{"gene":"MED28","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":2004,"finding":"MED28 (magicin) physically interacts with the NF2 tumor suppressor merlin in vitro and in vivo, colocalizes with merlin beneath the plasma membrane, and associates with the actin cytoskeleton as shown by cofractionation, immunofluorescence, and electron microscopy. MED28 also binds the adaptor protein Grb2 via Grb2-binding motifs in its sequence, and merlin can form a ternary complex with MED28 and Grb2.","method":"Co-immunoprecipitation, affinity binding, blot overlay, immunofluorescence microscopy, electron microscopy, subcellular fractionation","journal":"Oncogene","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (Co-IP, pulldown, blot overlay, EM, fractionation) in a single study establishing direct binding partners and localization","pmids":["15467741"],"is_preprint":false},{"year":2006,"finding":"MED28 (magicin) is phosphorylated by Fyn tyrosine kinase in vitro. Lck and Src also interact with MED28. Upon CD3 stimulation in Jurkat T cells, MED28 is phosphorylated by Lck; phosphorylation is absent in Lck-deficient J.CaM1.6 cells. Site-directed mutagenesis identified Y64 as the phosphorylation site, creating an SH2-Grb2 binding motif.","method":"Yeast two-hybrid, in vitro kinase assay, site-directed mutagenesis, co-immunoprecipitation, stimulation with anti-CD3 antibody","journal":"Biochemical and biophysical research communications","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro kinase assay with mutagenesis identifying exact phosphorylation site, combined with cell-based epistasis using Lck-deficient line","pmids":["16899217"],"is_preprint":false},{"year":2007,"finding":"MED28 (magicin) was independently identified as a subunit of the mammalian Mediator complex. Knockdown of Med28 in NIH3T3 cells induced smooth muscle cell (SMC) differentiation gene expression, while overexpression repressed it. Med28 functions as a repressor of SMC differentiation together with Mediator head module subunits Med6, Med8, and Med18, acting as a scaffolding protein that maintains stability of this head module subcomplex.","method":"siRNA knockdown, overexpression, gene expression analysis, multipotent mesenchymal precursor transdifferentiation assay","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean KD and OE with defined cellular phenotype and pathway placement within Mediator head module, single lab","pmids":["17848560"],"is_preprint":false},{"year":2005,"finding":"EG-1 (MED28) overexpression stimulates cellular proliferation in vitro and in vivo (xenograft), and co-immunoprecipitation demonstrated an association between EG-1 and c-Src. Overexpression of EG-1 correlated with activation of ERK1/2, JNK, and p38 MAPK kinases.","method":"Transfection/overexpression, siRNA knockdown, proliferation assay, xenograft tumor model, co-immunoprecipitation, immunoblotting","journal":"Cancer research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP demonstrating Src association, functional proliferation assay in vitro and in vivo, single lab","pmids":["16024617"],"is_preprint":false},{"year":2006,"finding":"EG-1 (MED28) overexpression activates c-Src signaling and binds to other Src family members. EG-1 also shows interactions with multiple SH3- and WW-domain-containing signaling molecules, though EG-1 was found not to be a direct Src substrate.","method":"Overexpression, immunoprecipitation, immunoblotting for Src activation","journal":"International journal of oncology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single Co-IP/pulldown approach, single lab, negative result for direct phosphorylation noted","pmids":["16964398"],"is_preprint":false},{"year":2012,"finding":"MED28 regulates cellular migration and invasion in human breast cancer cells in a MEK1-dependent manner. Suppression of MED28 reduced MMP2 and MEK1 expression and blocked migration/invasion; overexpression enhanced them. Dominant-negative MEK1, MEK1 siRNA, and MEK1 inhibitors all blocked MED28-induced MMP2 activation and migration. Ectopic MEK1 rescued MED28-knockdown invasion phenotype, and exogenous MMP2 rescued invasion upon MED28 or MEK1 knockdown.","method":"siRNA knockdown, overexpression, dominant-negative construct, MEK1 inhibitors, migration/invasion assays, epistasis rescue experiments","journal":"Journal of cellular physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — epistasis established by multiple genetic and pharmacological rescue experiments, single lab","pmids":["22495818"],"is_preprint":false},{"year":2011,"finding":"MED28 overexpression increases EGF-induced cellular migration in MDA-MB-231 breast cancer cells, and its effect on migration occurs presumably through the EGFR/PI3K signaling pathway. Resveratrol suppressed EGF-mediated migration and reduced MED28 and MMP-9 expression.","method":"Overexpression, siRNA knockdown, migration assay, immunoblotting","journal":"Journal of agricultural and food chemistry","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, functional migration assay with overexpression/knockdown but PI3K pathway placement inferred rather than directly demonstrated","pmids":["21942447"],"is_preprint":false},{"year":2015,"finding":"Med28 knockout mice die at the peri-implantation stage due to loss of pluripotency of the inner cell mass, accompanied by reduced expression of pluripotency transcription factors Oct4 and Nanog. Overexpression of Med28 in mouse embryonic fibroblasts enhances reprogramming efficiency to iPSCs. Cre-mediated inactivation of Med28 in iPSCs causes cell death, and heterozygous loss leads to differentiation into trophectoderm and primitive endoderm lineages.","method":"Knockout mouse model, Cre-mediated conditional inactivation, iPSC reprogramming assay, gene expression analysis","journal":"PloS one","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo knockout with defined developmental phenotype, multiple genetic models (full KO, conditional KO, heterozygous) with consistent results","pmids":["26445504"],"is_preprint":false},{"year":2016,"finding":"MED28 modulates epithelial-mesenchymal transition (EMT) through NFκB in human breast cancer cells. Suppression of MED28 reduced p-NFκB/p65, Snail, and