{"gene":"MAFK","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":1993,"finding":"MafK (mafK) encodes a nuclear bZIP protein that lacks the amino-terminal acidic transactivation domain present in c-Maf, yet retains a conserved bZIP domain. When overexpressed via retroviral vector, MafK protein localizes predominantly to the nucleus.","method":"cDNA cloning, retroviral overexpression, immunofluorescence/immunostaining with specific antibody, soft-agar colony formation assay","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization experiment with nuclear detection, structural analysis by sequence comparison, single lab with multiple methods","pmids":["8361754"],"is_preprint":false},{"year":1995,"finding":"MafK binds to consensus NF-E2 sites as a homodimer in vitro and represses transcription of NF-E2 site-dependent reporter genes; when co-expressed with p45 (NF-E2 large subunit), MafK confers site-specific DNA-binding activity to p45 and p45 in turn mediates transcriptional activation via its amino-terminal proline-rich domain.","method":"In vitro DNA-binding assay (EMSA), transient transfection reporter assays, cDNA isolation and structural analysis","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — in vitro binding assay combined with transient transfection functional assays, replicated across multiple experimental contexts in the same study","pmids":["7706310"],"is_preprint":false},{"year":1995,"finding":"Conditional overexpression of MafK in murine erythroleukemia cells induced hemoglobin accumulation (terminal erythroid differentiation) and increased DNA-binding activities containing MafK, demonstrating MafK is sufficient to promote the erythroid differentiation program.","method":"Stable transfection with metallothionein-driven MafK, hemoglobin assay, EMSA for DNA-binding activity","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean conditional overexpression with defined differentiation phenotype and direct DNA-binding readout, replicated across multiple clones","pmids":["7638211"],"is_preprint":false},{"year":1996,"finding":"Bach1 and Bach2, novel BTB-bZIP transcription factors, heterodimerize with MafK (identified by yeast two-hybrid screen) and bind NF-E2 sites in vitro. Bach1/MafK and Bach2/MafK heterodimers function as transcriptional repressors in fibroblasts; Bach1/MafK acts as an activator while Bach2/MafK acts as a repressor in erythroid cells.","method":"Yeast two-hybrid screen, in vitro DNA-binding assay (EMSA), transfection reporter assays in fibroblast and erythroid cells","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — yeast two-hybrid identification confirmed by in vitro binding and functional reporter assays across multiple cell types","pmids":["8887638"],"is_preprint":false},{"year":1996,"finding":"MafK expression in mesoderm is driven by a distal promoter (IM), while neuronal expression is directed by a distinct proximal promoter (IN) located ~6 kb 3' to the mesodermal promoter; in neurons, MafK associates with a partner molecule distinct from p45.","method":"Northern blot analysis during murine development, promoter mapping, transgenic mouse reporter assays","journal":"Genes to cells : devoted to molecular & cellular mechanisms","confidence":"High","confidence_rationale":"Tier 2 / Strong — dual-promoter architecture confirmed by transgenic reporter assays in vivo with developmental time-course analysis","pmids":["9140066"],"is_preprint":false},{"year":1997,"finding":"MafK (NF-E2p18) is required for DMSO-induced erythroid differentiation in Friend erythroleukemia cells: overexpression of MafK induced globin transcripts and increased NF-E2 DNA-binding activity, while antisense inhibition of MafK blocked DMSO-induced differentiation and reduced NF-E2 DNA-binding activity.","method":"Stable transfection of sense/antisense constructs, Northern blot for globin transcripts, EMSA for NF-E2 DNA-binding, transient transfection reporter assays","journal":"Leukemia","confidence":"High","confidence_rationale":"Tier 2 / Strong — bidirectional loss- and gain-of-function with multiple orthogonal readouts (differentiation, DNA binding, reporter), single lab","pmids":["9009092"],"is_preprint":false},{"year":1998,"finding":"The core region (nt -67 to -9) of the mafK neuronal IN promoter is sufficient to direct neuron-specific transcription in the ventral spinal cord both in cell transfection assays and in transgenic mice in vivo.","method":"Transient transfection reporter assays, transgenic mouse reporter assays","journal":"Genes to cells : devoted to molecular & cellular mechanisms","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo transgenic confirmation of promoter element, single lab","pmids":["9893024"],"is_preprint":false},{"year":1998,"finding":"Human MAFK gene is located at chromosome 7p22, consists of a conserved bZIP-containing structure, and its gene organization is highly conserved with murine mafK.","method":"Restriction enzyme mapping, Southern blot hybridization, nucleotide sequencing, FISH","journal":"Cytogenetics and cell genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct chromosomal localization by FISH, single lab","pmids":["9763667"],"is_preprint":false},{"year":2000,"finding":"MafG and MafK homodimers bind the NQO1 antioxidant response element (ARE) and repress ARE-mediated expression and antioxidant induction of NQO1 and GST Ya genes; MafK-Nrf2 heterodimers also bind the ARE. Maf-Nrf1 heterodimers failed to bind the NQO1 ARE.","method":"Transient transfection overexpression assays in HepG2 cells, EMSA/supershift assays with NQO1 ARE and nuclear proteins","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — direct DNA-binding (EMSA) combined with functional repression in transfection assays; negative result for Maf-Nrf1 explicitly tested","pmids":["11013233"],"is_preprint":false},{"year":2000,"finding":"Compound mafG/mafK double-null mice survive embryogenesis but die postnatally, and exhibit synthetic phenotypes including severe anemia with abnormal erythrocyte morphology/membrane protein composition, exacerbated thrombocytopenia with proplatelet formation defects, and severe neurological disorders, establishing redundant but essential roles of small Maf proteins in erythropoiesis, megakaryopoiesis, and neuronal function.","method":"Germline targeted null mutations, compound mutant mouse genetic analysis, hematological and histological phenotyping","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — double-knockout genetic epistasis with multiple defined cellular phenotypes across tissues","pmids":["10716933"],"is_preprint":false},{"year":2000,"finding":"A tissue-specific enhancer 3' to the mafK gene (HCEK) directs mafK transcription in both hematopoietic and cardiac muscle cells; two specific GATA consensus motifs within HCEK are required for activity in both tissues, and GATA-1, GATA-4, and GATA-6 each bind these sites with high specificity.","method":"Transgenic mouse reporter assays, deletion/mutation analysis of enhancer, EMSA for GATA factor binding","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — in vivo transgenic functional validation combined with in vitro binding assays and mutagenesis of critical sites","pmids":["10856242"],"is_preprint":false},{"year":2001,"finding":"Transgenic overexpression of MafK specifically in T cells suppresses T cell proliferation and cytokine secretion (IL-2, IL-4); overexpressed MafK forms homodimers that bind to MARE-like sequences in the IL-2 and IL-4 promoters, repressing MARE-dependent transcription.","method":"T cell-specific transgenic mouse model, EMSA for MafK-promoter binding, RT-PCR for cytokine mRNA, immunological phenotyping","journal":"Genes to cells : devoted to molecular & cellular mechanisms","confidence":"High","confidence_rationale":"Tier 2 / Strong — transgenic overexpression with defined phenotype and direct EMSA evidence for MafK binding to target promoter sequences","pmids":["11737266"],"is_preprint":false},{"year":2002,"finding":"MafK is an NGF-responsive immediate early gene in PC12 cells regulated by an atypical PKC isoform (but not MEK, PLCγ, or PI3K); interference with MafK expression (siRNA) or activity (dominant negative) suppresses NGF-promoted neurite outgrowth in PC12 cells and immature telencephalic neurons, identifying MafK as a regulator of neuronal differentiation.","method":"Serial analysis of gene expression (SAGE), Northern blot/Western blot for expression, pharmacological inhibitor studies, siRNA knockdown, dominant-negative overexpression, neurite outgrowth assay","journal":"The Journal of neuroscience : the official journal of the Society for Neuroscience","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal loss-of-function approaches (siRNA + dominant negative) with defined cellular phenotype and pathway dissection by inhibitors","pmids":["12388604"],"is_preprint":false},{"year":2004,"finding":"The Nrf2/MafK heterodimer specifically binds the GST-P enhancer element GPE1 and activates GST-P gene transcription during hepatocarcinogenesis; chromatin immunoprecipitation showed both Nrf2 and MafK occupy GPE1 in pre-neoplastic hepatocytes and hepatoma cells