{"gene":"GTF2H4","run_date":"2026-06-10T01:55:21","timeline":{"discoveries":[{"year":1997,"finding":"Yeast Tfb2 (ortholog of human GTF2H4/p52) is an essential TFIIH subunit; a C-terminal deletion of Tfb2 causes defective nucleotide excision repair (NER), demonstrated by UV sensitivity and loss of NER activity in cell extracts that was restored by purified TFIIH.","method":"Yeast genetics (deletion/truncation mutants), UV sensitivity assay, cell-extract NER complementation assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic loss-of-function with defined cellular phenotype (UV sensitivity, NER defect) complemented by purified TFIIH; replicated across multiple assays in one study","pmids":["9235928"],"is_preprint":false},{"year":1997,"finding":"The deduced amino acid sequence of yeast Tfb2 is similar to the 52-kDa subunit of human TFIIH (GTF2H4), establishing a one-to-one correspondence between yeast and human TFIIH polypeptides.","method":"Sequence alignment and gene cloning","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 3 / Strong — sequence homology with functional validation of the yeast ortholog; single study but foundational identification","pmids":["9235928"],"is_preprint":false},{"year":2007,"finding":"Yeast Tfb5 interacts directly with the TFIIH core subunit Tfb2 (GTF2H4 ortholog) but not with other NER proteins; this Tfb5-Tfb2 interaction is required for efficient NER, as deletion of the Tfb5-interacting domain of Tfb2 impairs NER function.","method":"Co-immunoprecipitation, domain deletion mapping, UV sensitivity and NER complementation assays in yeast cell extracts","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal interaction mapping plus functional NER complementation, multiple orthogonal methods in a single study","pmids":["17215295"],"is_preprint":false},{"year":2009,"finding":"Yeast Tfb2 (GTF2H4 ortholog) bridges the Ssl2 (XPB) helicase and the NER-specific Tfb5 subunit within TFIIH; the Tfb5-interacting domain of Tfb2 also binds nucleic acids, and addition of Tfb5 triggers dissociation of nucleic acids from Tfb2.","method":"Protein interaction assays (pulldown/co-immunoprecipitation), nucleic-acid binding assays, genetic epistasis (combining tfb5Δ with Tfb2 domain deletions in yeast)","journal":"DNA repair","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct binding assays plus genetic epistasis, single lab with multiple orthogonal methods","pmids":["19897425"],"is_preprint":false},{"year":2010,"finding":"The crystal structure of the complex between Tfb5 and the C-terminal region of Tfb2 (GTF2H4 ortholog) from S. cerevisiae was determined at 1.7 Å resolution, revealing the molecular basis of the Tfb5-Tfb2 interaction essential for NER.","method":"X-ray crystallography (crystal structure at 1.7 Å resolution)","journal":"Acta crystallographica. Section D, Biological crystallography","confidence":"High","confidence_rationale":"Tier 1 / Moderate — high-resolution crystal structure with functional context from prior NER studies; single lab but atomic-resolution structural determination","pmids":["20606254"],"is_preprint":false},{"year":2022,"finding":"Systematic mutagenesis of the HubA region of yeast Tfb2 (GTF2H4 ortholog) identified specific residues required for stable incorporation of XPB/Ssl2 into TFIIH; mutations in HubA caused defects in Ssl2 association (confirmed in human cells), impaired GAL gene induction, and reduced TFIIH and RNA pol II occupancy at gene promoters. Tfb6 genetically suppresses HubA mutant growth defects by modulating Ssl2 dissociation from TFIIH.","method":"Systematic site-directed mutagenesis, yeast growth assays, crosslinking-mass spectrometry, cryo-EM structural data, co-immunoprecipitation in yeast and human cells, ChIP (TFIIH/pol II occupancy), gene expression assays","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — mutagenesis combined with structural data (cryo-EM/XL-MS), biochemical co-IP in two organisms, and chromatin occupancy assays; multiple orthogonal methods in one rigorous study","pmids":["36041630"],"is_preprint":false},{"year":2024,"finding":"Human GTF2H4 acts as a positive regulator of partial endothelial-to-mesenchymal transition (EndMT) under hypoxic/ischemic conditions; it collaborates with ERCC3 to co-regulate partial EndMT, and promotes phosphorylation of NCOA3 at serine 1330 (identified by phosphorylation proteomics and confirmed by site-directed mutagenesis), which enhances NCOA3-p65 interaction and transcriptional activation of NF-κB/Snail signaling.","method":"Phosphorylation