{"gene":"SGF29","run_date":"2026-04-28T20:42:07","timeline":{"discoveries":[{"year":2011,"finding":"Crystal structures of the tandem Tudor domains of S. cerevisiae and human SGF29 reveal that these domains selectively bind H3K4me2/3 marks; the tandem Tudor domains pack face-to-face with one pocket accommodating H3A1 and the other accommodating K4me2/3, and this interaction recruits the SAGA complex to target sites to mediate histone H3 acetylation in vivo.","method":"Crystal structure determination, histone peptide binding assays, in vitro functional assays, and in vivo chromatin recruitment/acetylation assays","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 — crystal structures with functional validation by in vitro and in vivo assays, high citation count indicating replication","pmids":["21685874"],"is_preprint":false},{"year":2010,"finding":"The tandem Tudor domain at the C-terminus of S. cerevisiae Sgf29 was crystallized and diffracted to 1.92 Å resolution, establishing the structural basis for subsequent functional studies.","method":"X-ray crystallography (hanging-drop vapour-diffusion)","journal":"Acta crystallographica. Section F, Structural biology and crystallization communications","confidence":"Medium","confidence_rationale":"Tier 1 — crystal structure reported but no functional validation in this paper alone","pmids":["20693663"],"is_preprint":false},{"year":2007,"finding":"Rat SGF29 directly interacts with rADA3 and co-immunoprecipitates with rGCN5 and rSPT3, establishing it as a component of TFTC/STAGA complexes; it is recruited to c-Myc target gene promoters together with c-Myc and activates their expression.","method":"Co-immunoprecipitation, chromatin immunoprecipitation, gene expression analysis, anchorage-independent growth and tumorigenicity assays","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 — reciprocal Co-IP with multiple subunits, ChIP showing recruitment, functional knockdown phenotype","pmids":["17334388"],"is_preprint":false},{"year":2013,"finding":"Human SGF29 is required for ER stress-induced histone H3K14 acetylation at GRP78 and CHOP promoters; additionally, SGF29 is required for maintenance of H3K4me3 at these loci, and its loss reduces ASH2L (a SET1/MLL complex core component) association, revealing a dual role in coordinating both histone acetylation and H3K4 trimethylation.","method":"SGF29 knockdown, ChIP for H3K14ac and H3K4me3, co-activator binding assays, transcription analysis","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 — clean KD with defined chromatin and transcriptional phenotypes using multiple histone mark ChIPs","pmids":["23894581"],"is_preprint":false},{"year":2013,"finding":"In S. cerevisiae, the N-terminal region (aa 1–12) and the Tudor-domain-containing C-terminal region (aa 110–255) of Sgf29 each independently function as heterochromatin boundary elements; this boundary function is independent of Gcn5, distinct from the SAGA HAT module activity.","method":"Domain deletion analysis, in vivo boundary formation assay, genetic epistasis with Gcn5","journal":"Journal of biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 — domain mapping with genetic epistasis showing Gcn5-independence","pmids":["24307402"],"is_preprint":false},{"year":2023,"finding":"SGF29 forms liquid-like nuclear condensates during cellular senescence; Arg207 within the intrinsically disordered region is the key residue for phase separation, and both condensate formation and H3K4me3 binding of SGF29 are required to recruit transcription factors/co-activators to target loci (e.g., CDKN1A) and drive senescence gene expression.","method":"Live-cell imaging of condensates, mutagenesis of Arg207, epigenomic and transcriptomic analysis, ChIP","journal":"Cell discovery","confidence":"Medium","confidence_rationale":"Tier 2 — mutagenesis coupled with epigenomic analysis and live imaging, but single laboratory study","pmids":["37935676"],"is_preprint":false},{"year":2024,"finding":"SGF29 Tudor domain-dependent chromatin reading sustains transcription of AML oncogenes including MEIS1; CRISPR deletion of SGF29 impairs leukemogenesis across multiple