but not normal hepatocytes.","method":"EMSA, DNase I footprinting with wild-type and mutant GPE1, reporter transfection assays, Northern blot, ChIP assays","journal":"The Biochemical journal","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — multiple orthogonal methods including in vitro binding, mutagenesis, reporter assays, and ChIP in relevant cell models","pmids":["14960151"],"is_preprint":false},{"year":2007,"finding":"MafK/NF-E2 p18 knockdown reduces NF-E2 occupancy at the beta-globin locus, decreases H3 acetylation, H3-K4 methylation, and RNA Pol II deposition at the beta-globin gene cluster, and reduces the spatial proximity (looping frequency) between the LCR hypersensitive site HS2 and downstream active beta-globin gene promoters, establishing MafK's role in mediating LCR-gene looping for transcriptional activation.","method":"siRNA knockdown in MEL cells, ChIP assays for NF-E2, histone marks and RNA Pol II, Chromosome Conformation Capture (3C) assay","journal":"The international journal of biochemistry & cell biology","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — multiple orthogonal methods including 3C, ChIP, and knockdown with defined chromatin and transcriptional phenotypes","pmids":["18308612"],"is_preprint":false},{"year":2008,"finding":"NF-κB p65 represses Nrf2-ARE pathway through two mechanisms involving MafK: (1) p65 competitively deprives CBP from Nrf2 via the CH1-KIX domain interaction (dependent on PKA-mediated S276 phosphorylation of p65); (2) p65 facilitates recruitment of HDAC3 corepressor to ARE by promoting HDAC3 interaction with either CBP or MafK, leading to local histone hypoacetylation.","method":"Co-immunoprecipitation, reporter assays, chromatin immunoprecipitation, overexpression and knockdown experiments","journal":"Biochimica et biophysica acta","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP and ChIP evidence for HDAC3-MafK interaction and recruitment, single lab with multiple methods","pmids":["18241676"],"is_preprint":false},{"year":2013,"finding":"TGF-β induces MafK and Bach1 expression; elevated MafK is sufficient to suppress electrophile-inducible HO-1 expression even with nuclear Nrf2 present; siRNA knockdown of MafK and Bach1 abolishes TGF-β-dependent HO-1 suppression; ChIP assays show TGF-β pretreatment increases MafK binding to the HO-1 ARE (E2 site) together with Smads, displacing Nrf2.","method":"siRNA knockdown, overexpression, ChIP assays for Nrf2/Bach1/MafK at HO-1 ARE, RT-PCR/Western blot","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — bidirectional functional experiments (overexpression + siRNA) combined with ChIP evidence for MafK occupancy at target gene, single lab with multiple orthogonal methods","pmids":["23737527"],"is_preprint":false},{"year":2013,"finding":"JDP2 (Jun dimerization protein 2) directly binds the ARE core sequence and associates with both Nrf2 and MafK via bZIP domains, increasing the DNA-binding activity of the Nrf2-MafK complex to ARE and the transcription of ARE-dependent genes; Jdp2-knockout MEFs show impaired Nrf2-MafK-dependent ARE activation and increased intracellular ROS.","method":"ChIP-qPCR, EMSA, ARE-reporter assays, Jdp2 knockout MEFs, ROS measurements","journal":"Cell death & disease","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — in vitro binding (EMSA), ChIP, reporter assays, and knockout mouse-derived cell validation with multiple orthogonal methods","pmids":["24232097"],"is_preprint":false},{"year":2014,"finding":"In zebrafish, the Bach1b-MafK heterodimer represses exocrine zymogen promoters via MARE motifs, while the Nrf2a-MafK heterodimer activates them; heme stimulates exchange of Bach1b for Nrf2a at MafK-occupied MARE sites; ChIP shows MafK binds MARE sites in 5' regulatory regions of zymogen genes.","method":"In vitro luciferase reporter assays, overexpression and morpholino knockdown in zebrafish, ChIP assays","journal":"Disease models & mechanisms","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — in vivo genetic manipulation combined with in vitro reporter assays and ChIP establishing MafK occupancy at target sites","pmids":["24652768"],"is_preprint":false},{"year":2015,"finding":"Compound Mafg-/-:Mafk+/- mice develop progressive lens defects leading to cataract by age 4 months with severely disorganized fiber cells; microarray profiling identifies 97 differentially regulated genes including oxidative stress and sterol synthesis pathway genes, establishing Mafg and Mafk as regulators of non-crystallin cataract-associated genes in lens fiber cells.","method":"Compound null-allele mouse genetics, high-resolution phenotypic characterization, microarray expression profiling, integrative bioinformatics analysis","journal":"Human genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic loss-of-function with defined tissue phenotype and genome-wide target identification, single lab with multiple methods","pmids":["25896808"],"is_preprint":false},{"year":2017,"finding":"MAFK is induced by TGF-β signaling in TNBC cells and promotes epithelial-mesenchymal transition (EMT) and malignant progression; MAFK directly induces expression of the GPNMB gene; knockdown of MAFK suppresses tumor growth and metastasis, while overexpression of MAFK in NMuMG cells induces EMT, tumor formation, and invasion in mice.","method":"Overexpression and knockdown in cell lines and mouse xenograft/orthotopic models, RNA-seq/gene expression analysis to identify GPNMB as direct target, in vivo tumor implantation assays","journal":"Science signaling","confidence":"High","confidence_rationale":"Tier 2 / Strong — bidirectional in vitro and in vivo experiments with defined EMT phenotype and identification of direct transcriptional target GPNMB","pmids":["28400538"],"is_preprint":false},{"year":2020,"finding":"MafK mediates chromatin remodeling to silence IRF8 expression in non-immune cells in a cell-type-specific manner; ChIP-Seq identified three MafK binding regions within the IRF8 locus (-25 kb, -20 kb, and 6th intron); CRISPR-Cas9 deletion of the MafK-intron6 binding region caused accessible chromatin conformation at the IRF8 locus and significantly increased basal and IFN-γ-induced IRF8 expression.","method":"shRNA library screen, ChIP-Seq, lentiviral reporter constructs, CRISPR-Cas9 deletion of binding sites, ATAC-Seq/chromatin accessibility assays","journal":"Journal of molecular biology","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — ChIP-Seq for genome-wide binding combined with CRISPR deletion and chromatin accessibility readout, multiple orthogonal methods","pmids":["32534063"],"is_preprint":false},{"year":2022,"finding":"Mafg-/-:Mafk-/- double knockout embryonic lenses (E16.5) show abnormally multilayered epithelium, abnormal F-actin distribution at the fulcrum region, and misexpression of cytoskeleton/cell cycle/extracellular matrix genes (including Cdk1, Cdkn1c, Camsap1, Col3a1, Epha5, Pxdn), establishing early embryonic roles for Mafg and Mafk in lens fiber cell differentiation.","method":"Double knockout mouse genetics, E-cadherin/nuclear/F-actin immunostaining, RNA-sequencing of E16.5 lenses, RT-qPCR validation","journal":"Frontiers in cell and developmental biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — complete double-KO with defined cellular phenotypes, transcriptomic profiling, and validation by multiple methods","pmids":["36092713"],"is_preprint":false},{"year":2022,"finding":"MafK overexpression in transgenic mice increases susceptibility to Salmonella mucosal infection by promoting epithelial cell apoptosis through rapid caspase-3 cleavage, facilitating Salmonella dissemination and inflammation.","method":"MafK transgenic mouse oral Salmonella infection model, histological analysis, in vitro cell apoptosis assays, caspase-3 activation measurement","journal":"Aging","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — transgenic overexpression with defined phenotype and caspase-3 mechanistic readout, single lab","pmids":["35260530"],"is_preprint":false},{"year":2025,"finding":"The SUMOylation consensus sequence (ψKxE) of MAFK is functionally important: a non-SUMOylatable MAFK mutant shows impaired ability to induce EMT, cellular migration/invasion, tumor and sphere formation, stem-like properties, and drug resistance against doxorubicin; these effects depend on ABCG2 expression.","method":"Non-SUMOylation mimic mutant overexpression, EMT/migration/invasion assays, tumor/sphere formation assays, drug resistance assays, ABCG2 expression analysis","journal":"Cancer science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mutagenesis of PTM site with multiple functional readouts, single lab, abstract-level detail","pmids":["41316921"],"is_preprint":false},{"year":2026,"finding":"MAFK directly binds the AREG promoter region and transcriptionally activates AREG; elevated MAFK-AREG signaling enables NSCLC cells to escape doxorubicin-induced senescence and promotes proliferation.","method":"ChIP assay for MAFK binding at AREG promoter, Western blot/RT-qPCR, senescence-associated β-galactosidase assay, colony formation, flow cytometry","journal":"Oncology