{"gene":"TAF2","run_date":"2026-04-28T21:42:58","timeline":{"discoveries":[{"year":1994,"finding":"Drosophila TAFII150 (TAF2 ortholog) binds directly to TBP and TAFII250, and binds specifically to DNA sequences overlapping the transcription start site, demonstrating that it contributes to TFIID interactions with an extended region of the core promoter including the initiator element.","method":"Biochemical characterization, direct DNA binding studies with purified recombinant protein, in vivo co-association assays","journal":"Science","confidence":"High","confidence_rationale":"Tier 1–2 — multiple orthogonal biochemical methods (direct binding, DNA footprinting, co-association) in a foundational paper with 199 citations","pmids":["8178153"],"is_preprint":false},{"year":1998,"finding":"Human TAFII150 (TAF2/CIF150) is a tightly associated component of human TFIID and is required for initiator-dependent transcription; however, TAFII150-containing TFIID alone is insufficient for full initiator-directed transcription, requiring additional novel cofactors (TICs) and TFIIA.","method":"cDNA cloning, in vitro transcription reconstitution with purified factors, promoter-dependent transcription assays","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 1–2 — in vitro reconstitution with purified components, multiple promoter contexts tested","pmids":["9774672"],"is_preprint":false},{"year":1998,"finding":"Human CIF150 (TAF2) directly and specifically interacts with hTAFII135 in vitro, mediates TFIID-dependent initiator activity in a complementation assay, and stabilizes TFIID binding to the core promoter.","method":"Molecular cloning, in vitro binding assays, complementation assay, TFIID-promoter binding assay","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 1–2 — direct binding assays plus functional complementation with multiple orthogonal readouts","pmids":["9418870"],"is_preprint":false},{"year":1999,"finding":"Human CIF150 (hTAFII150/TAF2) is required for cell cycle progression through the G2/M transition; its functional knockout leads to G2/M arrest, and it directly stimulates cyclin B1 and cyclin A transcription by binding a defined consensus sequence in the cyclin B1 core promoter.","method":"Transient functional knockout, gel filtration, PCR display analysis, cotransfection and in vitro transcription assays, consensus binding site definition","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 2 — loss-of-function with specific phenotypic readout combined with in vitro transcription assay and defined promoter element","pmids":["10409744"],"is_preprint":false},{"year":2009,"finding":"The Taf2p subunit of yeast TFIID is positioned in the vicinity of Taf1p and TBP within the TFIID structure, as determined by electron tomography and cryo-EM comparison of Taf2p-containing versus Taf2p-depleted complexes, confirmed by immunolabeling.","method":"Electron tomography, cryo-EM single-particle analysis, immunolabeling with subunit-specific antibody","journal":"Structure","confidence":"High","confidence_rationale":"Tier 1 — structural study with multiple orthogonal imaging methods and antibody confirmation","pmids":["19278651"],"is_preprint":false},{"year":2009,"finding":"In yeast, taf1 mutation selectively reduces Taf2 occupancy at promoters genome-wide, and TFIID adopts different conformations at different promoter classes (RPGs vs. non-RPGs), with SAGA and TFIID co-localizing on ribosomal protein gene promoters.","method":"ChIP-chip genome-wide localization, conventional and sequential ChIP","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 2 — genome-wide ChIP with functional inference; single lab study","pmids":["20026583"],"is_preprint":false},{"year":2015,"finding":"TAF2, TAF8, and TAF10 form a heterotrimeric subcomplex in the cytoplasm; TAF8 is the nucleating subunit, TAF8-TAF10 histone fold domains adopt a non-canonical arrangement, and TAF2 binds multiple motifs in the TAF8 C-terminal region, dictating TAF2 incorporation into nuclear core-TFIID, supporting a stepwise cytoplasmic pre-assembly pathway for TFIID.","method":"Native mass spectrometry, X-ray crystallography, subcellular fractionation, interaction mapping","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1 — crystal structure plus native MS and biochemical interaction mapping in one study with multiple orthogonal methods","pmids":["25586196"],"is_preprint":false},{"year":2016,"finding":"The C-terminal region of yeast Taf2 mediates direct interaction with Taf14, and this interaction is required for stable incorporation of Taf14 into the TFIID complex; a Taf2-ΔC separation-of-function variant that cannot bind Taf14 still assembles into TFIID but produces Taf14-devoid TFIID.","method":"Systematic site-directed mutagenesis, genetic suppression analysis, co-immunoprecipitation, in vitro direct binding, purified mutant TFIID complex analysis","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 — mutagenesis combined with in vitro binding, genetic epistasis, and biochemical purification","pmids":["27587401"],"is_preprint":false},{"year":2021,"finding":"Four distinct proline-rich regions of TAF8, each individually required for TAF2 interaction in TFIID lobe C, were identified; CRISPR/Cas9 editing showed that the TAF8 domain interacting with the 5TAF core and the TAF8 proline-rich domain interacting with TAF2 are both required for mouse embryonic stem cell survival.","method":"In vitro lobe assembly assays, interaction mapping, CRISPR/Cas9 gene editing, ESC viability assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 — in vitro reconstitution