mesenchymal markers, and attenuated EMT induced by Adriamycin. Overexpression of MED28 enhanced EMT markers.","method":"siRNA knockdown, overexpression, Adriamycin-induced EMT model, immunoblotting for EMT markers and p-NFκB/p65","journal":"Journal of cellular physiology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single method set, NFκB pathway placement by correlation without direct mechanistic proof","pmids":["27662245"],"is_preprint":false},{"year":2015,"finding":"Suppression of MED28 in colorectal cancer cells reduced expression of cyclin D1, c-Myc, and nuclear β-catenin, and increased expression of E-cadherin and HBP1 (a negative regulator of Wnt/β-catenin signaling). MED28 knockdown increased HBP1 promoter reporter activity while overexpression decreased it, placing MED28 as a repressor of HBP1 in the Wnt/β-catenin pathway.","method":"siRNA knockdown, overexpression, luciferase reporter assay, immunoblotting","journal":"Journal of cellular physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — luciferase reporter assay combined with KD/OE and expression analysis establishing pathway placement, single lab","pmids":["26660958"],"is_preprint":false},{"year":2017,"finding":"MED28 directly interacts with ZNF224 (a Krüppel-associated-box zinc finger protein) in the nucleus; the KRAB domain of ZNF224 interacts with the MED domain of MED28. Overexpression of MED28 inhibited camptothecin-induced degradation of ZNF224, stabilizing it and resulting in increased colony formation in MCF-7 cells.","method":"Co-immunoprecipitation, surface plasmon resonance, bimolecular fluorescence complementation, overexpression, colony formation assay","journal":"Oncology letters","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct binding confirmed by orthogonal methods (Co-IP + SPR + BiFC), functional consequence demonstrated, single lab","pmids":["29435049"],"is_preprint":false},{"year":2018,"finding":"MED28 interacts with FOXM1 in NSCLC cells; both proteins mutually affect each other's expression levels and subcellular localization. Elevated MED28 and FOXM1 together increase MMP2 expression and enhance cell migration and invasion. MED28 siRNA-mediated MMP2 suppression was rescued by inducible constitutively active FOXM1, restoring migration and invasion.","method":"Co-immunoprecipitation, siRNA knockdown, doxycycline-inducible FOXM1 overexpression system, migration/invasion assays, immunoblotting for subcellular localization","journal":"Journal of cellular physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP for interaction, epistasis rescue with inducible system, multiple cell lines, single lab","pmids":["30499104"],"is_preprint":false},{"year":2018,"finding":"MDT-28, the C. elegans orthologue of MED28, undergoes lysine acetylation (confirmed by anti-acetyl lysine immunoprecipitation of GFP::MDT-28). Valproic acid (an HDAC inhibitor) enhanced MDT-28 acetylation and decreased its nuclear localization as measured by FLIM, indicating that acetylation regulates the nuclear pool of MED28.","method":"Anti-acetyl lysine immunoprecipitation, GFP::MDT-28 expression in C. elegans, fluorescence lifetime imaging microscopy (FLIM)","journal":"Folia biologica","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, indirect pharmacological manipulation, C. elegans orthologue rather than mammalian MED28 directly","pmids":["29871732"],"is_preprint":false},{"year":2019,"finding":"E2F1, NRF1, ETS1, and C/EBPβ transcription factors increase MED28 promoter activity as shown by luciferase reporter assay. MED28 expression peaks at the G1-S transition and during mitosis. Overexpression of MED28 shortens both interphase and mitosis duration, increases micronucleus formation, nuclear budding, and aneuploidy in HeLa cells; knockdown has the opposite effect on cell cycle duration.","method":"Luciferase reporter assay, cell cycle synchronization (thymidine/nocodazole), live-cell imaging, flow cytometry, fluorescence microscopy, siRNA knockdown and overexpression","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (reporter assay, live imaging, FACS) with both KD and OE controls, single lab","pmids":["30970566"],"is_preprint":false},{"year":2020,"finding":"RCOR1 directly binds to MED28 and suppresses MED28-induced cancer stem cell-like properties (colony/sphere formation and CSC marker expression) in oral cavity squamous cell carcinoma cells. Overexpression of RCOR1 partly abrogated MED28-induced CSC marker upregulation.","method":"Co-immunoprecipitation (direct interaction), overexpression, colony/sphere formation assays, immunoblotting for CSC markers","journal":"Journal of oral pathology & medicine","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single Co-IP for interaction, functional rescue experiment, single lab","pmids":["32306431"],"is_preprint":false},{"year":2024,"finding":"MED28 knockdown in liver cancer cells (HepG2 and Huh7) induced cell cycle arrest and suppressed AKT/mTOR signaling, accompanied by reduced lipid accumulation and lower nuclear localization of SREBP1. Overexpression of MED28 upregulated AKT/mTOR signaling, placing MED28 as a positive regulator of this pathway in liver cancer.","method":"siRNA knockdown, overexpression, cell cycle analysis, immunoblotting for AKT/mTOR signaling components, nuclear fractionation for SREBP1","journal":"Journal of agricultural and food chemistry","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, pathway placement based on expression changes after KD/OE without direct mechanistic link established","pmids":["38619972"],"is_preprint":false}],"current_model":"MED28 is a dual-compartment protein that functions as a subunit of the mammalian Mediator transcriptional co-activator complex in the nucleus (where it acts as a scaffolding component of the head module, repressing smooth muscle cell differentiation and regulating pluripotency, cell cycle progression, and oncogenic transcriptional programs including Wnt/β-catenin and AKT/mTOR pathways) and as a cytoskeletal adaptor/scaffold in the cytoplasm (where it binds the NF2 tumor suppressor merlin and the adaptor Grb2, associates with the actin cytoskeleton, interacts with Src-family kinases including Fyn and Lck, and is phosphorylated at Y64 by Lck upon T-cell receptor stimulation, creating a Grb2-SH2 binding motif); through these activities MED28 promotes cellular proliferation, migration, and invasion in cancer cells via MEK1-MMP2, NFκB-Snail, and FOXM1-MMP2 axes."