proteomics, site-directed mutagenesis, co-immunoprecipitation (NCOA3-p65 interaction), in vitro and in vivo (ischemic injury) loss/gain-of-function experiments","journal":"Innovation (Cambridge (Mass.))","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — phosphoproteomics plus mutagenesis plus co-IP plus in vivo validation, single lab but multiple orthogonal methods","pmids":["38379791"],"is_preprint":false}],"current_model":"GTF2H4 (p52) is an essential subunit of the TFIIH core complex that, through its C-terminal HubA domain, stably incorporates the XPB/Ssl2 DNA translocase into TFIIH to enable promoter opening for RNA pol II transcription and nucleotide excision repair; its C-terminal region also directly contacts and recruits the accessory NER factor p8/Tfb5, while in endothelial cells GTF2H4 additionally promotes NF-κB/Snail-driven partial endothelial-to-mesenchymal transition by facilitating NCOA3 phosphorylation at S1330 and its interaction with p65."},"narrative":{"mechanistic_narrative":"GTF2H4 (p52) is an essential subunit of the TFIIH core complex required for nucleotide excision repair and RNA polymerase II transcription, established through its yeast ortholog Tfb2 whose C-terminal truncation abolishes NER and confers UV sensitivity [PMID:9235928]. Its central architectural role is to anchor the XPB/Ssl2 DNA translocase within TFIIH: residues of the C-terminal HubA region are required for stable Ssl2/XPB incorporation, and HubA mutations reduce TFIIH and pol II promoter occupancy and impair gene induction, with the Tfb6 factor genetically modulating Ssl2 dissociation [PMID:36041630]. The same C-terminal region directly and selectively contacts the accessory NER subunit Tfb5/p8 — an interaction resolved at atomic resolution and functionally required for efficient repair — thereby bridging the XPB helicase to Tfb5; this domain also binds nucleic acids, and Tfb5 binding displaces the bound nucleic acid [PMID:17215295, PMID:19897425, PMID:20606254]. Beyond its core transcription/repair role, GTF2H4 acts in endothelial cells as a positive regulator of partial endothelial-to-mesenchymal transition under ischemic conditions, where, together with ERCC3, it promotes NCOA3 phosphorylation at serine 1330 to enhance NCOA3–p65 interaction and NF-κB/Snail signaling [PMID:38379791].","teleology":[{"year":1997,"claim":"Established that the p52 subunit is an essential TFIIH component whose C-terminus is specifically required for NER, defining its functional importance and the human-yeast orthology.","evidence":"Yeast deletion/truncation genetics with UV sensitivity and cell-extract NER complementation by purified TFIIH, plus sequence alignment to human p52","pmids":["9235928"],"confidence":"High","gaps":["Did not resolve which TFIIH interactions the C-terminus mediates","No structural or biochemical mechanism for the repair defect"]},{"year":2007,"claim":"Identified a direct, selective Tfb2/p52 contact with the accessory subunit Tfb5/p8, localizing the repair-critical function to a specific interaction interface.","evidence":"Co-IP, domain deletion mapping, and UV/NER complementation in yeast extracts","pmids":["17215295"],"confidence":"High","gaps":["Structural basis of the interface unknown","Effect on XPB/Ssl2 not addressed"]},{"year":2009,"claim":"Showed Tfb2/p52 functions as a bridge linking the Ssl2/XPB helicase to Tfb5, and that the Tfb5-interacting domain binds nucleic acids in a manner reversed by Tfb5, hinting at a regulatory switch.","evidence":"Pulldown/co-IP, nucleic-acid binding assays, and genetic epistasis in yeast","pmids":["19897425"],"confidence":"Medium","gaps":["Functional consequence of nucleic-acid displacement during NER not defined","Single-lab biochemistry"]},{"year":2010,"claim":"Provided the atomic-resolution basis for the p52-p8 interaction, converting the genetic/biochemical interface into a defined structure.","evidence":"X-ray crystallography of Tfb5 with the Tfb2 C-terminal region at 1.7 Å","pmids":["20606254"],"confidence":"High","gaps":["Structure of full-length p52 within intact TFIIH not resolved","Does not capture XPB-bound state"]},{"year":2022,"claim":"Defined the HubA region as the determinant for stable XPB/Ssl2 incorporation into TFIIH and linked this to promoter occupancy and transcriptional activation, mechanistically connecting p52 architecture to function in both yeast and human cells.","evidence":"Systematic mutagenesis, XL-MS, cryo-EM, co-IP in yeast and human cells, ChIP, and gene expression assays","pmids":["36041630"],"confidence":"High","gaps":["Role