letters","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP evidence for direct promoter binding combined with functional cellular phenotype assays, single lab","pmids":["42180617"],"is_preprint":false},{"year":2024,"finding":"MAFK knockdown in macrophages in vivo (using lipidoid nanoparticles in MI mice) significantly improved cardiac function and suppressed fibrosis, and computational analysis identified MAFK as a contact-forming transcription factor at transposable elements; MAFK knockdown decreased chromatin contacts and loops at and between TE sequences.","method":"In vivo macrophage-specific knockdown via lipidoid nanoparticles in MI mouse model, cardiac functional readout; computational pipeline (te_hic) for chromatin contact analysis; knockdown validation of chromatin loop reduction","journal":"bioRxiv","confidence":"Low","confidence_rationale":"Tier 3 / Weak — preprint, in vivo knockdown with cardiac phenotype but chromatin contact role established primarily computationally with limited mechanistic follow-up for MAFK specifically","pmids":[],"is_preprint":true}],"current_model":"MAFK is a small MAF family bZIP transcription factor that functions as a required heterodimeric partner for CNC proteins (p45/NF-E2, Nrf1, Nrf2) and Bach proteins (Bach1, Bach2) at Maf recognition elements (MAREs)/antioxidant response elements (AREs): as a homodimer it represses MARE-dependent transcription; in heterodimers with CNC proteins it enables transcriptional activation of erythroid and cytoprotective genes, while heterodimers with Bach proteins are repressive; MAFK is required for NF-E2-dependent β-globin locus looping, mediates TGF-β-induced repression of HO-1 by competing with Nrf2 at AREs, regulates chromatin architecture at target loci including IRF8, is regulated by GATA factors (hematopoietic/cardiac), atypical PKC (neuronal, downstream of NGF), and Wnt1 (osteosarcoma), and its SUMOylation consensus sequence is important for MAFK-induced EMT and tumorigenic functions including upregulation of GPNMB and AREG."},"narrative":{"mechanistic_narrative":"MAFK is a small MAF family bZIP transcription factor that operates as an obligate dimerization module: a nuclear protein retaining a conserved bZIP domain but lacking the acidic transactivation domain of large Mafs, so its transcriptional output is dictated by its dimer partner [PMID:8361754]. As a homodimer it binds NF-E2/MARE/ARE sites and represses MARE-dependent transcription, including at the IL-2 and IL-4 promoters and at antioxidant-response genes such as NQO1 and GST Ya [PMID:7706310, PMID:11013233, PMID:11737266]. Conferring DNA-binding to CNC partners, MAFK heterodimerizes with p45/NF-E2 and Nrf2 to enable transcriptional activation — driving erythroid differentiation and globin induction [PMID:7638211, PMID:9009092], activating the GST-P enhancer during hepatocarcinogenesis [PMID:14960151], and, at the β-globin locus, mediating NF-E2 occupancy, active histone marks, RNA Pol II loading, and LCR-to-promoter chromatin looping [PMID:18308612]. Its partnership with the BTB-bZIP Bach1/Bach2 proteins instead yields context-dependent repressive complexes at MARE sites, with heme-driven exchange between Bach and Nrf2 partners switching target genes between repressed and activated states [PMID:8887638, PMID:24652768]. MAFK couples extracellular signals to this transcriptional logic: it is a NGF-responsive immediate-early gene controlled by atypical PKC that drives neurite outgrowth [PMID:12388604], and TGF-β induces MAFK to displace Nrf2 from the HO-1 ARE and repress cytoprotective HO-1 expression [PMID:23737527]. Genetically, MAFK acts redundantly with MAFG — compound Mafg/Mafk mutant mice display anemia, thrombocytopenia, neurological defects, and progressive lens/cataract phenotypes — establishing essential roles in erythropoiesis, megakaryopoiesis, neuronal function, and lens fiber differentiation [PMID:10716933, PMID:25896808, PMID:36092713]. In cancer, TGF-β-induced MAFK promotes epithelial-mesenchymal transition and malignant progression by directly activating GPNMB and AREG, with its SUMOylation consensus sequence required for EMT, stemness, and drug-resistance functions [PMID:28400538, PMID:41316921, PMID:42180617]. Tissue-restricted expression of MAFK is itself controlled by dual mesodermal/neuronal promoters and a GATA-dependent hematopoietic/cardiac enhancer [PMID:9140066, PMID:10856242].","teleology":[{"year":1993,"claim":"Established that MafK is a nuclear bZIP protein lacking a transactivation domain, framing it as a partner-dependent factor rather than an autonomous activator.","evidence":"cDNA cloning, sequence comparison, and immunofluorescence of retrovirally overexpressed protein","pmids":["8361754"],"confidence":"Medium","gaps":["Did not identify physiological dimer partners","No direct DNA target defined"]},{"year":1995,"claim":"Showed MafK binds NF-E2 sites as a repressive homodimer but confers site-specific DNA binding to p45, which supplies the activation function — defining the homodimer-repressor/heterodimer-activator paradigm.","evidence":"EMSA and transient transfection reporter assays with p45 co-expression","pmids":["7706310"],"confidence":"High","gaps":["In vitro binding only for the homodimer repression step","Endogenous target genes not yet defined"]},{"year":1995,"claim":"Demonstrated MafK is sufficient and required to drive terminal erythroid differentiation, linking the factor to a defined cellular program.","evidence":"Conditional/antisense overexpression in murine erythroleukemia cells with hemoglobin and EMSA readouts","pmids":["7638211","9009092"],"confidence":"High","gaps":["Did not resolve which heterodimeric partner mediates the differentiation effect at endogenous loci"]},{"year":1996,"claim":"Identified Bach1/Bach2 as MafK partners, extending the dimer repertoire and showing that partner identity and cell type determine activation versus repression.","evidence":"Yeast two-hybrid screen, EMSA, and reporter assays in fibroblast and erythroid cells","pmids":["8887638"],"confidence":"High","gaps":["Did not define the signal that selects Bach versus CNC partners","No endogenous target loci mapped"]},{"year":1996,"claim":"Resolved that MafK expression is governed by distinct mesodermal and neuronal promoters and that neuronal MafK uses a non-p45 partner, indicating tissue-specific regulatory logic.","evidence":"Northern blot developmental profiling, promoter mapping, and transgenic reporter assays","pmids":["9140066","9893024"],"confidence":"High","gaps":["Neuronal dimer partner not identified","Upstream regulators of each promoter unknown"]},{"year":2000,"claim":"Connected MafK to antioxidant-response transcription, showing homodimers repress ARE genes (NQO1, GST Ya) while Nrf2-MafK heterodimers bind the ARE.","evidence":"EMSA/supershift and transfection assays in HepG2 cells, including a negative result for Maf-Nrf1","pmids":["11013233"],"confidence":"High","gaps":["Did not test endogenous ARE occupancy by ChIP","Activation by Nrf2-MafK shown only as binding"]},{"year":2000,"claim":"Genetically established that small Mafs are redundantly essential in vivo, with Mafg/Mafk double-null mice showing anemia, thrombocytopenia, and neurological defects.","evidence":"Compound germline knockout mouse genetics with hematological and histological phenotyping","pmids":["10716933"],"confidence":"High","gaps":["Cannot separate MafK-specific from MafG-specific functions","Molecular targets driving phenotypes not defined"]},{"year":2000,"claim":"Defined how MafK expression is targeted to hematopoietic and cardiac tissue through a GATA-dependent enhancer, linking lineage transcription factors to MafK levels.","evidence":"Transgenic reporter assays, enhancer mutagenesis, and GATA-factor EMSA","pmids":["10856242"],"confidence":"High","gaps":["Did not address regulation in other MafK-expressing tissues"]},{"year":2002,"claim":"Placed MafK downstream of NGF/atypical PKC signaling as an immediate-early effector of neurite outgrowth, coupling extracellular cues to MafK induction.","evidence":"SAGE, pharmacological pathway dissection, siRNA, and dominant-negative neurite assays in PC12 and telencephalic neurons","pmids":["12388604"],"confidence":"High","gaps":["Transcriptional targets in neurons not identified","Dimer partner mediating neurite effect unknown"]},{"year":2004,"claim":"Provided in vivo chromatin evidence that Nrf2-MafK activates GST-P during hepatocarcinogenesis, occupying GPE1 selectively in pre-neoplastic and tumor cells.","evidence":"EMSA, DNase I footprinting, reporter assays, and ChIP in hepatocytes and hepatoma cells","pmids":["14960151"],"confidence":"High","gaps":["Did not establish what restricts GPE1 occupancy to transformed cells"]},{"year":2008,"claim":"Mechanistically linked MafK to chromatin architecture, showing it is required for NF-E2 occupancy, active histone marks, Pol II loading, and LCR-promoter looping at the β-globin locus.","evidence":"siRNA knockdown with ChIP and 3C in MEL cells","pmids":["18308612"],"confidence":"High","gaps":["Did not define the looping factors recruited via MafK","Generalizability to other loci untested at the