combined with CRISPR KO and defined cellular phenotype","pmids":["34634302"],"is_preprint":false},{"year":2022,"finding":"The YEATS and ET domains of yeast Taf14 bind the C-terminal tail of Taf2; Taf2 binding triggers a conformational rearrangement in Taf14 that releases its autoinhibited linker region, enabling Taf14 to bind DNA and nucleosomes; this Taf2-mediated activation of Taf14 DNA-binding is essential for transcriptional regulation in vivo.","method":"X-ray crystallography/structural determination, in vitro DNA and nucleosome binding assays, mutagenesis, in vivo genetic assays","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1 — structure plus in vitro functional assays plus in vivo genetic validation across multiple orthogonal methods","pmids":["35676274"],"is_preprint":false},{"year":2024,"finding":"Human TAF2 is sub-stoichiometrically associated with TFIID and selectively binds to and regulates transcription of a small subset of protein-coding genes including ribosomal protein genes (RPL30, RPL39); TAF2 depletion reduces TBP/TFIID binding at these loci and decreases ribosome assembly and global protein translation.","method":"Co-immunoprecipitation, inducible TAF2 protein degradation system, genome-wide ChIP-seq, ribosome assembly assays, protein translation assays","journal":"Cell death discovery","confidence":"High","confidence_rationale":"Tier 2 — inducible degradation system combined with genome-wide binding analysis and multiple downstream functional readouts","pmids":["38773077"],"is_preprint":false},{"year":2025,"finding":"A conserved intrinsically disordered region (IDR) of TAF2 drives its localization to nuclear speckle condensates independently of other TFIID subunits; the TAF2 IDR interacts specifically with the RNA splicing factor SRRM2 in nuclear speckles; IDR deletion alters alternative splicing events and increases TAF2 promoter association genome-wide, indicating the IDR sequesters TAF2 away from promoters by guiding it to nuclear speckles.","method":"Live imaging, quantitative proximity mass spectrometry, IDR deletion mutant analysis, genome-wide ChIP-seq, alternative splicing analysis","journal":"Cell reports","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods including localization, MS, genome-wide binding, and splicing analysis in one study","pmids":["40287942"],"is_preprint":false},{"year":2025,"finding":"Hepatocyte-specific conditional knockout of Taf2 in mice causes hepatocyte death and compensatory proliferation, establishing TAF2 as required for hepatocyte survival; TAF2 binds to promoters of tumor-promoting genes and non-coding RNAs to regulate their transcription, and its loss creates an inflammatory/fibrotic environment that promotes HCC.","method":"Conditional knockout mouse model, ChIP at target gene promoters, TAF2 knockdown/overexpression in human HCC cells, DEN/diet-induced HCC model","journal":"Hepatology","confidence":"Medium","confidence_rationale":"Tier 2 — in vivo KO with defined phenotype plus ChIP evidence; single lab study","pmids":["40392063"],"is_preprint":false}],"current_model":"TAF2 is a sub-stoichiometric subunit of the TFIID complex that assembles in the cytoplasm as part of a TAF2–TAF8–TAF10 heterotrimer (nucleated by TAF8) before nuclear import; within TFIID, TAF2 binds TBP and core promoter initiator elements to selectively regulate transcription of a subset of genes (including ribosomal protein genes), promotes ribosome assembly and cell viability, and harbors an intrinsically disordered region that drives its condensation into nuclear speckles where it interacts with splicing factors, thereby competing with its promoter association and linking transcription initiation to alternative splicing regulation."},"narrative":{"teleology":[{"year":1994,"claim":"Establishing that the TAF2 ortholog is a core-promoter-contacting TFIID subunit resolved how TFIID recognizes the initiator element downstream of the TATA box.","evidence":"Purified recombinant Drosophila TAFII150 shown to bind TBP, TAFII250, and initiator DNA by direct binding and footprinting assays","pmids":["8178153"],"confidence":"High","gaps":["Binding specificity for mammalian initiator sequences not yet demonstrated","Structural basis of TAF2–DNA interaction unresolved"]},{"year":1998,"claim":"Cloning human TAF2 and reconstituting initiator-dependent transcription showed it is necessary but not sufficient for initiator function, requiring additional cofactors.","evidence":"In vitro transcription reconstitution with purified human TFIID and complementation assays with recombinant CIF150","pmids":["9774672","9418870"],"confidence":"High","gaps":["Identity of required cofactors (TICs) incompletely defined","Whether TAF2 directly contacts initiator DNA in the human system not confirmed"]},{"year":1999,"claim":"Demonstrating that TAF2 loss causes G2/M arrest and that TAF2 directly activates cyclin B1/A transcription revealed gene-selective transcriptional roles for a general factor subunit.","evidence":"Functional knockout in human cells with cell-cycle analysis, plus in vitro transcription and consensus-site binding assays","pmids":["10409744"],"confidence":"High","gaps":["Genome-wide target gene repertoire unknown at this stage","Whether G2/M arrest reflects direct cyclin regulation versus indirect effects unresolved"]},{"year":2009,"claim":"Structural and genomic approaches placed TAF2 near TBP/TAF1 in the TFIID architecture and showed its promoter-class-specific occupancy, particularly at ribosomal protein genes.","evidence":"Cryo-EM/electron tomography of yeast TFIID ± Taf2, genome-wide