of Tfb6-equivalent regulation in human cells not established","Dynamics of Ssl2 association/dissociation during the catalytic cycle incomplete"]},{"year":2024,"claim":"Extended GTF2H4 function beyond core transcription/repair to a signaling role in endothelial cells, identifying an NCOA3 phosphorylation event that drives NF-κB/Snail-mediated partial EndMT.","evidence":"Phosphoproteomics, site-directed mutagenesis, co-IP, and in vitro/in vivo ischemic injury loss/gain-of-function","pmids":["38379791"],"confidence":"Medium","gaps":["Whether GTF2H4 directly phosphorylates NCOA3 or acts via an associated kinase is unresolved","Relationship between TFIIH core function and the EndMT role not mechanistically connected","Single-lab finding"]},{"year":null,"claim":"How GTF2H4's canonical TFIIH-scaffolding role mechanistically intersects with its context-specific EndMT signaling function remains unknown.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structure of human GTF2H4 in the EndMT signaling context","Kinase responsible for NCOA3 S1330 phosphorylation unidentified"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003723","term_label":"RNA binding","supporting_discovery_ids":[3]},{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[0,5]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[3,5]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[5]}],"pathway":[{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[0,2]},{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[5]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[6]}],"complexes":["TFIIH"],"partners":["ERCC3","GTF2H5","NCOA3"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q92759","full_name":"General transcription factor IIH subunit 4","aliases":["Basic transcription factor 2 52 kDa subunit","BTF2 p52","General transcription factor IIH polypeptide 4","TFIIH basal transcription factor complex p52 subunit"],"length_aa":462,"mass_kda":52.2,"function":"Component of the general transcription and DNA repair factor IIH (TFIIH) core complex, which is involved in general and transcription-coupled nucleotide excision repair (NER) of damaged DNA and, when complexed to CAK, in RNA transcription by RNA polymerase II. In NER, TFIIH acts by opening DNA around the lesion to allow the excision of the damaged oligonucleotide and its replacement by a new DNA fragment. In transcription, TFIIH has an essential role in transcription initiation. When the pre-initiation complex (PIC) has been established, TFIIH is required for promoter opening and promoter escape. Phosphorylation of the C-terminal tail (CTD) of the largest subunit of RNA polymerase II by the kinase module CAK controls the initiation of transcription Stimulates the ATPase activity of TFIIH subunit XPB/ERCC3 (PubMed:17466626)","subcellular_location":"Nucleus","url":"https://www.uniprot.org/uniprotkb/Q92759/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/GTF2H4","classification":"Common Essential","n_dependent_lines":1154,"n_total_lines":1208,"dependency_fraction":0.9552980132450332},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CDC7","stoichiometry":10.0},{"gene":"CDK7","stoichiometry":0.2},{"gene":"CETN2","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/GTF2H4","total_profiled":1310},"omim":[{"mim_id":"621435","title":"XERODERMA PIGMENTOSUM, COMPLEMENTATION GROUP J; XPJ","url":"https://www.omim.org/entry/621435"},{"mim_id":"604809","title":"PANBRONCHIOLITIS, DIFFUSE","url":"https://www.omim.org/entry/604809"},{"mim_id":"601760","title":"GENERAL TRANSCRIPTION FACTOR IIH, POLYPEPTIDE 4; GTF2H4","url":"https://www.omim.org/entry/601760"},{"mim_id":"133510","title":"ERCC EXCISION REPAIR 3, TFIIH CORE COMPLEX HELICASE SUBUNIT; ERCC3","url":"https://www.omim.org/entry/133510"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nuclear speckles","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/GTF2H4"},"hgnc":{"alias_symbol":["TFB2","TFIIH","P52"],"prev_symbol":[]},"alphafold":{"accession":"Q92759","domains":[{"cath_id":"1.10.10","chopping":"18-122","consensus_level":"high","plddt":91.607,"start":18,"end":122},{"cath_id":"-","chopping":"133-288","consensus_level":"high","plddt":88.0474,"start":133,"end":288},{"cath_id":"-","chopping":"306-398","consensus_level":"high","plddt":91.7963,"start":306,"end":398},{"cath_id":"3.30.70.2610","chopping":"406-460","consensus_level":"high","plddt":91.9531,"start":406,"end":460}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q92759","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q92759-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q92759-F1-predicted_aligned_error_v6.png","plddt_mean":85.25},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=GTF2H4","jax_strain_url":"https://www.jax.org/strain/search?query=GTF2H4"},"sequence":{"accession":"Q92759","fasta_url":"https://rest.uniprot.org/uniprotkb/Q92759.