AML subtype models, identifying SGF29 as a non-oncogenic dependency.","method":"CRISPR-Cas9 domain-focused screen, CRISPR droplet sequencing, SGF29 deletion in AML models","journal":"Blood","confidence":"Medium","confidence_rationale":"Tier 2 — CRISPR screen plus validation KO with defined transcriptional and leukemogenic phenotypes","pmids":["38048593"],"is_preprint":false},{"year":2026,"finding":"In mouse ESCs, SGF29 interacts with Oct4 and Nanog (but not Sox2) to co-regulate pluripotency genes; SGF29 knockout reduces H3K9ac and chromatin accessibility at pluripotency gene promoters/enhancers, decreases Oct4 binding to Nanog and Klf4 loci, and impairs blastocyst development.","method":"Co-immunoprecipitation (SGF29–Oct4/Nanog), SGF29 KO/KD, ATAC-seq, ChIP for H3K9ac, Oct4 ChIP","journal":"Science China. Life sciences","confidence":"Medium","confidence_rationale":"Tier 2 — Co-IP plus KO with multiple orthogonal epigenomic readouts, but single lab and recent study","pmids":["41843375"],"is_preprint":false},{"year":2024,"finding":"SGF29 (chromatin reader) promotes Alternative Lengthening of Telomeres (ALT) activity, identified through a high-throughput imaging-based genetic screen (TAILS) of >1000 genes.","method":"High-throughput RNAi/CRISPR screen with FISH-based ALT readout (TAILS screen)","journal":"bioRxiv","confidence":"Low","confidence_rationale":"Tier 3 — screen identification without mechanistic follow-up in this preprint","pmids":["bio_10.1101_2024.11.15.623791"],"is_preprint":true}],"current_model":"SGF29 is a subunit of the SAGA (and related) transcriptional coactivator complexes whose tandem Tudor domains directly bind H3K4me2/3, recruiting the SAGA HAT module to target gene promoters to promote histone H3 acetylation (H3K14ac); it also maintains H3K4me3 levels by facilitating SET1/MLL complex association, forms phase-separated nuclear condensates via Arg207 during senescence to drive senescence gene expression, and interacts with Oct4/Nanog to regulate pluripotency—with its Tudor domain serving as a key dependency in contexts such as AML leukemogenesis."},"narrative":{"teleology":[{"year":2007,"claim":"Establishing SGF29 as a bona fide SAGA-family complex subunit answered whether this uncharacterized protein was a core component of transcriptional coactivator machinery and directly linked it to c-Myc target gene activation.","evidence":"Reciprocal co-immunoprecipitation with ADA3, GCN5, and SPT3 plus ChIP at c-Myc targets in rat cells","pmids":["17334388"],"confidence":"Medium","gaps":["No structural basis for SGF29 integration into the complex","Mechanism by which SGF29 contributes to target gene selectivity undefined","Only rat system examined"]},{"year":2011,"claim":"Structural determination of the tandem Tudor domains revealed how SGF29 reads H3K4me2/3 through a face-to-face dual-pocket architecture, establishing the molecular mechanism by which SAGA is recruited to active chromatin.","evidence":"Crystal structures of yeast and human SGF29 Tudor domains bound to methylated histone peptides, validated by in vivo ChIP showing H3 acetylation dependence on Tudor–H3K4me binding","pmids":["21685874"],"confidence":"High","gaps":["Full-length SGF29 structure in complex with SAGA not determined","Relative contributions of H3K4me2 versus H3K4me3 recognition in vivo not resolved"]},{"year":2013,"claim":"Discovery that SGF29 loss reduces both H3K14ac and H3K4me3 at stress-responsive promoters and diminishes ASH2L occupancy revealed an unexpected dual role: SGF29 coordinates SAGA-mediated acetylation with SET1/MLL-mediated methylation maintenance.","evidence":"SGF29 knockdown with ChIP for H3K14ac, H3K4me3, and ASH2L at GRP78/CHOP promoters during ER stress","pmids":["23894581"],"confidence":"Medium","gaps":["Direct physical interaction between SGF29 and SET1/MLL complex subunits not demonstrated","Whether the dual role is gene-specific or genome-wide is unknown"]},{"year":2013,"claim":"Demonstration that SGF29's Tudor domain and N-terminal region independently serve as heterochromatin boundary elements—independently of Gcn5—revealed a SAGA-HAT-independent chromatin function