{"gene":"SYF2","run_date":"2026-06-10T10:51:54","timeline":{"discoveries":[{"year":2020,"finding":"SYF2 is associated with ECT2 pre-mRNA and controls alternative splicing programs in breast cancer cells; SYF2 depletion by RNAi reversed doxorubicin resistance and altered S-phase accumulation in resistant cells. Both SYF2 and ZRANB2 AS programs converged on inclusion of ECT2 exon 5 (ECT2-Ex5+).","method":"RNAi screen, RNA-seq, RIP (RNA immunoprecipitation showing SYF2 association with ECT2 pre-mRNA), cell-cycle analysis","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal RIP confirming SYF2–ECT2 pre-mRNA association, RNAi phenotypic rescue, RNA-seq for splicing program; single lab","pmids":["31943118"],"is_preprint":false},{"year":2023,"finding":"Suppression of SYF2, a spliceosome-associated factor, alleviates TDP-43 aggregation and mislocalization, improves TDP-43 activity, and rescues neuronal survival in C9ORF72 and sporadic ALS patient-derived neurons; Syf2 suppression also ameliorates neurodegeneration, neuromuscular junction loss, and motor dysfunction in TDP-43 mice.","method":"RNAi/genetic suppression in patient-derived neurons, mouse in vivo loss-of-function (TDP-43 mouse model), bioinformatic chemical/genetic perturbational analysis","journal":"Cell stem cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo mouse model plus patient-derived neuron system, multiple ALS genotypes tested; single lab but orthogonal models","pmids":["36736291"],"is_preprint":false},{"year":2012,"finding":"Mouse p29/Syf2/Ntc31 is required for embryonic viability; homozygous knockout causes lethality by E6.5 with decreased Chk1 and α-tubulin mRNA levels (via impaired post-transcriptional regulation), and an aberrant G2/M DNA damage checkpoint response to aphidicolin and UV. Knockdown of the zebrafish ortholog (zfp29) similarly causes embryonic death with reduced acetylated α-tubulin.","method":"Gene-trap knockout mouse, siRNA knockdown in zebrafish (morpholino), RT-qPCR for Chk1/α-tubulin mRNAs, checkpoint assay with aphidicolin/UV, rescue by transgenic mp29 re-expression","journal":"PloS one","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo knockout with transgenic rescue, two animal models (mouse and zebrafish), multiple orthogonal readouts","pmids":["22448250"],"is_preprint":false},{"year":2014,"finding":"SYF2 knockdown in NSCLC A549 cells blocks S-phase entry, inhibits proliferation, and upregulates p21 expression, indicating SYF2 is required for G1/S cell-cycle progression in cancer cells.","method":"siRNA knockdown, flow cytometry cell-cycle analysis, Western blot for p21","journal":"Pathology, research and practice","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single siRNA approach, no rescue experiment","pmids":["25433998"],"is_preprint":false},{"year":2014,"finding":"SYF2 knockdown in glioma U87 cells arrests growth at G1 phase and reduces PCNA and cyclin D1 expression, supporting a role for SYF2 in G1/S transition through regulation of cyclin D1 levels.","method":"siRNA knockdown, flow cytometry, Western blot for PCNA and cyclin D1","journal":"Medical oncology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single siRNA approach, no rescue experiment","pmids":["24985881"],"is_preprint":false},{"year":2013,"finding":"SYF2 upregulation in astrocytes (C6 cells) after LPS challenge is required for astrocyte activation; SYF2 silencing in C6 cells and PC12 neuronal cells reduced LPS-induced astrocyte activation and neuronal apoptosis, respectively.","method":"siRNA knockdown in C6 and PC12 cells, conditioned media apoptosis assay, LPS neuroinflammation rat model","journal":"Journal of neuroscience research","confidence":"Low","confidence_rationale":"Tier 3 / Weak — siRNA knockdown in cell lines, no mechanistic pathway placement beyond cellular phenotype","pmids":["24301298"],"is_preprint":false},{"year":2014,"finding":"SYF2 is required for Schwann cell migration after sciatic nerve injury; SYF2-specific siRNA transfection in Schwann cells produced shorter, disorganized microtubule structures and decreased cell migration, suggesting SYF2 modulates microtubule dynamics in Schwann cells.","method":"siRNA knockdown in primary Schwann cells, immunofluorescence of microtubule structure, migration assay, rat sciatic nerve crush in vivo model","journal":"Cellular and molecular neurobiology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, siRNA phenotype in cell culture with in vivo correlative expression; no mechanistic rescue","pmids":["24962097"],"is_preprint":false},{"year":2019,"finding":"MiR-376c-3p directly targets the SYF2 3'-UTR to reduce SYF2 expression, and SYF2 overexpression abrogates the inhibitory effects of miR-376c-3p on gastric cancer cell proliferation and migration, placing SYF2 downstream of miR-376c-3p in this pathway.","method":"Luciferase reporter assay (miRNA–3'UTR targeting), overexpression/knockdown, proliferation and migration assays","journal":"Technology in cancer research & treatment","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, luciferase reporter for targeting validation, no deep mechanistic characterization of SYF2 function","pmids":["31522605"],"is_preprint":false},{"year":2020,"finding":"MiR-621 directly interacts with the SYF2 3'-UTR and post-transcriptionally represses SYF2 expression in gastric cancer cells; SYF2 overexpression reversed the