},"narrative":{"mechanistic_narrative":"MED28 is a dual-compartment protein that operates both as a subunit of the mammalian Mediator transcriptional co-activator complex in the nucleus and as a membrane-associated cytoskeletal adaptor in the cytoplasm [PMID:15467741, PMID:17848560]. As a Mediator head-module component, MED28 acts as a scaffolding protein that stabilizes a subcomplex with Med6, Med8, and Med18 and represses smooth muscle cell differentiation [PMID:17848560], and it is essential for pluripotency: loss of Med28 in mice causes peri-implantation lethality with collapse of the inner cell mass and reduced Oct4 and Nanog expression, while its overexpression enhances iPSC reprogramming [PMID:26445504]. MED28 expression peaks at the G1-S transition and during mitosis, and its level controls cell cycle duration and genomic stability, with overexpression driving micronucleus formation and aneuploidy [PMID:30970566]. In the cytoplasm MED28 binds the NF2 tumor suppressor merlin and the adaptor Grb2, forming a ternary complex beneath the plasma membrane in association with the actin cytoskeleton [PMID:15467741]; it interacts with Src-family kinases and is phosphorylated at Y64 by Lck upon T-cell receptor (CD3) stimulation, generating a Grb2-SH2 binding motif [PMID:16899217]. Across cancer contexts MED28 promotes proliferation, migration, and invasion through several transcriptional and signaling axes, including Wnt/β-catenin (repressing the negative regulator HBP1) [PMID:26660958], MEK1-MMP2 [PMID:22495818], and FOXM1-MMP2 [PMID:30499104], and it directly binds nuclear partners ZNF224 and RCOR1 to modulate cell survival and cancer stem cell-like properties [PMID:29435049, PMID:32306431].","teleology":[{"year":2004,"claim":"Established MED28 (magicin) as a cytoplasmic, membrane-proximal scaffold by identifying its direct physical partners, answering what this protein binds and where it resides.","evidence":"Co-IP, blot overlay, immunofluorescence, EM, and subcellular fractionation showing merlin and Grb2 binding and actin association","pmids":["15467741"],"confidence":"High","gaps":["Functional consequence of the merlin-MED28-Grb2 ternary complex not defined","No link yet to a signaling output or transcriptional role"]},{"year":2005,"claim":"Connected MED28 overexpression to proliferative and oncogenic signaling, showing it associates with c-Src and correlates with MAPK activation.","evidence":"Overexpression/knockdown, proliferation assays, xenograft model, and Co-IP for c-Src in cancer cells","pmids":["16024617"],"confidence":"Medium","gaps":["Whether MED28 directly activates Src or acts downstream not resolved","MAPK activation correlative rather than mechanistic"]},{"year":2006,"claim":"Defined MED28 as a substrate and partner of Src-family kinases and identified the exact tyrosine phosphorylation site coupling it to TCR signaling.","evidence":"Yeast two-hybrid, in vitro kinase assay, site-directed mutagenesis, and CD3 stimulation in Lck-deficient versus wild-type Jurkat cells","pmids":["16899217","16964398"],"confidence":"High","gaps":["Downstream signaling consequence of Y64 phosphorylation and Grb2 recruitment not traced","Conflicting reports on whether MED28 is a direct Src substrate"]},{"year":2007,"claim":"Placed MED28 in the nucleus as a Mediator head-module subunit and assigned it a scaffolding role repressing smooth muscle differentiation.","evidence":"Mediator subunit identification with siRNA knockdown/overexpression and transdifferentiation assays in NIH3T3 and mesenchymal precursors","pmids":["17848560"],"confidence":"Medium","gaps":["Direct target genes of the Med6/8/18/28 subcomplex not mapped","Relationship between nuclear and cytoplasmic pools unclear"]},{"year":2015,"claim":"Demonstrated an essential developmental requirement for MED28 in maintaining pluripotency, linking the Mediator subunit to Oct4/Nanog-driven inner cell mass identity.","evidence":"Full, conditional, and heterozygous Med28 knockout mice plus iPSC reprogramming assays","pmids":["26445504"],"confidence":"High","gaps":["Mechanism by which MED28 sustains Oct4/Nanog expression not defined","Whether the effect is via Mediator or a separable function untested"]},{"year":2015,"claim":"Identified MED28 as a repressor of the Wnt/β-catenin negative regulator HBP1, providing a transcriptional mechanism for its pro-tumorigenic activity in colorectal cancer.","evidence":"siRNA, overexpression, luciferase reporter of the HBP1 promoter, and immunoblotting for β-catenin targets","pmids":["26660958"],"confidence":"Medium","gaps":["Whether MED28 acts on the HBP1 promoter directly or through Mediator not established","Generalizability beyond colorectal cells untested"]},{"year":2012,"claim":"Established a MEK1-MMP2 axis as the mechanism for MED28-driven migration and invasion through ordered epistasis.","evidence":"Knockdown/overexpression, dominant-negative MEK1, MEK1 inhibitors, and MMP2 rescue in breast cancer migration/invasion assays","pmids":["22495818","21942447"],"confidence":"Medium","gaps":["How MED28 elevates MEK1 expression not defined","Direct versus indirect control of MMP2 unresolved"]},{"year":2018,"claim":"Showed MED28 partners with FOXM1 to drive MMP2-dependent invasion, and directly binds ZNF224 to stabilize it against degradation, expanding its nuclear interaction network.","evidence":"Co-IP, SPR, BiFC for ZNF224; Co-IP plus inducible constitutively active FOXM1 rescue in NSCLC and breast cancer cells","pmids":["30499104","29435049"],"confidence":"Medium","gaps":["Whether MED28-FOXM1 and MED28-ZNF224 functions involve Mediator recruitment unknown","Mechanism of ZNF224 stabilization not detailed"]},{"year":2019,"claim":"Defined cell-cycle-coupled regulation of MED28 itself and its dose-dependent control of mitotic timing and genomic stability.","evidence":"Luciferase reporters for E2F1/NRF1/ETS1/C/EBPβ, cell cycle synchronization, live-cell imaging, FACS with knockdown/overexpression in HeLa