ChIP-chip in yeast","pmids":["19278651","20026583"],"confidence":"High","gaps":["Atomic-resolution structure of TAF2 within TFIID not available","Mechanism determining differential TAF2 occupancy at RPG vs non-RPG promoters unclear"]},{"year":2015,"claim":"Discovery that TAF2–TAF8–TAF10 form a cytoplasmic heterotrimer nucleated by TAF8 established a stepwise, spatially regulated TFIID assembly pathway.","evidence":"X-ray crystallography, native mass spectrometry, and subcellular fractionation of human TAF2–TAF8–TAF10","pmids":["25586196"],"confidence":"High","gaps":["How the trimer is imported into the nucleus and handed off to nuclear core-TFIID not resolved","Regulation of cytoplasmic assembly not characterized"]},{"year":2016,"claim":"Identifying a direct TAF2 C-terminus–Taf14 interaction required for Taf14 incorporation into TFIID revealed TAF2 as a platform for accessory subunit recruitment.","evidence":"Co-IP, in vitro binding, and separation-of-function Taf2-ΔC mutant in yeast","pmids":["27587401"],"confidence":"High","gaps":["Whether an analogous interaction exists for a human TAF14 homolog unknown","Functional consequences of Taf14-devoid TFIID on transcription not fully explored"]},{"year":2021,"claim":"Mapping four proline-rich TAF8 regions each required for TAF2 binding and showing both are essential for ESC viability tied TFIID lobe C assembly to cell survival.","evidence":"In vitro lobe reconstitution and CRISPR/Cas9 editing in mouse embryonic stem cells","pmids":["34634302"],"confidence":"High","gaps":["Whether viability defect is due specifically to TAF2 loss from TFIID or broader lobe C disruption not separated"]},{"year":2022,"claim":"Showing that Taf2 binding allosterically activates Taf14 DNA/nucleosome binding revealed a conformational switch mechanism linking TFIID subunit interactions to chromatin engagement.","evidence":"X-ray crystallography of Taf14 domains bound to Taf2 tail, in vitro DNA/nucleosome binding, and in vivo yeast genetics","pmids":["35676274"],"confidence":"High","gaps":["Structural basis of the full Taf2–Taf14 complex within intact TFIID not determined","Whether this allosteric mechanism operates at all promoter classes unknown"]},{"year":2024,"claim":"Inducible degradation of TAF2 in human cells demonstrated its sub-stoichiometric TFIID association and selective requirement for ribosomal protein gene transcription, ribosome assembly, and translation.","evidence":"Inducible TAF2 degradation, ChIP-seq, ribosome assembly and translation assays in human cells","pmids":["38773077"],"confidence":"High","gaps":["Mechanism determining sub-stoichiometric TAF2 incorporation into TFIID unknown","Whether TAF2 directly contacts ribosomal protein gene promoter elements or acts via co-regulators unclear"]},{"year":2025,"claim":"Discovering that TAF2's intrinsically disordered region drives nuclear speckle localization via SRRM2 interaction, competing with promoter association and modulating alternative splicing, established a TFIID-independent role linking transcription initiation machinery to splicing regulation.","evidence":"Live imaging, proximity MS, IDR deletion mutant ChIP-seq, and alternative splicing analysis in human cells","pmids":["40287942"],"confidence":"High","gaps":["Whether IDR-mediated speckle localization is regulated by post-translational modifications unknown","Direct RNA targets affected by TAF2 speckle sequestration not catalogued","Whether IDR-dependent splicing changes are mediated through SRRM2 or additional speckle factors not resolved"]},{"year":2025,"claim":"Hepatocyte-specific Taf2 knockout showed TAF2 is essential for hepatocyte survival and that its loss creates an inflammatory/fibrotic environment promoting hepatocellular carcinoma.","evidence":"Conditional Taf2 knockout mouse, ChIP at target promoters, DEN/diet-induced HCC model","pmids":["40392063"],"confidence":"Medium","gaps":["Single lab study; independent replication needed","Whether HCC promotion reflects loss of TAF2 transcriptional function, speckle function, or both not distinguished","Direct TAF2 target genes driving the tumor-suppressive effect not fully defined"]},{"year":null,"claim":"Key open questions include how TAF2 sub-stoichiometry within TFIID is regulated, the atomic structure of TAF2 in human holo-TFIID, whether post-translational modifications control the balance between promoter-bound and speckle-localized TAF2, and the full scope of TAF2-dependent alternative splicing events.","evidence":"","pmids":[],"confidence":"Low","gaps":["No high-resolution structure of human TAF2 within holo-TFIID","Regulatory signals controlling TAF2 partitioning between TFIID and nuclear speckles unknown","Genome-wide identification of TAF2-dependent splicing events incomplete"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003677","term_label":"DNA binding","supporting_discovery_ids":[0,3]},{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[1,3,10,12]},{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[6,8]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[6,10,11]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[6]},{"term_id":"GO:0005654","term_label":"nucleoplasm","supporting_discovery_ids":[11]}],"pathway":[{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[0,1,2,3,10,12]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[10]},{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[11]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[3]}],"complexes":["TFIID","TAF2-TAF8-TAF10 heterotrimer"],"partners":["TAF1","TBP","TAF8","TAF10","TAF14","SRRM2"],"other_free_text":[]},"mechanistic_narrative":"TAF2 