time"]},{"year":2008,"claim":"Showed MafK can be co-opted into corepressor recruitment, with NF-κB p65 promoting HDAC3 association at the ARE partly through MafK.","evidence":"Co-IP, ChIP, and reporter assays with overexpression/knockdown","pmids":["18241676"],"confidence":"Medium","gaps":["MafK-HDAC3 interaction shown by Co-IP without reciprocal/structural validation","Direct versus indirect recruitment not resolved"]},{"year":2013,"claim":"Defined a signal-driven partner-switch mechanism in which TGF-β induces MafK to displace Nrf2 at the HO-1 ARE and repress a cytoprotective gene.","evidence":"siRNA, overexpression, and ChIP at the HO-1 ARE with Smad co-occupancy","pmids":["23737527"],"confidence":"High","gaps":["Did not establish whether MafK acts as homodimer or Bach heterodimer at HO-1"]},{"year":2013,"claim":"Identified JDP2 as a positive cofactor that binds the ARE and the Nrf2-MafK complex to enhance ARE binding and activation, modulating cellular ROS.","evidence":"ChIP-qPCR, EMSA, reporter assays, and Jdp2-knockout MEFs","pmids":["24232097"],"confidence":"High","gaps":["Structural basis of the JDP2-MafK-Nrf2 ternary complex not defined"]},{"year":2014,"claim":"Generalized the Bach/Nrf2 partner-switch to exocrine zymogen genes and showed heme triggers the Bach1b-for-Nrf2a exchange at MafK-occupied MARE sites.","evidence":"Reporter assays, zebrafish overexpression/morpholino, and ChIP","pmids":["24652768"],"confidence":"High","gaps":["Did not determine whether MafK remains constitutively bound during partner exchange in mammals"]},{"year":2015,"claim":"Extended small-Maf function to the lens, showing Mafg/Mafk dosage controls oxidative-stress and sterol-synthesis genes whose dysregulation causes cataract.","evidence":"Compound Mafg-/-:Mafk+/- mouse genetics with microarray profiling","pmids":["25896808"],"confidence":"High","gaps":["Direct MafK target genes in lens not validated by ChIP"]},{"year":2017,"claim":"Established an oncogenic role: TGF-β-induced MAFK drives EMT and metastasis by directly activating GPNMB.","evidence":"Bidirectional overexpression/knockdown in TNBC cells and mouse xenograft/orthotopic models with RNA-seq target identification","pmids":["28400538"],"confidence":"High","gaps":["Dimer partner driving GPNMB activation not defined","Whether MAFK acts as activator independent of CNC partners unclear"]},{"year":2020,"claim":"Showed MafK enforces cell-type-specific silencing of IRF8 via chromatin remodeling, with genome-wide binding mapped and a causal intronic site identified.","evidence":"shRNA screen, ChIP-Seq, CRISPR deletion of binding sites, and ATAC-Seq","pmids":["32534063"],"confidence":"High","gaps":["Repressive partner/corepressor at the IRF8 locus not identified"]},{"year":2022,"claim":"Refined the lens role to early embryonic fiber-cell differentiation, with double-null lenses showing cytoskeletal and cell-cycle gene misexpression.","evidence":"Mafg-/-:Mafk-/- mouse genetics, immunostaining, and RNA-seq of E16.5 lenses","pmids":["36092713"],"confidence":"High","gaps":["Direct versus indirect regulation of cytoskeletal/ECM genes not resolved"]},{"year":2022,"claim":"Linked MafK overexpression to epithelial apoptosis and increased Salmonella susceptibility, implicating it in mucosal cell death.","evidence":"MafK transgenic mouse infection model with caspase-3 readouts and in vitro apoptosis assays","pmids":["35260530"],"confidence":"Medium","gaps":["Direct transcriptional targets mediating apoptosis not identified","Single-lab overexpression model"]},{"year":2025,"claim":"Identified MAFK SUMOylation as a functional requirement for its EMT, stemness, and ABCG2-dependent drug-resistance activities.","evidence":"Non-SUMOylatable mutant overexpression with EMT, sphere-formation, and doxorubicin-resistance assays","pmids":["41316921"],"confidence":"Medium","gaps":["SUMO E3 ligase and modification site not biochemically validated","Abstract-level detail, single lab"]},{"year":2026,"claim":"Showed MAFK directly activates AREG to enable escape from doxorubicin-induced senescence in NSCLC, extending its oncogenic target repertoire.","evidence":"ChIP at the AREG promoter with senescence, colony-formation, and flow-cytometry assays","pmids":["42180617"],"confidence":"Medium","gaps":["Dimer partner at AREG promoter undefined","Single-lab study"]},{"year":null,"claim":"It remains unresolved how MAFK switches between repressive (homodimer/Bach) and activating (CNC) modes at a given locus in a signal- and tissue-specific manner, and whether its reported activating oncogenic roles (GPNMB, AREG, EMT) reflect a canonical heterodimer or a distinct mechanism.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural model of MAFK dimer/DNA complexes in the corpus","Mechanism selecting partner identity per locus undefined","Activating partner for oncogenic targets not identified"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[1,3,8,13,16,20,25]},{"term_id":"GO:0003677","term_label":"DNA binding","supporting_discovery_ids":[1,8,11,13,18,21]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[1,3,17]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0]},{"term_id":"GO:0000228","term_label":"nuclear chromosome","supporting_discovery_ids":[14,21]}],"pathway":[{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[1,3,8,13]},{"term_id":"R-HSA-4839726","term_label":"Chromatin organization","supporting_discovery_ids":[14,21]},{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[8,16,17]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[20,25]}],"complexes":["Nrf2-MafK heterodimer","p45/NF-E2-MafK heterodimer","Bach1/Bach2-MafK heterodimer"],"partners":["NFE2","NFE2L2","BACH1","BACH2","JDP2","HDAC3","RELA"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O60675","full_name":"Transcription factor MafK","aliases":["Erythroid transcription factor NF-E2 p18 subunit"],"length_aa":156,"mass_kda":17.5,"function":"Since they lack a putative transactivation domain, the small Mafs behave as transcriptional repressors when they dimerize among themselves (PubMed:9150357). However, they act as transcriptional activators by dimerizing with other (usually larger) basic-zipper proteins, such as NFE2, NFE2L1/NRF1, NFE2L2/NRF2 and NFE2L3/NRF3, and recruiting them to specific DNA-binding sites (PubMed:8932385, PubMed:9150357). Small Maf proteins heterodimerize with Fos and may act as competitive repressors of the NF-E2 transcription factor (PubMed:9150357)","subcellular_location":"Nucleus","url":"https://www.uniprot.org/uniprotkb/O60675/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/MAFK","classification":"Not Classified","n_dependent_lines":29,"n_total_lines":1208,"dependency_fraction":0.024006622516556293},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/MAFK","total_profiled":1310},"omim":[{"mim_id":"605394","title":"BTB AND CNC HOMOLOGY 2; BACH2","url":"https://www.omim.org/entry/605394"},{"mim_id":"604135","title":"NUCLEAR FACTOR ERYTHROID 2-LIKE 3; NFE2L3","url":"https://www.omim.org/entry/604135"},{"mim_id":"602751","title":"BTB AND CNC HOMOLOGY 1; BACH1","url":"https://www.omim.org/entry/602751"},{"mim_id":"602020","title":"MAF bZIP TRANSCRIPTION FACTOR G; MAFG","url":"https://www.omim.org/entry/602020"},{"mim_id":"601637","title":"CYTOCHROME P450, FAMILY 51, SUBFAMILY A, POLYPEPTIDE 1; CYP51A1","url":"https://www.omim.org/entry/601637"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Enhanced","locations":[{"location":"Nucleoplasm","reliability":"Enhanced"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/MAFK"},"hgnc":{"alias_symbol":["P18","NFE2U"],"prev_symbol":[]},"alphafold":{"accession":"O60675","domains":[{"cath_id":"1.20.5.170","chopping":"27-124","consensus_level":"medium","plddt":96.8121,"start":27,"end":124}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O60675","model_url":"https://alphafold.ebi.ac.uk/files/AF-O60675-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O60675-F1-predicted_aligned_error_v6.png","plddt_mean":83.25},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MAFK","jax_strain_url":"https://www.jax.org/strain/search?query=MAFK"},"sequence":{"accession":"O60675","fasta_url":"https://rest.uniprot.org/uniprotkb/O60675.