cells","pmids":["30970566"],"confidence":"Medium","gaps":["Molecular basis of MED28-driven aneuploidy not identified","Link to its Mediator or cytoplasmic functions not made"]},{"year":2020,"claim":"Identified RCOR1 as a direct binder that antagonizes MED28-induced cancer stem cell-like properties.","evidence":"Co-IP, overexpression, colony/sphere formation, and CSC marker immunoblotting in oral squamous carcinoma cells","pmids":["32306431"],"confidence":"Low","gaps":["Single Co-IP without reciprocal/orthogonal binding validation","Transcriptional targets of the MED28-RCOR1 interplay unknown"]},{"year":2024,"claim":"Linked MED28 to AKT/mTOR signaling and lipogenic SREBP1 regulation in liver cancer.","evidence":"siRNA/overexpression with cell cycle analysis, AKT/mTOR immunoblotting, and SREBP1 nuclear fractionation in HepG2/Huh7 cells","pmids":["38619972"],"confidence":"Low","gaps":["Pathway placement based on expression changes without direct mechanistic link","Whether effect is transcriptional or post-translational unresolved"]},{"year":null,"claim":"How MED28 is partitioned between its nuclear Mediator role and its cytoplasmic cytoskeletal/signaling role, and whether post-translational modifications such as Y64 phosphorylation or acetylation coordinate this switch, remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No mechanism reconciling nuclear and cytoplasmic pools in mammalian cells","Acetylation control of nuclear localization shown only for the C. elegans orthologue MDT-28 (PMID 29871732)","No structural model of MED28 within the Mediator head module"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[2,9]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,1]},{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[2]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[2,10,13]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[0]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[2,9]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[13]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[1,5]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[7]}],"complexes":["Mediator complex (head module: Med6/Med8/Med18/Med28)"],"partners":["NF2 (MERLIN)","GRB2","LCK","FYN","SRC","ZNF224","FOXM1","RCOR1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9H204","full_name":"Mediator of RNA polymerase II transcription subunit 28","aliases":["Endothelial-derived protein 1","Mediator complex subunit 28","Merlin and Grb2-interacting cytoskeletal protein","Magicin","Tumor angiogenesis marker EG-1"],"length_aa":178,"mass_kda":19.5,"function":"Component of the Mediator complex, a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. Mediator functions as a bridge to convey information from gene-specific regulatory proteins to the basal RNA polymerase II transcription machinery. Mediator is recruited to promoters by direct interactions with regulatory proteins and serves as a scaffold for the assembly of a functional preinitiation complex with RNA polymerase II and the general transcription factors. May be part of a complex containing NF2/merlin that participates in cellular signaling to the actin cytoskeleton downstream of tyrosine kinase signaling pathways","subcellular_location":"Nucleus; Cytoplasm; Membrane","url":"https://www.uniprot.org/uniprotkb/Q9H204/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/MED28","classification":"Common Essential","n_dependent_lines":1167,"n_total_lines":1208,"dependency_fraction":0.9660596026490066},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000118579","cell_line_id":"CID000243","localizations":[{"compartment":"nuclear_punctae","grade":3},{"compartment":"nucleoplasm","grade":3}],"interactors":[{"gene":"MED10","stoichiometry":10.0},{"gene":"MED11","stoichiometry":10.0},{"gene":"MED14","stoichiometry":10.0},{"gene":"MED17","stoichiometry":10.0},{"gene":"MED18","stoichiometry":10.0},{"gene":"MED19","stoichiometry":10.0},{"gene":"MED20","stoichiometry":10.0},{"gene":"MED21","stoichiometry":10.0},{"gene":"MED22","stoichiometry":10.0},{"gene":"MED27","stoichiometry":10.0}],"url":"https://opencell.sf.czbiohub.org/target/CID000243","total_profiled":1310},"omim":[{"mim_id":"620327","title":"NEURODEGENERATION WITH DEVELOPMENTAL DELAY, EARLY RESPIRATORY FAILURE, MYOCLONIC SEIZURES, AND BRAIN ABNORMALITIES; NDDRSB","url":"https://www.omim.org/entry/620327"},{"mim_id":"612383","title":"MEDIATOR COMPLEX SUBUNIT 11; MED11","url":"https://www.omim.org/entry/612383"},{"mim_id":"610311","title":"MEDIATOR COMPLEX SUBUNIT 28; MED28","url":"https://www.omim.org/entry/610311"},{"mim_id":"609423","title":"HUMAN IMMUNODEFICIENCY VIRUS TYPE 1, SUSCEPTIBILITY TO","url":"https://www.omim.org/entry/609423"},{"mim_id":"600069","title":"URIDINE DIPHOSPHATE GLYCOSYLTRANSFERASE 2 FAMILY, MEMBER B15; UGT2B15","url":"https://www.omim.org/entry/600069"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/MED28"},"hgnc":{"alias_symbol":["EG1","DKFZP434N185","magicin"],"prev_symbol":[]},"alphafold":{"accession":"Q9H204","domains":[{"cath_id":"1.20.58","chopping":"43-149","consensus_level":"medium","plddt":93.4937,"start":43,"end":149}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H204","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H204-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H204-F1-predicted_aligned_error_v6.png","plddt_mean":78.88},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MED28","jax_strain_url":"https://www.jax.org/strain/search?query=MED28"},"sequence":{"accession":"Q9H204","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9H204.