is a subunit of the general transcription factor TFIID that selectively regulates transcription of a subset of protein-coding genes, coupling core promoter recognition to ribosome biogenesis and mRNA splicing. TAF2 binds TBP, TAF1/TAFII250, and DNA sequences overlapping the transcription start site including the initiator element, stabilizing TFIID at core promoters and enabling initiator-dependent transcription [PMID:8178153, PMID:9774672, PMID:9418870]. It assembles in the cytoplasm as part of a TAF2–TAF8–TAF10 heterotrimer nucleated by TAF8 before nuclear import, and is sub-stoichiometrically incorporated into TFIID where it selectively occupies promoters of ribosomal protein genes and other targets; its depletion reduces TBP occupancy at these loci, impairs ribosome assembly and global translation, and causes hepatocyte death in vivo [PMID:25586196, PMID:38773077, PMID:40392063]. A conserved intrinsically disordered region drives TAF2 localization to nuclear speckle condensates through interaction with the splicing factor SRRM2, sequestering TAF2 away from promoters and modulating alternative splicing, thereby linking transcription initiation to post-transcriptional RNA processing [PMID:40287942]."},"prefetch_data":{"uniprot":{"accession":"Q6P1X5","full_name":"Transcription initiation factor TFIID subunit 2","aliases":["150 kDa cofactor of initiator function","RNA polymerase II TBP-associated factor subunit B","TBP-associated factor 150 kDa","Transcription initiation factor TFIID 150 kDa subunit","TAF(II)150","TAFII-150","TAFII150"],"length_aa":1199,"mass_kda":137.0,"function":"The TFIID basal transcription factor complex plays a major role in the initiation of RNA polymerase II (Pol II)-dependent transcription (PubMed:33795473). TFIID recognizes and binds promoters with or without a TATA box via its subunit TBP, a TATA-box-binding protein, and promotes assembly of the pre-initiation complex (PIC) (PubMed:33795473). The TFIID complex consists of TBP and TBP-associated factors (TAFs), including TAF1, TAF2, TAF3, TAF4, TAF5, TAF6, TAF7, TAF8, TAF9, TAF10, TAF11, TAF12 and TAF13 (PubMed:33795473, PubMed:9418870, PubMed:9774672). TAF2 forms a promoter DNA binding subcomplex of TFIID, together with TAF7 and TAF1 (PubMed:33795473, PubMed:9774672)","subcellular_location":"Nucleus","url":"https://www.uniprot.org/uniprotkb/Q6P1X5/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/TAF2","classification":"Common Essential","n_dependent_lines":1047,"n_total_lines":1208,"dependency_fraction":0.8667218543046358},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/TAF2","total_profiled":1310},"omim":[{"mim_id":"615599","title":"NEURODEVELOPMENTAL DISORDER WITH FEEDING DIFFICULTIES, THIN CORPUS CALLOSUM, AND FOOT DEFORMITY; NEDFCF","url":"https://www.omim.org/entry/615599"},{"mim_id":"604912","title":"TAF2 RNA POLYMERASE II, TATA BOX-BINDING PROTEIN-ASSOCIATED FACTOR, 150-KD; TAF2","url":"https://www.omim.org/entry/604912"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/TAF2"},"hgnc":{"alias_symbol":["TAFII150","CIF150"],"prev_symbol":["TAF2B"]},"alphafold":{"accession":"Q6P1X5","domains":[{"cath_id":"2.60.40.1730","chopping":"23-88_126-254","consensus_level":"medium","plddt":88.5566,"start":23,"end":254},{"cath_id":"1.10.390","chopping":"370-524","consensus_level":"medium","plddt":81.5456,"start":370,"end":524},{"cath_id":"2.60.40","chopping":"530-637","consensus_level":"medium","plddt":81.1756,"start":530,"end":637}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6P1X5","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q6P1X5-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q6P1X5-F1-predicted_aligned_error_v6.png","plddt_mean":73.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=TAF2","jax_strain_url":"https://www.jax.org/strain/search?query=TAF2"},"sequence":{"accession":"Q6P1X5","fasta_url":"https://rest.uniprot.org/uniprotkb/Q6P1X5.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q6P1X5/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6P1X5"}},"corpus_meta":[{"pmid":"8178153","id":"PMC_8178153","title":"Drosophila TAFII150: similarity to yeast gene TSM-1 and specific binding to core promoter DNA.","date":"1994","source":"Science (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/8178153","citation_count":199,"is_preprint":false},{"pmid":"25586196","id":"PMC_25586196","title":"Cytoplasmic TAF2-TAF8-TAF10 complex provides evidence for nuclear holo-TFIID assembly from preformed submodules.","date":"2015","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/25586196","citation_count":80,"is_preprint":false},{"pmid":"9774672","id":"PMC_9774672","title":"Novel cofactors and TFIIA mediate functional core promoter selectivity by the human TAFII150-containing TFIID complex.","date":"1998","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/9774672","citation_count":62,"is_preprint":false},{"pmid":"9418870","id":"PMC_9418870","title":"CIF150, a human cofactor for transcription factor IID-dependent initiator function.","date":"1998","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/9418870","citation_count":58,"is_preprint":false},{"pmid":"19278651","id":"PMC_19278651","title":"Mapping the initiator binding Taf2 subunit in the structure of hydrated yeast TFIID.","date":"2009","source":"Structure (London, England : 1993)","url":"https://pubmed.ncbi.nlm.nih.gov/19278651","citation_count":37,"is_preprint":false},{"pmid":"24084144","id":"PMC_24084144","title":"Microcephaly thin corpus callosum intellectual disability syndrome caused by mutated TAF2.","date":"2013","source":"Pediatric