for SGF29.","evidence":"Domain deletion analysis and genetic epistasis with Gcn5 deletion in S. cerevisiae boundary assays","pmids":["24307402"],"confidence":"Medium","gaps":["Molecular mechanism of boundary formation not identified","Whether boundary function is conserved in mammals is untested","Whether H3K4me reading is required for boundary activity is unclear"]},{"year":2023,"claim":"Finding that SGF29 forms liquid-like nuclear condensates during senescence through Arg207-dependent phase separation, and that both condensate formation and H3K4me3 binding are required for senescence gene activation, established a biomolecular condensate mechanism for SGF29-mediated transcriptional control.","evidence":"Live-cell imaging, Arg207 mutagenesis, epigenomic and transcriptomic profiling, and ChIP in senescent cells","pmids":["37935676"],"confidence":"Medium","gaps":["Single-laboratory finding not yet independently replicated","Identity of co-condensing factors not fully defined","Whether phase separation contributes to SGF29 function outside senescence is unknown"]},{"year":2024,"claim":"A CRISPR domain-focused screen identified SGF29's Tudor domain as a non-oncogenic dependency in AML, showing that Tudor-dependent chromatin reading sustains MEIS1 and other oncogene transcription across multiple AML subtypes.","evidence":"CRISPR-Cas9 screen and SGF29 deletion in multiple AML subtype models with transcriptional and leukemogenic phenotyping","pmids":["38048593"],"confidence":"Medium","gaps":["Therapeutic targeting strategy for the Tudor domain not developed","Whether SAGA-independent SGF29 functions contribute to AML dependency is untested"]},{"year":2026,"claim":"Demonstrating that SGF29 interacts with Oct4 and Nanog to maintain H3K9ac and chromatin accessibility at pluripotency loci established SGF29 as an epigenetic regulator of embryonic stem cell identity and early development.","evidence":"Co-IP of SGF29 with Oct4/Nanog, SGF29 KO/KD in mouse ESCs with ATAC-seq and H3K9ac/Oct4 ChIP, blastocyst development assay","pmids":["41843375"],"confidence":"Medium","gaps":["Single-laboratory study not yet independently confirmed","Whether SGF29–Oct4/Nanog interaction is direct or mediated through SAGA is unresolved","Specificity of SGF29 versus other Tudor domain proteins in pluripotency is not addressed"]},{"year":null,"claim":"Key unresolved questions include the full structural context of SGF29 within the assembled SAGA complex, whether its phase-separation capacity operates in non-senescence contexts, the mechanism underlying its heterochromatin boundary function, and whether the Tudor domain can be therapeutically targeted in AML.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No full-length cryo-EM structure of SGF29 within SAGA","Direct versus SAGA-mediated nature of Oct4/Nanog interaction unresolved","Boundary element mechanism molecularly undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0042393","term_label":"histone binding","supporting_discovery_ids":[0,1,5,6]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0,2,5,7]},{"term_id":"GO:0005694","term_label":"chromosome","supporting_discovery_ids":[0,3,4]}],"pathway":[{"term_id":"R-HSA-4839726","term_label":"Chromatin organization","supporting_discovery_ids":[0,3,4,5]},{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[2,3,5,6,7]}],"complexes":["SAGA","STAGA/TFTC"],"partners":["ADA3","GCN5","SPT3","ASH2L","OCT4","NANOG"],"other_free_text":[]},"mechanistic_narrative":"SGF29 is a chromatin reader subunit of SAGA-family transcriptional coactivator complexes that couples recognition of active histone marks to transcriptional activation across diverse biological contexts. Its tandem Tudor domains bind H3K4me2/3 through a bipartite pocket architecture, recruiting the SAGA complex to target promoters to stimulate histone H3 acetylation (H3K14ac, H3K9ac) [PMID:21685874, PMID:23894581, PMID:41843375]. Beyond HAT-module recruitment, SGF29 maintains H3K4me3 levels by facilitating SET1/MLL complex association, functions as a heterochromatin boundary element through both its N-terminal and Tudor-domain regions independently of Gcn5, and forms phase-separated nuclear condensates via its intrinsically disordered region (Arg207) during senescence to concentrate transcriptional machinery at target loci such as CDKN1A [PMID:23894581, PMID:24307402, PMID:37935676]. SGF29 Tudor domain–dependent chromatin reading sustains oncogene expression in AML and is required for pluripotency gene regulation through interaction with Oct4 and Nanog in embryonic stem cells [PMID:38048593, PMID:41843375]."