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O60675/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O60675"}},"corpus_meta":[{"pmid":"18241676","id":"PMC_18241676","title":"NF-kappaB/p65 antagonizes 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proliferation.","date":"2015","source":"Genetics and molecular research : GMR","url":"https://pubmed.ncbi.nlm.nih.gov/26214410","citation_count":11,"is_preprint":false},{"pmid":"20233453","id":"PMC_20233453","title":"Akt regulates the expression of MafK, synaptotagmin I, and syntenin-1, which play roles in neuronal function.","date":"2010","source":"Journal of biomedical science","url":"https://pubmed.ncbi.nlm.nih.gov/20233453","citation_count":11,"is_preprint":false},{"pmid":"9893024","id":"PMC_9893024","title":"A core region of the mafK gene IN promoter directs neurone-specific transcription in vivo.","date":"1998","source":"Genes to cells : devoted to molecular & cellular mechanisms","url":"https://pubmed.ncbi.nlm.nih.gov/9893024","citation_count":10,"is_preprint":false},{"pmid":"16780794","id":"PMC_16780794","title":"MafK overexpression in pancreatic beta-cells caused impairment of glucose-stimulated insulin secretion.","date":"2006","source":"Biochemical and biophysical research 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Mediates Chromatin Remodeling to Silence IRF8 Expression in Non-immune Cells in a Cell Type-SpecificManner.","date":"2020","source":"Journal of molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/32534063","citation_count":2,"is_preprint":false},{"pmid":"22293672","id":"PMC_22293672","title":"A novel diabetes mellitus mouse model, MAFA-deficient and beta cell-specific MAFK-overexpressing hybrid transgenic mice, developed severe diabetic nephropathy and improved with TCV-116 (candesartan cilexetil) treatment.","date":"2012","source":"Experimental animals","url":"https://pubmed.ncbi.nlm.nih.gov/22293672","citation_count":2,"is_preprint":false},{"pmid":"41316921","id":"PMC_41316921","title":"Importance of SUMOylation Consensus Sequence of MAFK in Regulating EMT, Tumor Growth, Stemness, and Drug Resistance.","date":"2025","source":"Cancer 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that lacks the amino-terminal acidic transactivation domain present in c-Maf, yet retains a conserved bZIP domain. When overexpressed via retroviral vector, MafK protein localizes predominantly to the nucleus.\",\n      \"method\": \"cDNA cloning, retroviral overexpression, immunofluorescence/immunostaining with specific antibody, soft-agar colony formation assay\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization experiment with nuclear detection, structural analysis by sequence comparison, single lab with multiple methods\",\n      \"pmids\": [\"8361754\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"MafK binds to consensus NF-E2 sites as a homodimer in vitro and represses transcription of NF-E2 site-dependent reporter genes; when co-expressed with p45 (NF-E2 large subunit), MafK confers site-specific DNA-binding activity to p45 and p45 in turn mediates transcriptional activation via its amino-terminal proline-rich domain.\",\n      \"method\": \"In vitro DNA-binding assay (EMSA), transient transfection reporter assays, cDNA isolation and structural analysis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — in vitro binding assay combined with transient transfection functional assays, replicated across multiple experimental contexts in the same study\",\n      \"pmids\": [\"7706310\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"Conditional overexpression of MafK in murine erythroleukemia cells induced hemoglobin accumulation (terminal erythroid differentiation) and increased DNA-binding activities containing MafK, demonstrating MafK is sufficient to promote the erythroid differentiation program.\",\n      \"method\": \"Stable transfection with metallothionein-driven MafK, hemoglobin assay, EMSA for DNA-binding activity\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean conditional overexpression with defined differentiation phenotype and direct DNA-binding readout, replicated across multiple clones\",\n      \"pmids\": [\"7638211\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"Bach1 and Bach2, novel BTB-bZIP transcription factors, heterodimerize with MafK (identified by yeast two-hybrid screen) and bind NF-E2 sites in vitro. Bach1/MafK and Bach2/MafK heterodimers function as transcriptional repressors in fibroblasts; Bach1/MafK acts as an activator while Bach2/MafK acts as a repressor in erythroid cells.\",\n      \"method\": \"Yeast two-hybrid screen, in vitro DNA-binding assay (EMSA), transfection reporter assays in fibroblast and erythroid cells\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — yeast two-hybrid identification confirmed by in vitro binding and functional reporter assays across multiple cell types\",\n      \"pmids\": [\"8887638\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"MafK expression in mesoderm is driven by a distal promoter (IM), while neuronal expression is directed by a distinct proximal promoter (IN) located ~6 kb 3' to the mesodermal promoter; in neurons, MafK associates with a partner molecule distinct from p45.\",\n      \"method\": \"Northern blot analysis during murine development, promoter mapping, transgenic mouse reporter assays\",\n      \"journal\": \"Genes to cells : devoted to molecular & cellular mechanisms\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — dual-promoter architecture confirmed by transgenic reporter assays in vivo with developmental time-course analysis\",\n      \"pmids\": [\"9140066\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"MafK (NF-E2p18) is required for DMSO-induced erythroid differentiation in Friend erythroleukemia cells: overexpression of MafK induced globin transcripts and increased NF-E2 DNA-binding activity, while antisense inhibition of MafK blocked DMSO-induced differentiation and reduced NF-E2 DNA-binding activity.\",\n      \"method\": \"Stable transfection of sense/antisense constructs, Northern blot for globin transcripts, EMSA for NF-E2 DNA-binding, transient transfection reporter assays\",\n      \"journal\": \"Leukemia\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — bidirectional loss- and gain-of-function with multiple orthogonal readouts (differentiation, DNA binding, reporter), single lab\",\n      \"pmids\": [\"9009092\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"The core region (nt -67 to -9) of the mafK neuronal IN promoter is sufficient to direct neuron-specific transcription in the ventral spinal cord both in cell transfection assays and in transgenic mice in vivo.\",\n      \"method\": \"Transient transfection reporter assays, transgenic mouse reporter assays\",\n      \"journal\": \"Genes to cells : devoted to molecular & cellular mechanisms\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo transgenic confirmation of promoter element, single lab\",\n      \"pmids\": [\"9893024\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"Human MAFK gene is located at chromosome 7p22, consists of a conserved bZIP-containing structure, and its gene organization is highly conserved with murine mafK.\",\n      \"method\": \"Restriction enzyme mapping, Southern blot hybridization, nucleotide sequencing, FISH\",\n      \"journal\": \"Cytogenetics and cell genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct chromosomal localization by FISH, single lab\",\n      \"pmids\": [\"9763667\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"MafG and MafK homodimers bind the NQO1 antioxidant response element (ARE) and repress ARE-mediated expression and antioxidant induction of NQO1 and GST Ya genes; MafK-Nrf2 heterodimers also bind the ARE. Maf-Nrf1 heterodimers failed to bind the NQO1 ARE.\",\n      \"method\": \"Transient transfection overexpression assays in HepG2 cells, EMSA/supershift assays with NQO1 ARE and nuclear proteins\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — direct DNA-binding (EMSA) combined with functional repression in transfection assays; negative result for Maf-Nrf1 explicitly tested\",\n      \"pmids\": [\"11013233\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Compound mafG/mafK double-null mice survive embryogenesis but die postnatally, and exhibit synthetic phenotypes including severe anemia with abnormal erythrocyte morphology/membrane protein composition, exacerbated thrombocytopenia with proplatelet formation defects, and severe neurological disorders, establishing redundant but essential roles of small Maf proteins in erythropoiesis, megakaryopoiesis, and neuronal function.\",\n      \"method\": \"Germline targeted null mutations, compound mutant mouse genetic analysis, hematological and histological phenotyping\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — double-knockout genetic epistasis with multiple defined cellular phenotypes across tissues\",\n      \"pmids\": [\"10716933\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"A tissue-specific enhancer 3' to the mafK gene (HCEK) directs mafK transcription in both hematopoietic and cardiac muscle cells; two specific GATA consensus motifs within HCEK are required for activity in both tissues, and GATA-1, GATA-4, and GATA-6 each bind these sites with high specificity.\",\n      \"method\": \"Transgenic mouse reporter assays, deletion/mutation analysis of enhancer, EMSA for GATA factor binding\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — in vivo transgenic functional validation combined with in vitro binding assays and mutagenesis of critical sites\",\n      \"pmids\": [\"10856242\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"Transgenic overexpression of MafK specifically in T cells suppresses T cell proliferation and cytokine secretion (IL-2, IL-4); overexpressed MafK forms homodimers that bind to MARE-like sequences in the IL-2 and IL-4 promoters, repressing MARE-dependent transcription.