neurology","url":"https://pubmed.ncbi.nlm.nih.gov/24084144","citation_count":31,"is_preprint":false},{"pmid":"10409744","id":"PMC_10409744","title":"Human transcription factor hTAF(II)150 (CIF150) is involved in transcriptional regulation of cell cycle progression.","date":"1999","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/10409744","citation_count":29,"is_preprint":false},{"pmid":"27587401","id":"PMC_27587401","title":"The C Terminus of the RNA Polymerase II Transcription Factor IID (TFIID) Subunit Taf2 Mediates Stable Association of Subunit Taf14 into the Yeast TFIID Complex.","date":"2016","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/27587401","citation_count":15,"is_preprint":false},{"pmid":"20026583","id":"PMC_20026583","title":"Genome-wide localization analysis of a complete set of Tafs reveals a specific effect of the taf1 mutation on Taf2 occupancy and provides indirect evidence for different TFIID conformations at different promoters.","date":"2009","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/20026583","citation_count":12,"is_preprint":false},{"pmid":"35676274","id":"PMC_35676274","title":"Taf2 mediates DNA binding of Taf14.","date":"2022","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/35676274","citation_count":9,"is_preprint":false},{"pmid":"34634302","id":"PMC_34634302","title":"TAF8 regions important for TFIID lobe B assembly or for TAF2 interactions are required for embryonic stem cell survival.","date":"2021","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/34634302","citation_count":6,"is_preprint":false},{"pmid":"34474177","id":"PMC_34474177","title":"Phenotype associated with TAF2 biallelic mutations: A clinical description of four individuals and review of the literature.","date":"2021","source":"European journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/34474177","citation_count":5,"is_preprint":false},{"pmid":"38773077","id":"PMC_38773077","title":"TAF2, within the TFIID complex, regulates the expression of a subset of protein-coding genes.","date":"2024","source":"Cell death discovery","url":"https://pubmed.ncbi.nlm.nih.gov/38773077","citation_count":4,"is_preprint":false},{"pmid":"40287942","id":"PMC_40287942","title":"TAF2 condensation in nuclear speckles links basal transcription factor TFIID to RNA splicing factors.","date":"2025","source":"Cell reports","url":"https://pubmed.ncbi.nlm.nih.gov/40287942","citation_count":3,"is_preprint":false},{"pmid":"40392063","id":"PMC_40392063","title":"TATA-box binding protein-associated factor 2 (TAF2) in hepatocyte survival and tumorigenesis.","date":"2025","source":"Hepatology (Baltimore, Md.)","url":"https://pubmed.ncbi.nlm.nih.gov/40392063","citation_count":1,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8210,"output_tokens":3027,"usd":0.035018},"stage2":{"model":"claude-opus-4-6","input_tokens":6404,"output_tokens":2884,"usd":0.15618},"total_usd":0.191198,"stage1_batch_id":"msgbatch_01RPbVc9PDH9zQmYK5Hs6srm","stage2_batch_id":"msgbatch_01JVbVLzeKN2yVrsGp3zC8aM","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1994,\n      \"finding\": \"Drosophila TAFII150 (TAF2 ortholog) binds directly to TBP and TAFII250, and binds specifically to DNA sequences overlapping the transcription start site, demonstrating that it contributes to TFIID interactions with an extended region of the core promoter including the initiator element.\",\n      \"method\": \"Biochemical characterization, direct DNA binding studies with purified recombinant protein, in vivo co-association assays\",\n      \"journal\": \"Science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — multiple orthogonal biochemical methods (direct binding, DNA footprinting, co-association) in a foundational paper with 199 citations\",\n      \"pmids\": [\"8178153\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"Human TAFII150 (TAF2/CIF150) is a tightly associated component of human TFIID and is required for initiator-dependent transcription; however, TAFII150-containing TFIID alone is insufficient for full initiator-directed transcription, requiring additional novel cofactors (TICs) and TFIIA.\",\n      \"method\": \"cDNA cloning, in vitro transcription reconstitution with purified factors, promoter-dependent transcription assays\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — in vitro reconstitution with purified components, multiple promoter contexts tested\",\n      \"pmids\": [\"9774672\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"Human CIF150 (TAF2) directly and specifically interacts with hTAFII135 in vitro, mediates TFIID-dependent initiator activity in a complementation assay, and stabilizes TFIID binding to the core promoter.\",\n      \"method\": \"Molecular cloning, in vitro binding assays, complementation assay, TFIID-promoter binding assay\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — direct binding assays plus functional complementation with multiple orthogonal readouts\",\n      \"pmids\": [\"9418870\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"Human CIF150 (hTAFII150/TAF2) is required for cell cycle progression through the G2/M transition; its functional knockout leads to G2/M arrest, and it directly stimulates cyclin B1 and cyclin A transcription by binding a defined consensus sequence in the cyclin B1 core promoter.