},"prefetch_data":{"uniprot":{"accession":"Q96ES7","full_name":"SAGA-associated factor 29","aliases":["Coiled-coil domain-containing protein 101","SAGA complex-associated factor 29"],"length_aa":293,"mass_kda":33.2,"function":"Chromatin reader component of some histone acetyltransferase (HAT) SAGA-type complexes like the TFTC-HAT, ATAC or STAGA complexes (PubMed:19103755, PubMed:20850016, PubMed:21685874, PubMed:26421618, PubMed:26578293). SGF29 specifically recognizes and binds methylated 'Lys-4' of histone H3 (H3K4me), with a preference for trimethylated form (H3K4me3) (PubMed:20850016, PubMed:21685874, PubMed:26421618, PubMed:26578293). In the SAGA-type complexes, SGF29 is required to recruit complexes to H3K4me (PubMed:20850016). Involved in the response to endoplasmic reticulum (ER) stress by recruiting the SAGA complex to H3K4me, thereby promoting histone H3 acetylation and cell survival (PubMed:23894581). Also binds non-histone proteins that are methylated on Lys residues: specifically recognizes and binds CGAS monomethylated on 'Lys-506' (By similarity)","subcellular_location":"Nucleus","url":"https://www.uniprot.org/uniprotkb/Q96ES7/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/SGF29","classification":"Not Classified","n_dependent_lines":737,"n_total_lines":1208,"dependency_fraction":0.6100993377483444},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"TAF12","stoichiometry":10.0},{"gene":"TRRAP","stoichiometry":10.0},{"gene":"USP22","stoichiometry":4.0},{"gene":"ACTB","stoichiometry":0.2},{"gene":"ENY2","stoichiometry":0.2},{"gene":"SF3B3","stoichiometry":0.2},{"gene":"SF3B5","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/SGF29","total_profiled":1310},"omim":[],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoli","reliability":"Supported"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/SGF29"},"hgnc":{"alias_symbol":["FLJ32446","TDRD29"],"prev_symbol":["CCDC101"]},"alphafold":{"accession":"Q96ES7","domains":[{"cath_id":"2.30.30.140","chopping":"223-285","consensus_level":"medium","plddt":97.2895,"start":223,"end":285},{"cath_id":"1.10.287","chopping":"1-111","consensus_level":"medium","plddt":89.422,"start":1,"end":111}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96ES7","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q96ES7-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q96ES7-F1-predicted_aligned_error_v6.png","plddt_mean":91.75},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=SGF29","jax_strain_url":"https://www.jax.org/strain/search?query=SGF29"},"sequence":{"accession":"Q96ES7","fasta_url":"https://rest.uniprot.org/uniprotkb/Q96ES7.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q96ES7/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96ES7"}},"corpus_meta":[{"pmid":"21685874","id":"PMC_21685874","title":"Sgf29 binds histone H3K4me2/3 and is required for SAGA complex recruitment and histone H3 acetylation.","date":"2011","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/21685874","citation_count":208,"is_preprint":false},{"pmid":"23894581","id":"PMC_23894581","title":"A dual role for SAGA-associated factor 29 (SGF29) in ER stress survival by coordination of both histone H3 acetylation and histone H3 lysine-4 trimethylation.","date":"2013","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/23894581","citation_count":38,"is_preprint":false},{"pmid":"32890768","id":"PMC_32890768","title":"The Ada2/Ada3/Gcn5/Sgf29 histone acetyltransferase module.","date":"2020","source":"Biochimica et biophysica acta. Gene regulatory mechanisms","url":"https://pubmed.ncbi.nlm.nih.gov/32890768","citation_count":35,"is_preprint":false},{"pmid":"37935676","id":"PMC_37935676","title":"SGF29 