\",\n      \"method\": \"T cell-specific transgenic mouse model, EMSA for MafK-promoter binding, RT-PCR for cytokine mRNA, immunological phenotyping\",\n      \"journal\": \"Genes to cells : devoted to molecular & cellular mechanisms\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — transgenic overexpression with defined phenotype and direct EMSA evidence for MafK binding to target promoter sequences\",\n      \"pmids\": [\"11737266\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"MafK is an NGF-responsive immediate early gene in PC12 cells regulated by an atypical PKC isoform (but not MEK, PLCγ, or PI3K); interference with MafK expression (siRNA) or activity (dominant negative) suppresses NGF-promoted neurite outgrowth in PC12 cells and immature telencephalic neurons, identifying MafK as a regulator of neuronal differentiation.\",\n      \"method\": \"Serial analysis of gene expression (SAGE), Northern blot/Western blot for expression, pharmacological inhibitor studies, siRNA knockdown, dominant-negative overexpression, neurite outgrowth assay\",\n      \"journal\": \"The Journal of neuroscience : the official journal of the Society for Neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal loss-of-function approaches (siRNA + dominant negative) with defined cellular phenotype and pathway dissection by inhibitors\",\n      \"pmids\": [\"12388604\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"The Nrf2/MafK heterodimer specifically binds the GST-P enhancer element GPE1 and activates GST-P gene transcription during hepatocarcinogenesis; chromatin immunoprecipitation showed both Nrf2 and MafK occupy GPE1 in pre-neoplastic hepatocytes and hepatoma cells but not normal hepatocytes.\",\n      \"method\": \"EMSA, DNase I footprinting with wild-type and mutant GPE1, reporter transfection assays, Northern blot, ChIP assays\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — multiple orthogonal methods including in vitro binding, mutagenesis, reporter assays, and ChIP in relevant cell models\",\n      \"pmids\": [\"14960151\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"MafK/NF-E2 p18 knockdown reduces NF-E2 occupancy at the beta-globin locus, decreases H3 acetylation, H3-K4 methylation, and RNA Pol II deposition at the beta-globin gene cluster, and reduces the spatial proximity (looping frequency) between the LCR hypersensitive site HS2 and downstream active beta-globin gene promoters, establishing MafK's role in mediating LCR-gene looping for transcriptional activation.\",\n      \"method\": \"siRNA knockdown in MEL cells, ChIP assays for NF-E2, histone marks and RNA Pol II, Chromosome Conformation Capture (3C) assay\",\n      \"journal\": \"The international journal of biochemistry & cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — multiple orthogonal methods including 3C, ChIP, and knockdown with defined chromatin and transcriptional phenotypes\",\n      \"pmids\": [\"18308612\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"NF-κB p65 represses Nrf2-ARE pathway through two mechanisms involving MafK: (1) p65 competitively deprives CBP from Nrf2 via the CH1-KIX domain interaction (dependent on PKA-mediated S276 phosphorylation of p65); (2) p65 facilitates recruitment of HDAC3 corepressor to ARE by promoting HDAC3 interaction with either CBP or MafK, leading to local histone hypoacetylation.\",\n      \"method\": \"Co-immunoprecipitation, reporter assays, chromatin immunoprecipitation, overexpression and knockdown experiments\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP and ChIP evidence for HDAC3-MafK interaction and recruitment, single lab with multiple methods\",\n      \"pmids\": [\"18241676\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"TGF-β induces MafK and Bach1 expression; elevated MafK is sufficient to suppress electrophile-inducible HO-1 expression even with nuclear Nrf2 present; siRNA knockdown of MafK and Bach1 abolishes TGF-β-dependent HO-1 suppression; ChIP assays show TGF-β pretreatment increases MafK binding to the HO-1 ARE (E2 site) together with Smads, displacing Nrf2.\",\n      \"method\": \"siRNA knockdown, overexpression, ChIP assays for Nrf2/Bach1/MafK at HO-1 ARE, RT-PCR/Western blot\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — bidirectional functional experiments (overexpression + siRNA) combined with ChIP evidence for MafK occupancy at target gene, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"23737527\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"JDP2 (Jun dimerization protein 2) directly binds the ARE core sequence and associates with both Nrf2 and MafK via bZIP domains, increasing the DNA-binding activity of the Nrf2-MafK complex to ARE and the transcription of ARE-dependent genes; Jdp2-knockout MEFs show impaired Nrf2-MafK-dependent ARE activation and increased intracellular ROS.\",\n      \"method\": \"ChIP-qPCR, EMSA, ARE-reporter assays, Jdp2 knockout MEFs, ROS measurements\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — in vitro binding (EMSA), ChIP, reporter assays, and knockout mouse-derived cell validation with multiple orthogonal methods\",\n      \"pmids\": [\"24232097\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"In zebrafish, the Bach1b-MafK heterodimer represses exocrine zymogen promoters via MARE motifs, while the Nrf2a-MafK heterodimer activates them; heme stimulates exchange of Bach1b for Nrf2a at MafK-occupied MARE sites; ChIP shows MafK binds MARE sites in 5' regulatory regions of zymogen genes.\",\n      \"method\": \"In vitro luciferase reporter assays, overexpression and morpholino knockdown in zebrafish, ChIP assays\",\n      \"journal\": \"Disease models & mechanisms\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — in vivo genetic manipulation combined with in vitro reporter assays and ChIP establishing MafK occupancy at target sites\",\n      \"pmids\": [\"24652768\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Compound Mafg-/-:Mafk+/- mice develop progressive lens defects leading to cataract by age 4 months with severely disorganized fiber cells; microarray profiling identifies 97 differentially regulated genes including oxidative stress and sterol synthesis pathway genes, establishing Mafg and Mafk as regulators of non-crystallin cataract-associated genes in lens fiber cells.\",\n      \"method\": \"Compound null-allele mouse genetics, high-resolution phenotypic characterization, microarray expression profiling, integrative bioinformatics analysis\",\n      \"journal\": \"Human genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic loss-of-function with defined tissue phenotype and genome-wide target identification, single lab with multiple methods\",\n      \"pmids\": [\"25896808\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"MAFK is induced by TGF-β signaling in TNBC cells and promotes epithelial-mesenchymal transition (EMT) and malignant progression; MAFK directly induces expression of the GPNMB gene; knockdown of MAFK suppresses tumor growth and metastasis, while overexpression of MAFK in NMuMG cells induces EMT, tumor formation, and invasion in mice.\",\n      \"method\": \"Overexpression and knockdown in cell lines and mouse xenograft/orthotopic models, RNA-seq/gene expression analysis to identify GPNMB as direct target, in vivo tumor implantation assays\",\n      \"journal\": \"Science signaling\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — bidirectional in vitro and in vivo experiments with defined EMT phenotype and identification of direct transcriptional target GPNMB\",\n      \"pmids\": [\"28400538\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"MafK mediates chromatin remodeling to silence IRF8 expression in non-immune cells in a cell-type-specific manner; ChIP-Seq identified three MafK binding regions within the IRF8 locus (-25 kb, -20 kb, and 6th intron); CRISPR-Cas9 deletion of the MafK-intron6 binding region caused accessible chromatin conformation at the IRF8 locus and significantly increased basal and IFN-γ-induced IRF8 expression.\",\n      \"method\": \"shRNA library screen, ChIP-Seq, lentiviral reporter constructs, CRISPR-Cas9 deletion of binding sites, ATAC-Seq/chromatin accessibility assays\",\n      \"journal\": \"Journal of molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — ChIP-Seq for genome-wide binding combined with CRISPR deletion and chromatin accessibility readout, multiple orthogonal methods\",\n      \"pmids\": [\"32534063\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Mafg-/-:Mafk-/- double knockout embryonic lenses (E16.5) show abnormally multilayered epithelium, abnormal F-actin distribution at the fulcrum region, and misexpression of cytoskeleton/cell cycle/extracellular matrix genes (including Cdk1, Cdkn1c, Camsap1, Col3a1, Epha5, Pxdn), establishing early embryonic roles for Mafg and Mafk in lens fiber cell differentiation.\",\n      \"method\": \"Double knockout mouse genetics, E-cadherin/nuclear/F-actin immunostaining, RNA-sequencing of E16.5 lenses, RT-qPCR validation\",\n      \"journal\": \"Frontiers in cell and developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — complete double-KO with defined cellular phenotypes, transcriptomic profiling, and validation by multiple methods\",\n      \"pmids\": [\"36092713\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"MafK overexpression in transgenic mice increases susceptibility to Salmonella mucosal infection by promoting epithelial cell apoptosis through rapid caspase-3 cleavage, facilitating Salmonella dissemination and inflammation.