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9H204/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H204"}},"corpus_meta":[{"pmid":"1714386","id":"PMC_1714386","title":"A new human p34 protein kinase, CDK2, identified by complementation of a cdc28 mutation in Saccharomyces cerevisiae, is a homolog of Xenopus Eg1.","date":"1991","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/1714386","citation_count":278,"is_preprint":false},{"pmid":"1373987","id":"PMC_1373987","title":"Application of monoclonal antibodies against major basic protein (BMK-13) and eosinophil cationic protein (EG1 and EG2) for quantifying eosinophils in bronchial biopsies from atopic asthma.","date":"1992","source":"Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology","url":"https://pubmed.ncbi.nlm.nih.gov/1373987","citation_count":91,"is_preprint":false},{"pmid":"15467741","id":"PMC_15467741","title":"Magicin, a novel cytoskeletal protein associates with the NF2 tumor suppressor merlin and Grb2.","date":"2004","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/15467741","citation_count":51,"is_preprint":false},{"pmid":"21942447","id":"PMC_21942447","title":"Resveratrol modulates MED28 (Magicin/EG-1) expression and inhibits epidermal growth factor (EGF)-induced migration in MDA-MB-231 human breast cancer cells.","date":"2011","source":"Journal of agricultural and food chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/21942447","citation_count":38,"is_preprint":false},{"pmid":"19830597","id":"PMC_19830597","title":"Determination of product inhibition of CBH1, CBH2, and EG1 using a novel cellulase activity assay.","date":"2009","source":"Applied biochemistry and biotechnology","url":"https://pubmed.ncbi.nlm.nih.gov/19830597","citation_count":24,"is_preprint":false},{"pmid":"22495818","id":"PMC_22495818","title":"MED28 regulates MEK1-dependent cellular migration in human breast cancer cells.","date":"2012","source":"Journal of cellular 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Shortens the Cell Cycle and Induces Genomic Instability.","date":"2019","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/30970566","citation_count":8,"is_preprint":false},{"pmid":"32306431","id":"PMC_32306431","title":"RCOR1 directly binds to MED28 and weakens its inducing effect on cancer stem cell-like activity of oral cavity squamous cell carcinoma cells.","date":"2020","source":"Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology","url":"https://pubmed.ncbi.nlm.nih.gov/32306431","citation_count":8,"is_preprint":false},{"pmid":"36072467","id":"PMC_36072467","title":"Bioactive Vitamin D Attenuates MED28-Mediated Cell Growth and Epithelial-Mesenchymal Transition in Human Colorectal Cancer Cells.","date":"2022","source":"BioMed research 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Pulp.","date":"2025","source":"Polymers","url":"https://pubmed.ncbi.nlm.nih.gov/40574241","citation_count":1,"is_preprint":false},{"pmid":"29871732","id":"PMC_29871732","title":"Valproic Acid Decreases the Nuclear Localization of MDT-28, the Nematode Orthologue of MED28.","date":"2018","source":"Folia biologica","url":"https://pubmed.ncbi.nlm.nih.gov/29871732","citation_count":0,"is_preprint":false},{"pmid":"34722257","id":"PMC_34722257","title":"Chemical Synthesis of the PAX Protein Inhibitor EG1 and Its Ability to Slow the Growth of Human Colorectal Carcinoma Cells.","date":"2021","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/34722257","citation_count":0,"is_preprint":false},{"pmid":"11477881","id":"PMC_11477881","title":"[The changes of EG1 and EG2 positive eosinophils and their clinical significance in asthmatics].","date":"1998","source":"Zhonghua jie he he hu xi za zhi = Zhonghua jiehe he huxi zazhi = Chinese journal of tuberculosis and respiratory 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MED28 also binds the adaptor protein Grb2 via Grb2-binding motifs in its sequence, and merlin can form a ternary complex with MED28 and Grb2.\",\n      \"method\": \"Co-immunoprecipitation, affinity binding, blot overlay, immunofluorescence microscopy, electron microscopy, subcellular fractionation\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (Co-IP, pulldown, blot overlay, EM, fractionation) in a single study establishing direct binding partners and localization\",\n      \"pmids\": [\"15467741\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"MED28 (magicin) is phosphorylated by Fyn tyrosine kinase in vitro. Lck and Src also interact with MED28. Upon CD3 stimulation in Jurkat T cells, MED28 is phosphorylated by Lck; phosphorylation is absent in Lck-deficient J.CaM1.6 cells. Site-directed mutagenesis identified Y64 as the phosphorylation site, creating an SH2-Grb2 binding motif.\",\n      \"method\": \"Yeast two-hybrid, in vitro kinase assay, site-directed mutagenesis, co-immunoprecipitation, stimulation with anti-CD3 antibody\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro kinase assay with mutagenesis identifying exact phosphorylation site, combined with cell-based epistasis using Lck-deficient line\",\n      \"pmids\": [\"16899217\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"MED28 (magicin) was independently identified as a subunit of the mammalian Mediator complex. Knockdown of Med28 in NIH3T3 cells induced smooth muscle cell (SMC) differentiation gene expression, while overexpression repressed it. Med28 functions as a repressor of SMC differentiation together with Mediator head module subunits Med6, Med8, and Med18, acting as a scaffolding protein that maintains stability of this head module subcomplex.\",\n      \"method\": \"siRNA knockdown, overexpression, gene expression analysis, multipotent mesenchymal precursor transdifferentiation assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean KD and OE with defined cellular phenotype and pathway placement within Mediator head module, single lab\",\n      \"pmids\": [\"17848560\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"EG-1 (MED28) overexpression stimulates cellular proliferation in vitro and in vivo (xenograft), and co-immunoprecipitation demonstrated an association between EG-1 and c-Src. Overexpression of EG-1 correlated with activation of ERK1/2, JNK, and p38 MAPK kinases.\",\n      \"method\": \"Transfection/overexpression, siRNA knockdown, proliferation assay, xenograft tumor model, co-immunoprecipitation, immunoblotting\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP demonstrating Src association, functional proliferation assay in vitro and in vivo, single lab\",\n      \"pmids\": [\"16024617\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"EG-1 (MED28) overexpression activates c-Src signaling and binds to other Src family members. EG-1 also shows interactions with multiple SH3- and WW-domain-containing signaling molecules, though EG-1 was found not to be a direct Src substrate.