\",\n      \"method\": \"Transient functional knockout, gel filtration, PCR display analysis, cotransfection and in vitro transcription assays, consensus binding site definition\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — loss-of-function with specific phenotypic readout combined with in vitro transcription assay and defined promoter element\",\n      \"pmids\": [\"10409744\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"The Taf2p subunit of yeast TFIID is positioned in the vicinity of Taf1p and TBP within the TFIID structure, as determined by electron tomography and cryo-EM comparison of Taf2p-containing versus Taf2p-depleted complexes, confirmed by immunolabeling.\",\n      \"method\": \"Electron tomography, cryo-EM single-particle analysis, immunolabeling with subunit-specific antibody\",\n      \"journal\": \"Structure\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — structural study with multiple orthogonal imaging methods and antibody confirmation\",\n      \"pmids\": [\"19278651\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"In yeast, taf1 mutation selectively reduces Taf2 occupancy at promoters genome-wide, and TFIID adopts different conformations at different promoter classes (RPGs vs. non-RPGs), with SAGA and TFIID co-localizing on ribosomal protein gene promoters.\",\n      \"method\": \"ChIP-chip genome-wide localization, conventional and sequential ChIP\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genome-wide ChIP with functional inference; single lab study\",\n      \"pmids\": [\"20026583\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"TAF2, TAF8, and TAF10 form a heterotrimeric subcomplex in the cytoplasm; TAF8 is the nucleating subunit, TAF8-TAF10 histone fold domains adopt a non-canonical arrangement, and TAF2 binds multiple motifs in the TAF8 C-terminal region, dictating TAF2 incorporation into nuclear core-TFIID, supporting a stepwise cytoplasmic pre-assembly pathway for TFIID.\",\n      \"method\": \"Native mass spectrometry, X-ray crystallography, subcellular fractionation, interaction mapping\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — crystal structure plus native MS and biochemical interaction mapping in one study with multiple orthogonal methods\",\n      \"pmids\": [\"25586196\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"The C-terminal region of yeast Taf2 mediates direct interaction with Taf14, and this interaction is required for stable incorporation of Taf14 into the TFIID complex; a Taf2-ΔC separation-of-function variant that cannot bind Taf14 still assembles into TFIID but produces Taf14-devoid TFIID.\",\n      \"method\": \"Systematic site-directed mutagenesis, genetic suppression analysis, co-immunoprecipitation, in vitro direct binding, purified mutant TFIID complex analysis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — mutagenesis combined with in vitro binding, genetic epistasis, and biochemical purification\",\n      \"pmids\": [\"27587401\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Four distinct proline-rich regions of TAF8, each individually required for TAF2 interaction in TFIID lobe C, were identified; CRISPR/Cas9 editing showed that the TAF8 domain interacting with the 5TAF core and the TAF8 proline-rich domain interacting with TAF2 are both required for mouse embryonic stem cell survival.\",\n      \"method\": \"In vitro lobe assembly assays, interaction mapping, CRISPR/Cas9 gene editing, ESC viability assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — in vitro reconstitution combined with CRISPR KO and defined cellular phenotype\",\n      \"pmids\": [\"34634302\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"The YEATS and ET domains of yeast Taf14 bind the C-terminal tail of Taf2; Taf2 binding triggers a conformational rearrangement in Taf14 that releases its autoinhibited linker region, enabling Taf14 to bind DNA and nucleosomes; this Taf2-mediated activation of Taf14 DNA-binding is essential for transcriptional regulation in vivo.\",\n      \"method\": \"X-ray crystallography/structural determination, in vitro DNA and nucleosome binding assays, mutagenesis, in vivo genetic assays\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — structure plus in vitro functional assays plus in vivo genetic validation across multiple orthogonal methods\",\n      \"pmids\": [\"35676274\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Human TAF2 is sub-stoichiometrically associated with TFIID and selectively binds to and regulates transcription of a small subset of protein-coding genes including ribosomal protein genes (RPL30, RPL39); TAF2 depletion reduces TBP/TFIID binding at these loci and decreases ribosome assembly and global protein translation.\",\n      \"method\": \"Co-immunoprecipitation, inducible TAF2 protein degradation system, genome-wide ChIP-seq, ribosome assembly assays, protein translation assays\",\n      \"journal\": \"Cell death discovery\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — inducible degradation system combined with genome-wide binding analysis and multiple downstream functional readouts\",\n      \"pmids\": [\"38773077\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"A conserved intrinsically disordered region (IDR) of TAF2 drives its localization to nuclear speckle condensates independently of other TFIID subunits; the TAF2 IDR interacts specifically with the RNA splicing factor SRRM2 in nuclear speckles; IDR deletion alters alternative splicing events and increases TAF2 promoter association genome-wide, indicating the IDR sequesters TAF2 away from promoters by guiding it to nuclear speckles.