\",\n      \"method\": \"MafK transgenic mouse oral Salmonella infection model, histological analysis, in vitro cell apoptosis assays, caspase-3 activation measurement\",\n      \"journal\": \"Aging\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — transgenic overexpression with defined phenotype and caspase-3 mechanistic readout, single lab\",\n      \"pmids\": [\"35260530\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"The SUMOylation consensus sequence (ψKxE) of MAFK is functionally important: a non-SUMOylatable MAFK mutant shows impaired ability to induce EMT, cellular migration/invasion, tumor and sphere formation, stem-like properties, and drug resistance against doxorubicin; these effects depend on ABCG2 expression.\",\n      \"method\": \"Non-SUMOylation mimic mutant overexpression, EMT/migration/invasion assays, tumor/sphere formation assays, drug resistance assays, ABCG2 expression analysis\",\n      \"journal\": \"Cancer science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis of PTM site with multiple functional readouts, single lab, abstract-level detail\",\n      \"pmids\": [\"41316921\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"MAFK directly binds the AREG promoter region and transcriptionally activates AREG; elevated MAFK-AREG signaling enables NSCLC cells to escape doxorubicin-induced senescence and promotes proliferation.\",\n      \"method\": \"ChIP assay for MAFK binding at AREG promoter, Western blot/RT-qPCR, senescence-associated β-galactosidase assay, colony formation, flow cytometry\",\n      \"journal\": \"Oncology letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP evidence for direct promoter binding combined with functional cellular phenotype assays, single lab\",\n      \"pmids\": [\"42180617\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"MAFK knockdown in macrophages in vivo (using lipidoid nanoparticles in MI mice) significantly improved cardiac function and suppressed fibrosis, and computational analysis identified MAFK as a contact-forming transcription factor at transposable elements; MAFK knockdown decreased chromatin contacts and loops at and between TE sequences.\",\n      \"method\": \"In vivo macrophage-specific knockdown via lipidoid nanoparticles in MI mouse model, cardiac functional readout; computational pipeline (te_hic) for chromatin contact analysis; knockdown validation of chromatin loop reduction\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — preprint, in vivo knockdown with cardiac phenotype but chromatin contact role established primarily computationally with limited mechanistic follow-up for MAFK specifically\",\n      \"pmids\": [],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"MAFK is a small MAF family bZIP transcription factor that functions as a required heterodimeric partner for CNC proteins (p45/NF-E2, Nrf1, Nrf2) and Bach proteins (Bach1, Bach2) at Maf recognition elements (MAREs)/antioxidant response elements (AREs): as a homodimer it represses MARE-dependent transcription; in heterodimers with CNC proteins it enables transcriptional activation of erythroid and cytoprotective genes, while heterodimers with Bach proteins are repressive; MAFK is required for NF-E2-dependent β-globin locus looping, mediates TGF-β-induced repression of HO-1 by competing with Nrf2 at AREs, regulates chromatin architecture at target loci including IRF8, is regulated by GATA factors (hematopoietic/cardiac), atypical PKC (neuronal, downstream of NGF), and Wnt1 (osteosarcoma), and its SUMOylation consensus sequence is important for MAFK-induced EMT and tumorigenic functions including upregulation of GPNMB and AREG.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MAFK is a small MAF family bZIP transcription factor that operates as an obligate dimerization module: a nuclear protein retaining a conserved bZIP domain but lacking the acidic transactivation domain of large Mafs, so its transcriptional output is dictated by its dimer partner [#0]. As a homodimer it binds NF-E2/MARE/ARE sites and represses MARE-dependent transcription, including at the IL-2 and IL-4 promoters and at antioxidant-response genes such as NQO1 and GST Ya [#1, #8, #11]. Conferring DNA-binding to CNC partners, MAFK heterodimerizes with p45/NF-E2 and Nrf2 to enable transcriptional activation — driving erythroid differentiation and globin induction [#2, #5], activating the GST-P enhancer during hepatocarcinogenesis [#13], and, at the β-globin locus, mediating NF-E2 occupancy, active histone marks, RNA Pol II loading, and LCR-to-promoter chromatin looping [#14]. Its partnership with the BTB-bZIP Bach1/Bach2 proteins instead yields context-dependent repressive complexes at MARE sites, with heme-driven exchange between Bach and Nrf2 partners switching target genes between repressed and activated states [#3, #18]. MAFK couples extracellular signals to this transcriptional logic: it is a NGF-responsive immediate-early gene controlled by atypical PKC that drives neurite outgrowth [#12], and TGF-β induces MAFK to displace Nrf2 from the HO-1 ARE and repress cytoprotective HO-1 expression [#16]. Genetically, MAFK acts redundantly with MAFG — compound Mafg/Mafk mutant mice display anemia, thrombocytopenia, neurological defects, and progressive lens/cataract phenotypes — establishing essential roles in erythropoiesis, megakaryopoiesis, neuronal function, and lens fiber differentiation [#9, #19, #22]. In cancer, TGF-β-induced MAFK promotes epithelial-mesenchymal transition and malignant progression by directly activating GPNMB and AREG, with its SUMOylation consensus sequence required for EMT, stemness, and drug-resistance functions [#20, #24, #25]. Tissue-restricted expression of MAFK is itself controlled by dual mesodermal/neuronal promoters and a GATA-dependent hematopoietic/cardiac enhancer [#4, #10].\",\n  \"teleology\": [\n    {\n      \"year\": 1993,\n      \"claim\": \"Established that MafK is a nuclear bZIP protein lacking a transactivation domain, framing it as a partner-dependent factor rather than an autonomous activator.\",\n      \"evidence\": \"cDNA cloning, sequence comparison, and immunofluorescence of retrovirally overexpressed protein\",\n      \"pmids\": [\"8361754\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Did not identify physiological dimer partners\", \"No direct DNA target defined\"]\n    },\n    {\n      \"year\": 1995,\n      \"claim\": \"Showed MafK binds NF-E2 sites as a repressive homodimer but confers site-specific DNA binding to p45, which supplies the activation function — defining the homodimer-repressor/heterodimer-activator paradigm.\",\n      \"evidence\": \"EMSA and transient transfection reporter assays with p45 co-expression\",\n      \"pmids\": [\"7706310\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vitro binding only for the homodimer repression step\", \"Endogenous target genes not yet defined\"]\n    },\n    {\n      \"year\": 1995,\n      \"claim\": \"Demonstrated MafK is sufficient and required to drive terminal erythroid differentiation, linking the factor to a defined cellular program.\",\n      \"evidence\": \"Conditional/antisense overexpression in murine erythroleukemia cells with hemoglobin and EMSA readouts\",\n      \"pmids\": [\"7638211\", \"9009092\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve which heterodimeric partner mediates the differentiation effect at endogenous loci\"]\n    },\n    {\n      \"year\": 1996,\n      \"claim\": \"Identified Bach1/Bach2 as MafK partners, extending the dimer repertoire and showing that partner identity and cell type determine activation versus repression.\",\n      \"evidence\": \"Yeast two-hybrid screen, EMSA, and reporter assays in fibroblast and erythroid cells\",\n      \"pmids\": [\"8887638\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the signal that selects Bach versus CNC partners\", \"No endogenous target loci mapped\"]\n    },\n    {\n      \"year\": 1996,\n      \"claim\": \"Resolved that MafK expression is governed by distinct mesodermal and neuronal promoters and that neuronal MafK uses a non-p45 partner, indicating tissue-specific regulatory logic.\",\n      \"evidence\": \"Northern blot developmental profiling, promoter mapping, and transgenic reporter assays\",\n      \"pmids\": [\"9140066\", \"9893024\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Neuronal dimer partner not identified\", \"Upstream regulators of each promoter unknown\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Connected MafK to antioxidant-response transcription, showing homodimers repress ARE genes (NQO1, GST Ya) while Nrf2-MafK heterodimers bind the ARE.