\",\n      \"method\": \"Overexpression, immunoprecipitation, immunoblotting for Src activation\",\n      \"journal\": \"International journal of oncology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single Co-IP/pulldown approach, single lab, negative result for direct phosphorylation noted\",\n      \"pmids\": [\"16964398\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"MED28 regulates cellular migration and invasion in human breast cancer cells in a MEK1-dependent manner. Suppression of MED28 reduced MMP2 and MEK1 expression and blocked migration/invasion; overexpression enhanced them. Dominant-negative MEK1, MEK1 siRNA, and MEK1 inhibitors all blocked MED28-induced MMP2 activation and migration. Ectopic MEK1 rescued MED28-knockdown invasion phenotype, and exogenous MMP2 rescued invasion upon MED28 or MEK1 knockdown.\",\n      \"method\": \"siRNA knockdown, overexpression, dominant-negative construct, MEK1 inhibitors, migration/invasion assays, epistasis rescue experiments\",\n      \"journal\": \"Journal of cellular physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — epistasis established by multiple genetic and pharmacological rescue experiments, single lab\",\n      \"pmids\": [\"22495818\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"MED28 overexpression increases EGF-induced cellular migration in MDA-MB-231 breast cancer cells, and its effect on migration occurs presumably through the EGFR/PI3K signaling pathway. Resveratrol suppressed EGF-mediated migration and reduced MED28 and MMP-9 expression.\",\n      \"method\": \"Overexpression, siRNA knockdown, migration assay, immunoblotting\",\n      \"journal\": \"Journal of agricultural and food chemistry\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, functional migration assay with overexpression/knockdown but PI3K pathway placement inferred rather than directly demonstrated\",\n      \"pmids\": [\"21942447\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Med28 knockout mice die at the peri-implantation stage due to loss of pluripotency of the inner cell mass, accompanied by reduced expression of pluripotency transcription factors Oct4 and Nanog. Overexpression of Med28 in mouse embryonic fibroblasts enhances reprogramming efficiency to iPSCs. Cre-mediated inactivation of Med28 in iPSCs causes cell death, and heterozygous loss leads to differentiation into trophectoderm and primitive endoderm lineages.\",\n      \"method\": \"Knockout mouse model, Cre-mediated conditional inactivation, iPSC reprogramming assay, gene expression analysis\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo knockout with defined developmental phenotype, multiple genetic models (full KO, conditional KO, heterozygous) with consistent results\",\n      \"pmids\": [\"26445504\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"MED28 modulates epithelial-mesenchymal transition (EMT) through NFκB in human breast cancer cells. Suppression of MED28 reduced p-NFκB/p65, Snail, and mesenchymal markers, and attenuated EMT induced by Adriamycin. Overexpression of MED28 enhanced EMT markers.\",\n      \"method\": \"siRNA knockdown, overexpression, Adriamycin-induced EMT model, immunoblotting for EMT markers and p-NFκB/p65\",\n      \"journal\": \"Journal of cellular physiology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single method set, NFκB pathway placement by correlation without direct mechanistic proof\",\n      \"pmids\": [\"27662245\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Suppression of MED28 in colorectal cancer cells reduced expression of cyclin D1, c-Myc, and nuclear β-catenin, and increased expression of E-cadherin and HBP1 (a negative regulator of Wnt/β-catenin signaling). MED28 knockdown increased HBP1 promoter reporter activity while overexpression decreased it, placing MED28 as a repressor of HBP1 in the Wnt/β-catenin pathway.\",\n      \"method\": \"siRNA knockdown, overexpression, luciferase reporter assay, immunoblotting\",\n      \"journal\": \"Journal of cellular physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — luciferase reporter assay combined with KD/OE and expression analysis establishing pathway placement, single lab\",\n      \"pmids\": [\"26660958\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"MED28 directly interacts with ZNF224 (a Krüppel-associated-box zinc finger protein) in the nucleus; the KRAB domain of ZNF224 interacts with the MED domain of MED28. Overexpression of MED28 inhibited camptothecin-induced degradation of ZNF224, stabilizing it and resulting in increased colony formation in MCF-7 cells.\",\n      \"method\": \"Co-immunoprecipitation, surface plasmon resonance, bimolecular fluorescence complementation, overexpression, colony formation assay\",\n      \"journal\": \"Oncology letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct binding confirmed by orthogonal methods (Co-IP + SPR + BiFC), functional consequence demonstrated, single lab\",\n      \"pmids\": [\"29435049\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"MED28 interacts with FOXM1 in NSCLC cells; both proteins mutually affect each other's expression levels and subcellular localization. Elevated MED28 and FOXM1 together increase MMP2 expression and enhance cell migration and invasion. MED28 siRNA-mediated MMP2 suppression was rescued by inducible constitutively active FOXM1, restoring migration and invasion.\",\n      \"method\": \"Co-immunoprecipitation, siRNA knockdown, doxycycline-inducible FOXM1 overexpression system, migration/invasion assays, immunoblotting for subcellular localization\",\n      \"journal\": \"Journal of cellular physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP for interaction, epistasis rescue with inducible system, multiple cell lines, single lab\",\n      \"pmids\": [\"30499104\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"MDT-28, the C. elegans orthologue of MED28, undergoes lysine acetylation (confirmed by anti-acetyl lysine immunoprecipitation of GFP::MDT-28). Valproic acid (an HDAC inhibitor) enhanced MDT-28 acetylation and decreased its nuclear localization as measured by FLIM, indicating that acetylation regulates the nuclear pool of MED28.