nuclear condensates reinforce cellular aging.","date":"2023","source":"Cell discovery","url":"https://pubmed.ncbi.nlm.nih.gov/37935676","citation_count":29,"is_preprint":false},{"pmid":"17334388","id":"PMC_17334388","title":"Deregulated expression of a novel component of TFTC/STAGA histone acetyltransferase complexes, rat SGF29, in hepatocellular carcinoma: possible implication for the oncogenic potential of c-Myc.","date":"2007","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/17334388","citation_count":29,"is_preprint":false},{"pmid":"38048593","id":"PMC_38048593","title":"Transcriptional control of leukemogenesis by the chromatin reader SGF29.","date":"2024","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/38048593","citation_count":13,"is_preprint":false},{"pmid":"24307402","id":"PMC_24307402","title":"The N-terminus and Tudor domains of Sgf29 are important for its heterochromatin boundary formation function.","date":"2013","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/24307402","citation_count":12,"is_preprint":false},{"pmid":"26322172","id":"PMC_26322172","title":"SGF29 and Sry pathway in hepatocarcinogenesis.","date":"2015","source":"World journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26322172","citation_count":8,"is_preprint":false},{"pmid":"20693663","id":"PMC_20693663","title":"Cloning, purification, crystallization and preliminary crystallographic analysis of the tandem tudor domain of Sgf29 from Saccharomyces cerevisiae.","date":"2010","source":"Acta crystallographica. Section F, Structural biology and crystallization communications","url":"https://pubmed.ncbi.nlm.nih.gov/20693663","citation_count":5,"is_preprint":false},{"pmid":"41843375","id":"PMC_41843375","title":"Sgf29 regulates pluripotency by maintaining chromatin accessibility and promoting the expression of core transcription factors.","date":"2026","source":"Science China. Life sciences","url":"https://pubmed.ncbi.nlm.nih.gov/41843375","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2024.11.15.623791","title":"Identification of Novel Modulators of the ALT Pathway Through a Native FISH-Based Optical Screen","date":"2024-11-15","source":"bioRxiv","url":"https://doi.org/10.1101/2024.11.15.623791","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":6051,"output_tokens":2087,"usd":0.024729},"stage2":{"model":"claude-opus-4-6","input_tokens":5390,"output_tokens":2208,"usd":0.123225},"total_usd":0.147954,"stage1_batch_id":"msgbatch_011rkcQdVV1RaFq9XhcG6df6","stage2_batch_id":"msgbatch_01RzgrJafdF4EWHhj5mNi6dh","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2011,\n      \"finding\": \"Crystal structures of the tandem Tudor domains of S. cerevisiae and human SGF29 reveal that these domains selectively bind H3K4me2/3 marks; the tandem Tudor domains pack face-to-face with one pocket accommodating H3A1 and the other accommodating K4me2/3, and this interaction recruits the SAGA complex to target sites to mediate histone H3 acetylation in vivo.\",\n      \"method\": \"Crystal structure determination, histone peptide binding assays, in vitro functional assays, and in vivo chromatin recruitment/acetylation assays\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — crystal structures with functional validation by in vitro and in vivo assays, high citation count indicating replication\",\n      \"pmids\": [\"21685874\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"The tandem Tudor domain at the C-terminus of S. cerevisiae Sgf29 was crystallized and diffracted to 1.92 Å resolution, establishing the structural basis for subsequent functional studies.\",\n      \"method\": \"X-ray crystallography (hanging-drop vapour-diffusion)\",\n      \"journal\": \"Acta crystallographica. Section F, Structural biology and crystallization communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 — crystal structure reported but no functional validation in this paper alone\",\n      \"pmids\": [\"20693663\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Rat SGF29 directly interacts with rADA3 and co-immunoprecipitates with rGCN5 and rSPT3, establishing it as a component of TFTC/STAGA complexes; it is recruited to c-Myc target gene promoters together with c-Myc and activates their expression.