\",\n      \"method\": \"Live imaging, quantitative proximity mass spectrometry, IDR deletion mutant analysis, genome-wide ChIP-seq, alternative splicing analysis\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods including localization, MS, genome-wide binding, and splicing analysis in one study\",\n      \"pmids\": [\"40287942\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Hepatocyte-specific conditional knockout of Taf2 in mice causes hepatocyte death and compensatory proliferation, establishing TAF2 as required for hepatocyte survival; TAF2 binds to promoters of tumor-promoting genes and non-coding RNAs to regulate their transcription, and its loss creates an inflammatory/fibrotic environment that promotes HCC.\",\n      \"method\": \"Conditional knockout mouse model, ChIP at target gene promoters, TAF2 knockdown/overexpression in human HCC cells, DEN/diet-induced HCC model\",\n      \"journal\": \"Hepatology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vivo KO with defined phenotype plus ChIP evidence; single lab study\",\n      \"pmids\": [\"40392063\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"TAF2 is a sub-stoichiometric subunit of the TFIID complex that assembles in the cytoplasm as part of a TAF2–TAF8–TAF10 heterotrimer (nucleated by TAF8) before nuclear import; within TFIID, TAF2 binds TBP and core promoter initiator elements to selectively regulate transcription of a subset of genes (including ribosomal protein genes), promotes ribosome assembly and cell viability, and harbors an intrinsically disordered region that drives its condensation into nuclear speckles where it interacts with splicing factors, thereby competing with its promoter association and linking transcription initiation to alternative splicing regulation.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"TAF2 is a subunit of the general transcription factor TFIID that selectively regulates transcription of a subset of protein-coding genes, coupling core promoter recognition to ribosome biogenesis and mRNA splicing. TAF2 binds TBP, TAF1/TAFII250, and DNA sequences overlapping the transcription start site including the initiator element, stabilizing TFIID at core promoters and enabling initiator-dependent transcription [PMID:8178153, PMID:9774672, PMID:9418870]. It assembles in the cytoplasm as part of a TAF2–TAF8–TAF10 heterotrimer nucleated by TAF8 before nuclear import, and is sub-stoichiometrically incorporated into TFIID where it selectively occupies promoters of ribosomal protein genes and other targets; its depletion reduces TBP occupancy at these loci, impairs ribosome assembly and global translation, and causes hepatocyte death in vivo [PMID:25586196, PMID:38773077, PMID:40392063]. A conserved intrinsically disordered region drives TAF2 localization to nuclear speckle condensates through interaction with the splicing factor SRRM2, sequestering TAF2 away from promoters and modulating alternative splicing, thereby linking transcription initiation to post-transcriptional RNA processing [PMID:40287942].\",\n  \"teleology\": [\n    {\n      \"year\": 1994,\n      \"claim\": \"Establishing that the TAF2 ortholog is a core-promoter-contacting TFIID subunit resolved how TFIID recognizes the initiator element downstream of the TATA box.\",\n      \"evidence\": \"Purified recombinant Drosophila TAFII150 shown to bind TBP, TAFII250, and initiator DNA by direct binding and footprinting assays\",\n      \"pmids\": [\"8178153\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Binding specificity for mammalian initiator sequences not yet demonstrated\", \"Structural basis of TAF2–DNA interaction unresolved\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Cloning human TAF2 and reconstituting initiator-dependent transcription showed it is necessary but not sufficient for initiator function, requiring additional cofactors.\",\n      \"evidence\": \"In vitro transcription reconstitution with purified human TFIID and complementation assays with recombinant CIF150\",\n      \"pmids\": [\"9774672\", \"9418870\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of required cofactors (TICs) incompletely defined\", \"Whether TAF2 directly contacts initiator DNA in the human system not confirmed\"]\n    },\n    {\n      \"year\": 1999,\n      \"claim\": \"Demonstrating that TAF2 loss causes G2/M arrest and that TAF2 directly activates cyclin B1/A transcription revealed gene-selective transcriptional roles for a general factor subunit.\",\n      \"evidence\": \"Functional knockout in human cells with cell-cycle analysis, plus in vitro transcription and consensus-site binding assays\",\n      \"pmids\": [\"10409744\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Genome-wide target gene repertoire unknown at this stage\", \"Whether G2/M arrest reflects direct cyclin regulation versus indirect effects unresolved\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Structural and genomic approaches placed TAF2 near TBP/TAF1 in the TFIID architecture and showed its promoter-class-specific occupancy, particularly at ribosomal protein genes.\",\n      \"evidence\": \"Cryo-EM/electron tomography of yeast TFIID ± Taf2, genome-wide ChIP-chip in yeast\",\n      \"pmids\": [\"19278651\", \"20026583\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Atomic-resolution structure of TAF2 within TFIID not available\", \"Mechanism determining differential TAF2 occupancy at RPG vs non-RPG promoters unclear\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Discovery that TAF2–TAF8–TAF10 form a cytoplasmic heterotrimer nucleated by TAF8 established a stepwise, spatially regulated TFIID assembly pathway.