\",\n      \"method\": \"Anti-acetyl lysine immunoprecipitation, GFP::MDT-28 expression in C. elegans, fluorescence lifetime imaging microscopy (FLIM)\",\n      \"journal\": \"Folia biologica\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, indirect pharmacological manipulation, C. elegans orthologue rather than mammalian MED28 directly\",\n      \"pmids\": [\"29871732\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"E2F1, NRF1, ETS1, and C/EBPβ transcription factors increase MED28 promoter activity as shown by luciferase reporter assay. MED28 expression peaks at the G1-S transition and during mitosis. Overexpression of MED28 shortens both interphase and mitosis duration, increases micronucleus formation, nuclear budding, and aneuploidy in HeLa cells; knockdown has the opposite effect on cell cycle duration.\",\n      \"method\": \"Luciferase reporter assay, cell cycle synchronization (thymidine/nocodazole), live-cell imaging, flow cytometry, fluorescence microscopy, siRNA knockdown and overexpression\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (reporter assay, live imaging, FACS) with both KD and OE controls, single lab\",\n      \"pmids\": [\"30970566\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"RCOR1 directly binds to MED28 and suppresses MED28-induced cancer stem cell-like properties (colony/sphere formation and CSC marker expression) in oral cavity squamous cell carcinoma cells. Overexpression of RCOR1 partly abrogated MED28-induced CSC marker upregulation.\",\n      \"method\": \"Co-immunoprecipitation (direct interaction), overexpression, colony/sphere formation assays, immunoblotting for CSC markers\",\n      \"journal\": \"Journal of oral pathology & medicine\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single Co-IP for interaction, functional rescue experiment, single lab\",\n      \"pmids\": [\"32306431\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"MED28 knockdown in liver cancer cells (HepG2 and Huh7) induced cell cycle arrest and suppressed AKT/mTOR signaling, accompanied by reduced lipid accumulation and lower nuclear localization of SREBP1. Overexpression of MED28 upregulated AKT/mTOR signaling, placing MED28 as a positive regulator of this pathway in liver cancer.\",\n      \"method\": \"siRNA knockdown, overexpression, cell cycle analysis, immunoblotting for AKT/mTOR signaling components, nuclear fractionation for SREBP1\",\n      \"journal\": \"Journal of agricultural and food chemistry\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, pathway placement based on expression changes after KD/OE without direct mechanistic link established\",\n      \"pmids\": [\"38619972\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"MED28 is a dual-compartment protein that functions as a subunit of the mammalian Mediator transcriptional co-activator complex in the nucleus (where it acts as a scaffolding component of the head module, repressing smooth muscle cell differentiation and regulating pluripotency, cell cycle progression, and oncogenic transcriptional programs including Wnt/β-catenin and AKT/mTOR pathways) and as a cytoskeletal adaptor/scaffold in the cytoplasm (where it binds the NF2 tumor suppressor merlin and the adaptor Grb2, associates with the actin cytoskeleton, interacts with Src-family kinases including Fyn and Lck, and is phosphorylated at Y64 by Lck upon T-cell receptor stimulation, creating a Grb2-SH2 binding motif); through these activities MED28 promotes cellular proliferation, migration, and invasion in cancer cells via MEK1-MMP2, NFκB-Snail, and FOXM1-MMP2 axes.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MED28 is a dual-compartment protein that operates both as a subunit of the mammalian Mediator transcriptional co-activator complex in the nucleus and as a membrane-associated cytoskeletal adaptor in the cytoplasm [#0, #2]. As a Mediator head-module component, MED28 acts as a scaffolding protein that stabilizes a subcomplex with Med6, Med8, and Med18 and represses smooth muscle cell differentiation [#2], and it is essential for pluripotency: loss of Med28 in mice causes peri-implantation lethality with collapse of the inner cell mass and reduced Oct4 and Nanog expression, while its overexpression enhances iPSC reprogramming [#7]. MED28 expression peaks at the G1-S transition and during mitosis, and its level controls cell cycle duration and genomic stability, with overexpression driving micronucleus formation and aneuploidy [#13]. In the cytoplasm MED28 binds the NF2 tumor suppressor merlin and the adaptor Grb2, forming a ternary complex beneath the plasma membrane in association with the actin cytoskeleton [#0]; it interacts with Src-family kinases and is phosphorylated at Y64 by Lck upon T-cell receptor (CD3) stimulation, generating a Grb2-SH2 binding motif [#1]. Across cancer contexts MED28 promotes proliferation, migration, and invasion through several transcriptional and signaling axes, including Wnt/\\u03b2-catenin (repressing the negative regulator HBP1) [#9], MEK1-MMP2 [#5], and FOXM1-MMP2 [#11], and it directly binds nuclear partners ZNF224 and RCOR1 to modulate cell survival and cancer stem cell-like properties [#10, #14].\",\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Established MED28 (magicin) as a cytoplasmic, membrane-proximal scaffold by identifying its direct physical partners, answering what this protein binds and where it resides.\",\n      \"evidence\": \"Co-IP, blot overlay, immunofluorescence, EM, and subcellular fractionation showing merlin and Grb2 binding and actin association\",\n      \"pmids\": [\"15467741\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional consequence of the merlin-MED28-Grb2 ternary complex not defined\", \"No link yet to a signaling output or transcriptional role\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Connected MED28 overexpression to proliferative and oncogenic signaling, showing it associates with c-Src and correlates with MAPK activation.\",\n      \"evidence\": \"Overexpression/knockdown, proliferation assays, xenograft model, and Co-IP for c-Src in cancer cells\",\n      \"pmids\": [\"16024617\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether MED28 directly activates Src or acts downstream not resolved\", \"MAPK activation correlative rather than mechanistic\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Defined MED28 as a substrate and partner of Src-family kinases and identified the exact tyrosine phosphorylation site coupling it to TCR signaling.