\",\n      \"method\": \"Co-immunoprecipitation, chromatin immunoprecipitation, gene expression analysis, anchorage-independent growth and tumorigenicity assays\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal Co-IP with multiple subunits, ChIP showing recruitment, functional knockdown phenotype\",\n      \"pmids\": [\"17334388\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Human SGF29 is required for ER stress-induced histone H3K14 acetylation at GRP78 and CHOP promoters; additionally, SGF29 is required for maintenance of H3K4me3 at these loci, and its loss reduces ASH2L (a SET1/MLL complex core component) association, revealing a dual role in coordinating both histone acetylation and H3K4 trimethylation.\",\n      \"method\": \"SGF29 knockdown, ChIP for H3K14ac and H3K4me3, co-activator binding assays, transcription analysis\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KD with defined chromatin and transcriptional phenotypes using multiple histone mark ChIPs\",\n      \"pmids\": [\"23894581\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"In S. cerevisiae, the N-terminal region (aa 1–12) and the Tudor-domain-containing C-terminal region (aa 110–255) of Sgf29 each independently function as heterochromatin boundary elements; this boundary function is independent of Gcn5, distinct from the SAGA HAT module activity.\",\n      \"method\": \"Domain deletion analysis, in vivo boundary formation assay, genetic epistasis with Gcn5\",\n      \"journal\": \"Journal of biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — domain mapping with genetic epistasis showing Gcn5-independence\",\n      \"pmids\": [\"24307402\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"SGF29 forms liquid-like nuclear condensates during cellular senescence; Arg207 within the intrinsically disordered region is the key residue for phase separation, and both condensate formation and H3K4me3 binding of SGF29 are required to recruit transcription factors/co-activators to target loci (e.g., CDKN1A) and drive senescence gene expression.\",\n      \"method\": \"Live-cell imaging of condensates, mutagenesis of Arg207, epigenomic and transcriptomic analysis, ChIP\",\n      \"journal\": \"Cell discovery\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — mutagenesis coupled with epigenomic analysis and live imaging, but single laboratory study\",\n      \"pmids\": [\"37935676\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"SGF29 Tudor domain-dependent chromatin reading sustains transcription of AML oncogenes including MEIS1; CRISPR deletion of SGF29 impairs leukemogenesis across multiple AML subtype models, identifying SGF29 as a non-oncogenic dependency.\",\n      \"method\": \"CRISPR-Cas9 domain-focused screen, CRISPR droplet sequencing, SGF29 deletion in AML models\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — CRISPR screen plus validation KO with defined transcriptional and leukemogenic phenotypes\",\n      \"pmids\": [\"38048593\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"In mouse ESCs, SGF29 interacts with Oct4 and Nanog (but not Sox2) to co-regulate pluripotency genes; SGF29 knockout reduces H3K9ac and chromatin accessibility at pluripotency gene promoters/enhancers, decreases Oct4 binding to Nanog and Klf4 loci, and impairs blastocyst development.\",\n      \"method\": \"Co-immunoprecipitation (SGF29–Oct4/Nanog), SGF29 KO/KD, ATAC-seq, ChIP for H3K9ac, Oct4 ChIP\",\n      \"journal\": \"Science China. Life sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — Co-IP plus KO with multiple orthogonal epigenomic readouts, but single lab and recent study\",\n      \"pmids\": [\"41843375\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"SGF29 (chromatin reader) promotes Alternative Lengthening of Telomeres (ALT) activity, identified through a high-throughput imaging-based genetic screen (TAILS) of >1000 genes.