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q92759/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q92759"}},"corpus_meta":[{"pmid":"19945377","id":"PMC_19945377","title":"TFB2 is a transient component of the catalytic site of the human mitochondrial RNA polymerase.","date":"2009","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/19945377","citation_count":110,"is_preprint":false},{"pmid":"17275836","id":"PMC_17275836","title":"TFB1 or TFB2 is sufficient for Thermococcus kodakaraensis viability and for basal transcription in vitro.","date":"2006","source":"Journal of molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/17275836","citation_count":66,"is_preprint":false},{"pmid":"9235928","id":"PMC_9235928","title":"Genes for Tfb2, Tfb3, and Tfb4 subunits of yeast transcription/repair factor IIH. Homology to human cyclin-dependent kinase activating kinase and IIH subunits.","date":"1997","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9235928","citation_count":65,"is_preprint":false},{"pmid":"30642396","id":"PMC_30642396","title":"Whole-genome methylation profiling of the retinal pigment epithelium of individuals with age-related macular degeneration reveals differential methylation of the SKI, GTF2H4, and TNXB genes.","date":"2019","source":"Clinical epigenetics","url":"https://pubmed.ncbi.nlm.nih.gov/30642396","citation_count":48,"is_preprint":false},{"pmid":"38379791","id":"PMC_38379791","title":"GTF2H4 regulates partial EndMT via NF-κB activation through NCOA3 phosphorylation in ischemic diseases.","date":"2024","source":"Innovation (Cambridge (Mass.))","url":"https://pubmed.ncbi.nlm.nih.gov/38379791","citation_count":16,"is_preprint":false},{"pmid":"17215295","id":"PMC_17215295","title":"Tfb5 interacts with Tfb2 and facilitates nucleotide excision repair in yeast.","date":"2007","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/17215295","citation_count":16,"is_preprint":false},{"pmid":"27288692","id":"PMC_27288692","title":"Genetic variant in DNA repair gene GTF2H4 is associated with lung cancer risk: a large-scale analysis of six published GWAS datasets in the TRICL consortium.","date":"2016","source":"Carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/27288692","citation_count":15,"is_preprint":false},{"pmid":"19897425","id":"PMC_19897425","title":"Interacting partners of the Tfb2 subunit from yeast TFIIH.","date":"2009","source":"DNA repair","url":"https://pubmed.ncbi.nlm.nih.gov/19897425","citation_count":10,"is_preprint":false},{"pmid":"19096125","id":"PMC_19096125","title":"Mitochondrial transcription factors TFA, TFB1 and TFB2: a search for DNA variants/haplotypes and the risk of cardiac hypertrophy.","date":"2008","source":"Disease markers","url":"https://pubmed.ncbi.nlm.nih.gov/19096125","citation_count":9,"is_preprint":false},{"pmid":"36041630","id":"PMC_36041630","title":"Systematic mutagenesis of TFIIH subunit p52/Tfb2 identifies residues required for XPB/Ssl2 subunit function and genetic interactions with TFB6.","date":"2022","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/36041630","citation_count":6,"is_preprint":false},{"pmid":"20606254","id":"PMC_20606254","title":"Structure determination of the minimal complex between Tfb5 and Tfb2, two subunits of the yeast transcription/DNA-repair factor TFIIH: a retrospective study.","date":"2010","source":"Acta crystallographica. Section D, Biological crystallography","url":"https://pubmed.ncbi.nlm.nih.gov/20606254","citation_count":3,"is_preprint":false},{"pmid":"22524621","id":"PMC_22524621","title":"Lack of association between GTF2H4 genetic variants and AERD development and FEV1 decline by aspirin provocation.","date":"2012","source":"International journal of immunogenetics","url":"https://pubmed.ncbi.nlm.nih.gov/22524621","citation_count":1,"is_preprint":false},{"pmid":"41629034","id":"PMC_41629034","title":"Comparative roles of four TFIIH subunits (Tfb1, Tfb2, Tfb4 and Tfb5) in anti-UV and insecticidal processes of Beauveria bassiana.","date":"2026","source":"Pesticide biochemistry and physiology","url":"https://pubmed.ncbi.nlm.nih.gov/41629034","citation_count":0,"is_preprint":false},{"pmid":"40162875","id":"PMC_40162875","title":"LTD1 plays a key