\",\n      \"evidence\": \"Yeast two-hybrid, in vitro kinase assay, site-directed mutagenesis, and CD3 stimulation in Lck-deficient versus wild-type Jurkat cells\",\n      \"pmids\": [\"16899217\", \"16964398\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Downstream signaling consequence of Y64 phosphorylation and Grb2 recruitment not traced\", \"Conflicting reports on whether MED28 is a direct Src substrate\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Placed MED28 in the nucleus as a Mediator head-module subunit and assigned it a scaffolding role repressing smooth muscle differentiation.\",\n      \"evidence\": \"Mediator subunit identification with siRNA knockdown/overexpression and transdifferentiation assays in NIH3T3 and mesenchymal precursors\",\n      \"pmids\": [\"17848560\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct target genes of the Med6/8/18/28 subcomplex not mapped\", \"Relationship between nuclear and cytoplasmic pools unclear\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Demonstrated an essential developmental requirement for MED28 in maintaining pluripotency, linking the Mediator subunit to Oct4/Nanog-driven inner cell mass identity.\",\n      \"evidence\": \"Full, conditional, and heterozygous Med28 knockout mice plus iPSC reprogramming assays\",\n      \"pmids\": [\"26445504\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism by which MED28 sustains Oct4/Nanog expression not defined\", \"Whether the effect is via Mediator or a separable function untested\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Identified MED28 as a repressor of the Wnt/\\u03b2-catenin negative regulator HBP1, providing a transcriptional mechanism for its pro-tumorigenic activity in colorectal cancer.\",\n      \"evidence\": \"siRNA, overexpression, luciferase reporter of the HBP1 promoter, and immunoblotting for \\u03b2-catenin targets\",\n      \"pmids\": [\"26660958\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether MED28 acts on the HBP1 promoter directly or through Mediator not established\", \"Generalizability beyond colorectal cells untested\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Established a MEK1-MMP2 axis as the mechanism for MED28-driven migration and invasion through ordered epistasis.\",\n      \"evidence\": \"Knockdown/overexpression, dominant-negative MEK1, MEK1 inhibitors, and MMP2 rescue in breast cancer migration/invasion assays\",\n      \"pmids\": [\"22495818\", \"21942447\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How MED28 elevates MEK1 expression not defined\", \"Direct versus indirect control of MMP2 unresolved\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Showed MED28 partners with FOXM1 to drive MMP2-dependent invasion, and directly binds ZNF224 to stabilize it against degradation, expanding its nuclear interaction network.\",\n      \"evidence\": \"Co-IP, SPR, BiFC for ZNF224; Co-IP plus inducible constitutively active FOXM1 rescue in NSCLC and breast cancer cells\",\n      \"pmids\": [\"30499104\", \"29435049\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether MED28-FOXM1 and MED28-ZNF224 functions involve Mediator recruitment unknown\", \"Mechanism of ZNF224 stabilization not detailed\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Defined cell-cycle-coupled regulation of MED28 itself and its dose-dependent control of mitotic timing and genomic stability.\",\n      \"evidence\": \"Luciferase reporters for E2F1/NRF1/ETS1/C/EBP\\u03b2, cell cycle synchronization, live-cell imaging, FACS with knockdown/overexpression in HeLa cells\",\n      \"pmids\": [\"30970566\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular basis of MED28-driven aneuploidy not identified\", \"Link to its Mediator or cytoplasmic functions not made\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identified RCOR1 as a direct binder that antagonizes MED28-induced cancer stem cell-like properties.\",\n      \"evidence\": \"Co-IP, overexpression, colony/sphere formation, and CSC marker immunoblotting in oral squamous carcinoma cells\",\n      \"pmids\": [\"32306431\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Single Co-IP without reciprocal/orthogonal binding validation\", \"Transcriptional targets of the MED28-RCOR1 interplay unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Linked MED28 to AKT/mTOR signaling and lipogenic SREBP1 regulation in liver cancer.\",\n      \"evidence\": \"siRNA/overexpression with cell cycle analysis, AKT/mTOR immunoblotting, and SREBP1 nuclear fractionation in HepG2/Huh7 cells\",\n      \"pmids\": [\"38619972\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Pathway placement based on expression changes without direct mechanistic link\", \"Whether effect is transcriptional or post-translational unresolved\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How MED28 is partitioned between its nuclear Mediator role and its cytoplasmic cytoskeletal/signaling role, and whether post-translational modifications such as Y64 phosphorylation or acetylation coordinate this switch, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No mechanism reconciling nuclear and cytoplasmic pools in mammalian cells\", \"Acetylation control of nuclear localization shown only for the C. elegans orthologue MDT-28 (PMID 29871732)\", \"No structural model of MED28 within the Mediator head module\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [2, 9]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [2, 10, 13]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [2, 9]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [13]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 5]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [7]}\n    ],\n    \"complexes\": [\"Mediator complex (head module: Med6/Med8/Med18/Med28)\"],\n    \"partners\": [\"NF2 (merlin)\", \"GRB2\", \"LCK\", \"FYN\", \"SRC\", \"ZNF224\", \"FOXM1\", \"RCOR1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}