\",\n      \"method\": \"High-throughput RNAi/CRISPR screen with FISH-based ALT readout (TAILS screen)\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — screen identification without mechanistic follow-up in this preprint\",\n      \"pmids\": [\"bio_10.1101_2024.11.15.623791\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"SGF29 is a subunit of the SAGA (and related) transcriptional coactivator complexes whose tandem Tudor domains directly bind H3K4me2/3, recruiting the SAGA HAT module to target gene promoters to promote histone H3 acetylation (H3K14ac); it also maintains H3K4me3 levels by facilitating SET1/MLL complex association, forms phase-separated nuclear condensates via Arg207 during senescence to drive senescence gene expression, and interacts with Oct4/Nanog to regulate pluripotency—with its Tudor domain serving as a key dependency in contexts such as AML leukemogenesis.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"SGF29 is a chromatin reader subunit of SAGA-family transcriptional coactivator complexes that couples recognition of active histone marks to transcriptional activation across diverse biological contexts. Its tandem Tudor domains bind H3K4me2/3 through a bipartite pocket architecture, recruiting the SAGA complex to target promoters to stimulate histone H3 acetylation (H3K14ac, H3K9ac) [PMID:21685874, PMID:23894581, PMID:41843375]. Beyond HAT-module recruitment, SGF29 maintains H3K4me3 levels by facilitating SET1/MLL complex association, functions as a heterochromatin boundary element through both its N-terminal and Tudor-domain regions independently of Gcn5, and forms phase-separated nuclear condensates via its intrinsically disordered region (Arg207) during senescence to concentrate transcriptional machinery at target loci such as CDKN1A [PMID:23894581, PMID:24307402, PMID:37935676]. SGF29 Tudor domain–dependent chromatin reading sustains oncogene expression in AML and is required for pluripotency gene regulation through interaction with Oct4 and Nanog in embryonic stem cells [PMID:38048593, PMID:41843375].\",\n  \"teleology\": [\n    {\n      \"year\": 2007,\n      \"claim\": \"Establishing SGF29 as a bona fide SAGA-family complex subunit answered whether this uncharacterized protein was a core component of transcriptional coactivator machinery and directly linked it to c-Myc target gene activation.\",\n      \"evidence\": \"Reciprocal co-immunoprecipitation with ADA3, GCN5, and SPT3 plus ChIP at c-Myc targets in rat cells\",\n      \"pmids\": [\"17334388\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No structural basis for SGF29 integration into the complex\",\n        \"Mechanism by which SGF29 contributes to target gene selectivity undefined\",\n        \"Only rat system examined\"\n      ]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Structural determination of the tandem Tudor domains revealed how SGF29 reads H3K4me2/3 through a face-to-face dual-pocket architecture, establishing the molecular mechanism by which SAGA is recruited to active chromatin.\",\n      \"evidence\": \"Crystal structures of yeast and human SGF29 Tudor domains bound to methylated histone peptides, validated by in vivo ChIP showing H3 acetylation dependence on Tudor–H3K4me binding\",\n      \"pmids\": [\"21685874\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Full-length SGF29 structure in complex with SAGA not determined\",\n        \"Relative contributions of H3K4me2 versus H3K4me3 recognition in vivo not resolved\"\n      ]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Discovery that SGF29 loss reduces both H3K14ac and H3K4me3 at stress-responsive promoters and diminishes ASH2L occupancy revealed an unexpected dual role: SGF29 coordinates SAGA-mediated acetylation with SET1/MLL-mediated methylation maintenance.\",\n      \"evidence\": \"SGF29 knockdown with ChIP for H3K14ac, H3K4me3, and ASH2L at GRP78/CHOP promoters during ER stress\",\n      \"pmids\": [\"23894581\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct physical interaction between SGF29 and SET1/MLL complex subunits not demonstrated\",\n        \"Whether the dual role is gene-specific or genome-wide is unknown\"\n      ]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Demonstration that SGF29's Tudor domain and N-terminal region independently serve as heterochromatin boundary elements—independently of Gcn5—revealed a SAGA-HAT-independent chromatin function for SGF29.