\",\n      \"evidence\": \"EMSA/supershift and transfection assays in HepG2 cells, including a negative result for Maf-Nrf1\",\n      \"pmids\": [\"11013233\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not test endogenous ARE occupancy by ChIP\", \"Activation by Nrf2-MafK shown only as binding\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Genetically established that small Mafs are redundantly essential in vivo, with Mafg/Mafk double-null mice showing anemia, thrombocytopenia, and neurological defects.\",\n      \"evidence\": \"Compound germline knockout mouse genetics with hematological and histological phenotyping\",\n      \"pmids\": [\"10716933\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cannot separate MafK-specific from MafG-specific functions\", \"Molecular targets driving phenotypes not defined\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Defined how MafK expression is targeted to hematopoietic and cardiac tissue through a GATA-dependent enhancer, linking lineage transcription factors to MafK levels.\",\n      \"evidence\": \"Transgenic reporter assays, enhancer mutagenesis, and GATA-factor EMSA\",\n      \"pmids\": [\"10856242\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not address regulation in other MafK-expressing tissues\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Placed MafK downstream of NGF/atypical PKC signaling as an immediate-early effector of neurite outgrowth, coupling extracellular cues to MafK induction.\",\n      \"evidence\": \"SAGE, pharmacological pathway dissection, siRNA, and dominant-negative neurite assays in PC12 and telencephalic neurons\",\n      \"pmids\": [\"12388604\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Transcriptional targets in neurons not identified\", \"Dimer partner mediating neurite effect unknown\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Provided in vivo chromatin evidence that Nrf2-MafK activates GST-P during hepatocarcinogenesis, occupying GPE1 selectively in pre-neoplastic and tumor cells.\",\n      \"evidence\": \"EMSA, DNase I footprinting, reporter assays, and ChIP in hepatocytes and hepatoma cells\",\n      \"pmids\": [\"14960151\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish what restricts GPE1 occupancy to transformed cells\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Mechanistically linked MafK to chromatin architecture, showing it is required for NF-E2 occupancy, active histone marks, Pol II loading, and LCR-promoter looping at the β-globin locus.\",\n      \"evidence\": \"siRNA knockdown with ChIP and 3C in MEL cells\",\n      \"pmids\": [\"18308612\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the looping factors recruited via MafK\", \"Generalizability to other loci untested at the time\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Showed MafK can be co-opted into corepressor recruitment, with NF-κB p65 promoting HDAC3 association at the ARE partly through MafK.\",\n      \"evidence\": \"Co-IP, ChIP, and reporter assays with overexpression/knockdown\",\n      \"pmids\": [\"18241676\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"MafK-HDAC3 interaction shown by Co-IP without reciprocal/structural validation\", \"Direct versus indirect recruitment not resolved\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Defined a signal-driven partner-switch mechanism in which TGF-β induces MafK to displace Nrf2 at the HO-1 ARE and repress a cytoprotective gene.\",\n      \"evidence\": \"siRNA, overexpression, and ChIP at the HO-1 ARE with Smad co-occupancy\",\n      \"pmids\": [\"23737527\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish whether MafK acts as homodimer or Bach heterodimer at HO-1\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Identified JDP2 as a positive cofactor that binds the ARE and the Nrf2-MafK complex to enhance ARE binding and activation, modulating cellular ROS.\",\n      \"evidence\": \"ChIP-qPCR, EMSA, reporter assays, and Jdp2-knockout MEFs\",\n      \"pmids\": [\"24232097\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of the JDP2-MafK-Nrf2 ternary complex not defined\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Generalized the Bach/Nrf2 partner-switch to exocrine zymogen genes and showed heme triggers the Bach1b-for-Nrf2a exchange at MafK-occupied MARE sites.\",\n      \"evidence\": \"Reporter assays, zebrafish overexpression/morpholino, and ChIP\",\n      \"pmids\": [\"24652768\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not determine whether MafK remains constitutively bound during partner exchange in mammals\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Extended small-Maf function to the lens, showing Mafg/Mafk dosage controls oxidative-stress and sterol-synthesis genes whose dysregulation causes cataract.\",\n      \"evidence\": \"Compound Mafg-/-:Mafk+/- mouse genetics with microarray profiling\",\n      \"pmids\": [\"25896808\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct MafK target genes in lens not validated by ChIP\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Established an oncogenic role: TGF-β-induced MAFK drives EMT and metastasis by directly activating GPNMB.\",\n      \"evidence\": \"Bidirectional overexpression/knockdown in TNBC cells and mouse xenograft/orthotopic models with RNA-seq target identification\",\n      \"pmids\": [\"28400538\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Dimer partner driving GPNMB activation not defined\", \"Whether MAFK acts as activator independent of CNC partners unclear\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Showed MafK enforces cell-type-specific silencing of IRF8 via chromatin remodeling, with genome-wide binding mapped and a causal intronic site identified.\",\n      \"evidence\": \"shRNA screen, ChIP-Seq, CRISPR deletion of binding sites, and ATAC-Seq\",\n      \"pmids\": [\"32534063\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Repressive partner/corepressor at the IRF8 locus not identified\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Refined the lens role to early embryonic fiber-cell differentiation, with double-null lenses showing cytoskeletal and cell-cycle gene misexpression.\",\n      \"evidence\": \"Mafg-/-:Mafk-/- mouse genetics, immunostaining, and RNA-seq of E16.5 lenses\",\n      \"pmids\": [\"36092713\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct versus indirect regulation of cytoskeletal/ECM genes not resolved\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Linked MafK overexpression to epithelial apoptosis and increased Salmonella susceptibility, implicating it in mucosal cell death.\",\n      \"evidence\": \"MafK transgenic mouse infection model with caspase-3 readouts and in vitro apoptosis assays\",\n      \"pmids\": [\"35260530\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct transcriptional targets mediating apoptosis not identified\", \"Single-lab overexpression model\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Identified MAFK SUMOylation as a functional requirement for its EMT, stemness, and ABCG2-dependent drug-resistance activities.\",\n      \"evidence\": \"Non-SUMOylatable mutant overexpression with EMT, sphere-formation, and doxorubicin-resistance assays\",\n      \"pmids\": [\"41316921\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"SUMO E3 ligase and modification site not biochemically validated\", \"Abstract-level detail, single lab\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Showed MAFK directly activates AREG to enable escape from doxorubicin-induced senescence in NSCLC, extending its oncogenic target repertoire.\",\n      \"evidence\": \"ChIP at the AREG promoter with senescence, colony-formation, and flow-cytometry assays\",\n      \"pmids\": [\"42180617\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Dimer partner at AREG promoter undefined\", \"Single-lab study\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved how MAFK switches between repressive (homodimer/Bach) and activating (CNC) modes at a given locus in a signal- and tissue-specific manner, and whether its reported activating oncogenic roles (GPNMB, AREG, EMT) reflect a canonical heterodimer or a distinct mechanism.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structural model of MAFK dimer/DNA complexes in the corpus\", \"Mechanism selecting partner identity per locus undefined\", \"Activating partner for oncogenic targets not identified\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [1, 3, 8, 13, 16, 20, 25]},\n      {\"term_id\": \"GO:0003677\", \"supporting_discovery_ids\": [1, 8, 11, 13, 18, 21]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [1, 3, 17]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0000228\", \"supporting_discovery_ids\": [14, 21]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [1, 3, 8, 13]},\n      {\"term_id\": \"R-HSA-4839726\", \"supporting_discovery_ids\": [14, 21]},\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [8, 16, 17]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [20, 25]}\n    ],\n    \"complexes\": [\"Nrf2-MafK heterodimer\", \"p45/NF-E2-MafK heterodimer\", \"Bach1/Bach2-MafK heterodimer\"],\n    \"partners\": [\"NFE2\", \"NFE2L2\", \"BACH1\", \"BACH2\", \"JDP2\", \"HDAC3\", \"RELA\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":8,"faith_total":8,"faith_pct":100.0}}