role in rice tillering regulation through cooperation with CycH1;1 and TFB2 subunits of the TFIIH complex.","date":"2025","source":"The Plant journal : for cell and molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/40162875","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":9470,"output_tokens":2515,"usd":0.033067,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8797,"output_tokens":2391,"usd":0.05188,"stage2_stop_reason":"end_turn"},"total_usd":0.084947,"stage1_batch_id":"msgbatch_01DUPACZi7AAWwuZiUjseQF4","stage2_batch_id":"msgbatch_018yt7chE3f48PEFtDwtj6AE","note":"batch pricing = 50% of standard"},"stage1_raw":"I need to carefully classify each paper before extracting discoveries.\n\n**Classification:**\n\n1. PMID:19945377 - TFB2 as mitochondrial transcription factor (TFB2M). This is the mitochondrial TFB2 (TFAM family), NOT GTF2H4 (TFIIH subunit p52). Different gene — EXCLUDE.\n\n2. PMID:17275836 - TFB2 in Thermococcus kodakaraensis (archaeal). Different organism/gene family — EXCLUDE.\n\n3. PMID:9235928 - Yeast Tfb2 as subunit of TFIIH, homolog of human 52-kDa subunit (GTF2H4). This is the ortholog — INCLUDE.\n\n4. PMID:30642396 - Epigenome/methylation study of GTF2H4 in AMD. No mechanistic experiment — EXCLUDE.\n\n5. PMID:38379791 - GTF2H4 in EndMT, NF-κB, NCOA3 phosphorylation. Direct experiments — INCLUDE.\n\n6. PMID:17215295 - Yeast Tfb5 interacts with Tfb2 (GTF2H4 ortholog). Mechanistic — INCLUDE.\n\n7. PMID:27288692 - GWAS/expression association study — EXCLUDE.\n\n8. PMID:19897425 - Yeast Tfb2 interactions with Ssl2 and Tfb5. Mechanistic — INCLUDE.\n\n9. PMID:19096125 - Mitochondrial TFB2M cardiac hypertrophy. Different gene (TFB2M not GTF2H4) — EXCLUDE.\n\n10. PMID:36041630 - Systematic mutagenesis of p52/Tfb2 (GTF2H4 ortholog). Mechanistic — INCLUDE.\n\n11. PMID:20606254 - Crystal structure of Tfb5-Tfb2C complex (GTF2H4 ortholog). Mechanistic — INCLUDE.\n\n12. PMID:22524621 - GWAS/association study with negative results — EXCLUDE.\n\n13. PMID:41629034 - Beauveria bassiana (filamentous fungus). Symbol collision (fungal Tfb2), not mammalian ortholog — EXCLUDE.\n\n14. PMID:40162875 - Rice TFB2 in TFIIH complex (plant). Symbol collision — EXCLUDE.\n\n```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1997,\n      \"finding\": \"Yeast Tfb2 (ortholog of human GTF2H4/p52) is an essential TFIIH subunit; a C-terminal deletion of Tfb2 causes defective nucleotide excision repair (NER), demonstrated by UV sensitivity and loss of NER activity in cell extracts that was restored by purified TFIIH.\",\n      \"method\": \"Yeast genetics (deletion/truncation mutants), UV sensitivity assay, cell-extract NER complementation assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic loss-of-function with defined cellular phenotype (UV sensitivity, NER defect) complemented by purified TFIIH; replicated across multiple assays in one study\",\n      \"pmids\": [\"9235928\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"The deduced amino acid sequence of yeast Tfb2 is similar to the 52-kDa subunit of human TFIIH (GTF2H4), establishing a one-to-one correspondence between yeast and human TFIIH polypeptides.\",\n      \"method\": \"Sequence alignment and gene cloning\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Strong — sequence homology with functional validation of the yeast ortholog; single study but foundational identification\",\n      \"pmids\": [\"9235928\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Yeast Tfb5 interacts directly with the TFIIH core subunit Tfb2 (GTF2H4 ortholog) but not with other NER proteins; this Tfb5-Tfb2 interaction is required for efficient NER, as deletion of the Tfb5-interacting domain of Tfb2 impairs NER function.\",\n      \"method\": \"Co-immunoprecipitation, domain deletion mapping, UV sensitivity and NER complementation assays in yeast cell extracts\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal interaction mapping plus functional NER complementation, multiple orthogonal methods in a single study\",\n      \"pmids\": [\"17215295\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Yeast Tfb2 (GTF2H4 ortholog) bridges the Ssl2 (XPB) helicase and the NER-specific Tfb5 subunit within TFIIH; the Tfb5-interacting domain of Tfb2 also binds nucleic acids, and addition of Tfb5 triggers dissociation of nucleic acids from Tfb2.