\",\n      \"evidence\": \"Domain deletion analysis and genetic epistasis with Gcn5 deletion in S. cerevisiae boundary assays\",\n      \"pmids\": [\"24307402\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular mechanism of boundary formation not identified\",\n        \"Whether boundary function is conserved in mammals is untested\",\n        \"Whether H3K4me reading is required for boundary activity is unclear\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Finding that SGF29 forms liquid-like nuclear condensates during senescence through Arg207-dependent phase separation, and that both condensate formation and H3K4me3 binding are required for senescence gene activation, established a biomolecular condensate mechanism for SGF29-mediated transcriptional control.\",\n      \"evidence\": \"Live-cell imaging, Arg207 mutagenesis, epigenomic and transcriptomic profiling, and ChIP in senescent cells\",\n      \"pmids\": [\"37935676\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Single-laboratory finding not yet independently replicated\",\n        \"Identity of co-condensing factors not fully defined\",\n        \"Whether phase separation contributes to SGF29 function outside senescence is unknown\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"A CRISPR domain-focused screen identified SGF29's Tudor domain as a non-oncogenic dependency in AML, showing that Tudor-dependent chromatin reading sustains MEIS1 and other oncogene transcription across multiple AML subtypes.\",\n      \"evidence\": \"CRISPR-Cas9 screen and SGF29 deletion in multiple AML subtype models with transcriptional and leukemogenic phenotyping\",\n      \"pmids\": [\"38048593\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Therapeutic targeting strategy for the Tudor domain not developed\",\n        \"Whether SAGA-independent SGF29 functions contribute to AML dependency is untested\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Demonstrating that SGF29 interacts with Oct4 and Nanog to maintain H3K9ac and chromatin accessibility at pluripotency loci established SGF29 as an epigenetic regulator of embryonic stem cell identity and early development.\",\n      \"evidence\": \"Co-IP of SGF29 with Oct4/Nanog, SGF29 KO/KD in mouse ESCs with ATAC-seq and H3K9ac/Oct4 ChIP, blastocyst development assay\",\n      \"pmids\": [\"41843375\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Single-laboratory study not yet independently confirmed\",\n        \"Whether SGF29–Oct4/Nanog interaction is direct or mediated through SAGA is unresolved\",\n        \"Specificity of SGF29 versus other Tudor domain proteins in pluripotency is not addressed\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Key unresolved questions include the full structural context of SGF29 within the assembled SAGA complex, whether its phase-separation capacity operates in non-senescence contexts, the mechanism underlying its heterochromatin boundary function, and whether the Tudor domain can be therapeutically targeted in AML.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No full-length cryo-EM structure of SGF29 within SAGA\",\n        \"Direct versus SAGA-mediated nature of Oct4/Nanog interaction unresolved\",\n        \"Boundary element mechanism molecularly undefined\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0042393\", \"supporting_discovery_ids\": [0, 1, 5, 6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0, 2, 5, 7]},\n      {\"term_id\": \"GO:0005694\", \"supporting_discovery_ids\": [0, 3, 4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-4839726\", \"supporting_discovery_ids\": [0, 3, 4, 5]},\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [2, 3, 5, 6, 7]}\n    ],\n    \"complexes\": [\n      \"SAGA\",\n      \"STAGA/TFTC\"\n    ],\n    \"partners\": [\n      \"ADA3\",\n      \"GCN5\",\n      \"SPT3\",\n      \"ASH2L\",\n      \"Oct4\",\n      \"Nanog\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}