1, 5, 11, 22]},\n      {\"term_id\": \"GO:0003677\", \"supporting_discovery_ids\": [0, 5, 26]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [17, 24, 48]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [32, 35, 46]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0, 5, 13, 27, 39]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [17, 27, 48]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [0, 1, 5, 22]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 17, 24, 52]},\n      {\"term_id\": \"R-HSA-4839726\", \"supporting_discovery_ids\": [14, 22, 23, 32, 41]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [3, 7, 10]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [12, 19, 38, 46, 50]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [21, 43, 32]}\n    ],\n    \"complexes\": [\n      \"MRTF-A/SRF complex\",\n      \"H3K4 methyltransferase complex (SET1/ASH2/WDR5)\",\n      \"MKL1-NF-\\u03baB/p65 co-complex\",\n      \"SRF-MKL1-GLI1 complex\"\n    ],\n    \"partners\": [\n      \"SRF\",\n      \"RELA\",\n      \"SMAD3\",\n      \"STAT3\",\n      \"FLNA\",\n      \"TEAD1\",\n      \"PCAF\",\n      \"DDX19\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"tie","faith_supported":7,"faith_total":7,"faith_pct":100.0}}