\",\n      \"method\": \"Protein interaction assays (pulldown/co-immunoprecipitation), nucleic-acid binding assays, genetic epistasis (combining tfb5Δ with Tfb2 domain deletions in yeast)\",\n      \"journal\": \"DNA repair\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct binding assays plus genetic epistasis, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"19897425\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"The crystal structure of the complex between Tfb5 and the C-terminal region of Tfb2 (GTF2H4 ortholog) from S. cerevisiae was determined at 1.7 Å resolution, revealing the molecular basis of the Tfb5-Tfb2 interaction essential for NER.\",\n      \"method\": \"X-ray crystallography (crystal structure at 1.7 Å resolution)\",\n      \"journal\": \"Acta crystallographica. Section D, Biological crystallography\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — high-resolution crystal structure with functional context from prior NER studies; single lab but atomic-resolution structural determination\",\n      \"pmids\": [\"20606254\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Systematic mutagenesis of the HubA region of yeast Tfb2 (GTF2H4 ortholog) identified specific residues required for stable incorporation of XPB/Ssl2 into TFIIH; mutations in HubA caused defects in Ssl2 association (confirmed in human cells), impaired GAL gene induction, and reduced TFIIH and RNA pol II occupancy at gene promoters. Tfb6 genetically suppresses HubA mutant growth defects by modulating Ssl2 dissociation from TFIIH.\",\n      \"method\": \"Systematic site-directed mutagenesis, yeast growth assays, crosslinking-mass spectrometry, cryo-EM structural data, co-immunoprecipitation in yeast and human cells, ChIP (TFIIH/pol II occupancy), gene expression assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — mutagenesis combined with structural data (cryo-EM/XL-MS), biochemical co-IP in two organisms, and chromatin occupancy assays; multiple orthogonal methods in one rigorous study\",\n      \"pmids\": [\"36041630\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Human GTF2H4 acts as a positive regulator of partial endothelial-to-mesenchymal transition (EndMT) under hypoxic/ischemic conditions; it collaborates with ERCC3 to co-regulate partial EndMT, and promotes phosphorylation of NCOA3 at serine 1330 (identified by phosphorylation proteomics and confirmed by site-directed mutagenesis), which enhances NCOA3-p65 interaction and transcriptional activation of NF-κB/Snail signaling.\",\n      \"method\": \"Phosphorylation proteomics, site-directed mutagenesis, co-immunoprecipitation (NCOA3-p65 interaction), in vitro and in vivo (ischemic injury) loss/gain-of-function experiments\",\n      \"journal\": \"Innovation (Cambridge (Mass.))\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — phosphoproteomics plus mutagenesis plus co-IP plus in vivo validation, single lab but multiple orthogonal methods\",\n      \"pmids\": [\"38379791\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"GTF2H4 (p52) is an essential subunit of the TFIIH core complex that, through its C-terminal HubA domain, stably incorporates the XPB/Ssl2 DNA translocase into TFIIH to enable promoter opening for RNA pol II transcription and nucleotide excision repair; its C-terminal region also directly contacts and recruits the accessory NER factor p8/Tfb5, while in endothelial cells GTF2H4 additionally promotes NF-κB/Snail-driven partial endothelial-to-mesenchymal transition by facilitating NCOA3 phosphorylation at S1330 and its interaction with p65.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"GTF2H4 (p52) is an essential subunit of the TFIIH core complex required for nucleotide excision repair and RNA polymerase II transcription, established through its yeast ortholog Tfb2 whose C-terminal truncation abolishes NER and confers UV sensitivity [#0, #1]. Its central architectural role is to anchor the XPB/Ssl2 DNA translocase within TFIIH: residues of the C-terminal HubA region are required for stable Ssl2/XPB incorporation, and HubA mutations reduce TFIIH and pol II promoter occupancy and impair gene induction, with the Tfb6 factor genetically modulating Ssl2 dissociation [#5]. The same C-terminal region directly and selectively contacts the accessory NER subunit Tfb5/p8 — an interaction resolved at atomic resolution and functionally required for efficient repair — thereby bridging the XPB helicase to Tfb5; this domain also binds nucleic acids, and Tfb5 binding displaces the bound nucleic acid [#2, #3, #4]. Beyond its core transcription/repair role, GTF2H4 acts in endothelial cells as a positive regulator of partial endothelial-to-mesenchymal transition under ischemic conditions, where, together with ERCC3, it promotes NCOA3 phosphorylation at serine 1330 to enhance NCOA3–p65 interaction and NF-\\u03baB/Snail signaling [#6].