\",\n      \"evidence\": \"X-ray crystallography, native mass spectrometry, and subcellular fractionation of human TAF2–TAF8–TAF10\",\n      \"pmids\": [\"25586196\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How the trimer is imported into the nucleus and handed off to nuclear core-TFIID not resolved\", \"Regulation of cytoplasmic assembly not characterized\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Identifying a direct TAF2 C-terminus–Taf14 interaction required for Taf14 incorporation into TFIID revealed TAF2 as a platform for accessory subunit recruitment.\",\n      \"evidence\": \"Co-IP, in vitro binding, and separation-of-function Taf2-ΔC mutant in yeast\",\n      \"pmids\": [\"27587401\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether an analogous interaction exists for a human TAF14 homolog unknown\", \"Functional consequences of Taf14-devoid TFIID on transcription not fully explored\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Mapping four proline-rich TAF8 regions each required for TAF2 binding and showing both are essential for ESC viability tied TFIID lobe C assembly to cell survival.\",\n      \"evidence\": \"In vitro lobe reconstitution and CRISPR/Cas9 editing in mouse embryonic stem cells\",\n      \"pmids\": [\"34634302\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether viability defect is due specifically to TAF2 loss from TFIID or broader lobe C disruption not separated\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Showing that Taf2 binding allosterically activates Taf14 DNA/nucleosome binding revealed a conformational switch mechanism linking TFIID subunit interactions to chromatin engagement.\",\n      \"evidence\": \"X-ray crystallography of Taf14 domains bound to Taf2 tail, in vitro DNA/nucleosome binding, and in vivo yeast genetics\",\n      \"pmids\": [\"35676274\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of the full Taf2–Taf14 complex within intact TFIID not determined\", \"Whether this allosteric mechanism operates at all promoter classes unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Inducible degradation of TAF2 in human cells demonstrated its sub-stoichiometric TFIID association and selective requirement for ribosomal protein gene transcription, ribosome assembly, and translation.\",\n      \"evidence\": \"Inducible TAF2 degradation, ChIP-seq, ribosome assembly and translation assays in human cells\",\n      \"pmids\": [\"38773077\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism determining sub-stoichiometric TAF2 incorporation into TFIID unknown\", \"Whether TAF2 directly contacts ribosomal protein gene promoter elements or acts via co-regulators unclear\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Discovering that TAF2's intrinsically disordered region drives nuclear speckle localization via SRRM2 interaction, competing with promoter association and modulating alternative splicing, established a TFIID-independent role linking transcription initiation machinery to splicing regulation.\",\n      \"evidence\": \"Live imaging, proximity MS, IDR deletion mutant ChIP-seq, and alternative splicing analysis in human cells\",\n      \"pmids\": [\"40287942\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether IDR-mediated speckle localization is regulated by post-translational modifications unknown\", \"Direct RNA targets affected by TAF2 speckle sequestration not catalogued\", \"Whether IDR-dependent splicing changes are mediated through SRRM2 or additional speckle factors not resolved\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Hepatocyte-specific Taf2 knockout showed TAF2 is essential for hepatocyte survival and that its loss creates an inflammatory/fibrotic environment promoting hepatocellular carcinoma.\",\n      \"evidence\": \"Conditional Taf2 knockout mouse, ChIP at target promoters, DEN/diet-induced HCC model\",\n      \"pmids\": [\"40392063\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab study; independent replication needed\", \"Whether HCC promotion reflects loss of TAF2 transcriptional function, speckle function, or both not distinguished\", \"Direct TAF2 target genes driving the tumor-suppressive effect not fully defined\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Key open questions include how TAF2 sub-stoichiometry within TFIID is regulated, the atomic structure of TAF2 in human holo-TFIID, whether post-translational modifications control the balance between promoter-bound and speckle-localized TAF2, and the full scope of TAF2-dependent alternative splicing events.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No high-resolution structure of human TAF2 within holo-TFIID\", \"Regulatory signals controlling TAF2 partitioning between TFIID and nuclear speckles unknown\", \"Genome-wide identification of TAF2-dependent splicing events incomplete\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003677\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [1, 3, 10, 12]},\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [6, 8]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [6, 10, 11]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [6]},\n      {\"term_id\": \"GO:0005654\", \"supporting_discovery_ids\": [11]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [0, 1, 2, 3, 10, 12]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [10]},\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [11]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"complexes\": [\n      \"TFIID\",\n      \"TAF2-TAF8-TAF10 heterotrimer\"\n    ],\n    \"partners\": [\n      \"TAF1\",\n      \"TBP\",\n      \"TAF8\",\n      \"TAF10\",\n      \"TAF14\",\n      \"SRRM2\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}