\",\n  \"teleology\": [\n    {\n      \"year\": 1997,\n      \"claim\": \"Established that the p52 subunit is an essential TFIIH component whose C-terminus is specifically required for NER, defining its functional importance and the human-yeast orthology.\",\n      \"evidence\": \"Yeast deletion/truncation genetics with UV sensitivity and cell-extract NER complementation by purified TFIIH, plus sequence alignment to human p52\",\n      \"pmids\": [\"9235928\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve which TFIIH interactions the C-terminus mediates\", \"No structural or biochemical mechanism for the repair defect\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Identified a direct, selective Tfb2/p52 contact with the accessory subunit Tfb5/p8, localizing the repair-critical function to a specific interaction interface.\",\n      \"evidence\": \"Co-IP, domain deletion mapping, and UV/NER complementation in yeast extracts\",\n      \"pmids\": [\"17215295\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of the interface unknown\", \"Effect on XPB/Ssl2 not addressed\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Showed Tfb2/p52 functions as a bridge linking the Ssl2/XPB helicase to Tfb5, and that the Tfb5-interacting domain binds nucleic acids in a manner reversed by Tfb5, hinting at a regulatory switch.\",\n      \"evidence\": \"Pulldown/co-IP, nucleic-acid binding assays, and genetic epistasis in yeast\",\n      \"pmids\": [\"19897425\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of nucleic-acid displacement during NER not defined\", \"Single-lab biochemistry\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Provided the atomic-resolution basis for the p52-p8 interaction, converting the genetic/biochemical interface into a defined structure.\",\n      \"evidence\": \"X-ray crystallography of Tfb5 with the Tfb2 C-terminal region at 1.7 \\u00c5\",\n      \"pmids\": [\"20606254\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structure of full-length p52 within intact TFIIH not resolved\", \"Does not capture XPB-bound state\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Defined the HubA region as the determinant for stable XPB/Ssl2 incorporation into TFIIH and linked this to promoter occupancy and transcriptional activation, mechanistically connecting p52 architecture to function in both yeast and human cells.\",\n      \"evidence\": \"Systematic mutagenesis, XL-MS, cryo-EM, co-IP in yeast and human cells, ChIP, and gene expression assays\",\n      \"pmids\": [\"36041630\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Role of Tfb6-equivalent regulation in human cells not established\", \"Dynamics of Ssl2 association/dissociation during the catalytic cycle incomplete\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Extended GTF2H4 function beyond core transcription/repair to a signaling role in endothelial cells, identifying an NCOA3 phosphorylation event that drives NF-\\u03baB/Snail-mediated partial EndMT.\",\n      \"evidence\": \"Phosphoproteomics, site-directed mutagenesis, co-IP, and in vitro/in vivo ischemic injury loss/gain-of-function\",\n      \"pmids\": [\"38379791\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether GTF2H4 directly phosphorylates NCOA3 or acts via an associated kinase is unresolved\", \"Relationship between TFIIH core function and the EndMT role not mechanistically connected\", \"Single-lab finding\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How GTF2H4's canonical TFIIH-scaffolding role mechanistically intersects with its context-specific EndMT signaling function remains unknown.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structure of human GTF2H4 in the EndMT signaling context\", \"Kinase responsible for NCOA3 S1330 phosphorylation unidentified\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003723\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [0, 5]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [3, 5]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [5]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [0, 2]},\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [5]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [6]}\n    ],\n    \"complexes\": [\"TFIIH\"],\n    \"partners\": [\"ERCC3\", \"GTF2H5\", \"NCOA3\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"tie","faith_supported":4,"faith_total":4,"faith_pct":100.0}}