anti-proliferative effects of miR-621, confirming SYF2 is a functional target.","method":"Luciferase reporter assay (direct 3'-UTR interaction), gain/loss-of-function experiments, xenograft model","journal":"Archives of biochemistry and biophysics","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, luciferase 3'-UTR reporter, rescue experiment but no deep mechanistic characterization of SYF2","pmids":["32417187"],"is_preprint":false},{"year":2024,"finding":"Yeast Syf2, a subunit of the Prp19C/NTC complex, is required for full Prp19C occupancy at transcribed genes and for the interaction between Prp19C and TREX, thereby coupling transcription elongation to nuclear mRNA export. Genetic interaction between Δsyf2 and Δcwc15 confirmed partially overlapping functions in Prp19C–TREX interaction.","method":"Chromatin immunoprecipitation (ChIP) for Prp19C and TREX occupancy, co-immunoprecipitation (Co-IP) for Prp19C–TREX interaction, genetic interaction (double deletion analysis), transcription elongation assays in yeast","journal":"RNA (New York, N.Y.)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP, Co-IP, and genetic epistasis in yeast; multiple orthogonal methods; single lab","pmids":["38627018"],"is_preprint":false}],"current_model":"SYF2 (p29/NTC31/fSAP29) is a conserved spliceosome-associated subunit of the Prp19C/NTC complex that regulates pre-mRNA splicing and alternative splicing programs (including ECT2 exon inclusion), supports full Prp19C occupancy at transcribed genes to couple transcription elongation with nuclear mRNA export via TREX, is required for DNA damage checkpoint responses (Chk1/α-tubulin post-transcriptional regulation), and promotes G1/S cell-cycle progression; its suppression alleviates TDP-43 pathology in ALS models, and it is post-transcriptionally regulated by miR-376c-3p and miR-621 through direct 3'-UTR targeting."},"narrative":{"mechanistic_narrative":"SYF2 (p29/NTC31) is a conserved subunit of the Prp19C/NTC spliceosome-associated complex that links pre-mRNA splicing and alternative splicing to downstream gene-expression and cell-cycle programs [PMID:31943118, PMID:38627018]. In yeast, Syf2 is required for full Prp19C occupancy at transcribed genes and for the Prp19C–TREX interaction, thereby coupling transcription elongation to nuclear mRNA export, with overlapping function shared with Cwc15 [PMID:38627018]. In mammalian cells SYF2 directs alternative splicing programs, associating with ECT2 pre-mRNA and driving ECT2 exon 5 inclusion, a program convergent with ZRANB2 [PMID:31943118]. SYF2 is essential for embryonic viability, with loss causing early lethality, reduced Chk1 and α-tubulin mRNA levels, and an aberrant DNA damage checkpoint response [PMID:22448250]. Across cancer and developmental contexts SYF2 promotes G1/S cell-cycle progression [PMID:31943118, PMID:22448250], and its suppression alleviates TDP-43 aggregation, mislocalization, and neurodegeneration in ALS models [PMID:36736291]. SYF2 is post-transcriptionally repressed through direct 3'-UTR targeting by miR-376c-3p and miR-621 [PMID:31522605, PMID:32417187].","teleology":[{"year":2012,"claim":"Established that SYF2 is essential in vivo and functionally couples post-transcriptional control of Chk1/α-tubulin to the DNA damage checkpoint, moving it beyond a presumed splicing factor to a developmentally required regulator.","evidence":"Gene-trap knockout mouse with transgenic rescue, zebrafish morpholino knockdown, RT-qPCR and aphidicolin/UV checkpoint assays","pmids":["22448250"],"confidence":"High","gaps":["Direct molecular mechanism linking SYF2 to Chk1/α-tubulin mRNA stability not resolved","Whether the checkpoint defect is a direct splicing consequence or indirect is unclear"]},{"year":2013,"claim":"Linked SYF2 expression to glial/neuronal injury responses, raising a role in neuroinflammation beyond constitutive cell-cycle function.","evidence":"siRNA knockdown in C6 astrocyte and PC12 neuronal cell lines, conditioned-media apoptosis assay, LPS rat model","pmids":["24301298"],"confidence":"Low","gaps":["No mechanistic pathway placement beyond cellular phenotype","No rescue experiment"]},{"year":2014,"claim":"Multiple cancer/neural systems converged on SYF2 as a driver of G1/S progression, implicating cyclin D1 and p21 as affected nodes and microtubule dynamics in Schwann cell migration.","evidence":"siRNA knockdown with flow cytometry and Western blot (p21, PCNA, cyclin D1) in A549 and U87 cells; siRNA plus microtubule imaging and migration assay in primary Schwann cells with sciatic nerve injury model","pmids":["25433998","24985881","24962097"],"confidence":"Low","gaps":["Single siRNA approaches without rescue","Whether cyclin D1/p21/microtubule effects are direct splicing targets unknown"]},{"year":2019,"claim":"Identified SYF2 as a post-transcriptionally regulated target, with miR-376c-3p directly binding its 3'-UTR to repress proliferation and migration.","evidence":"Luciferase 3'-UTR reporter assay, overexpression/knockdown, proliferation and migration assays in gastric cancer cells","pmids":["31522605"],"confidence":"Low","gaps":["No deep mechanistic characterization of SYF2 downstream function","Single lab"]},{"year":2020,"claim":"Connected SYF2's splicing activity to a defined alternative splicing program (ECT2 exon 5 inclusion) and to chemotherapy resistance, defining a mechanistic output of SYF2 in cancer cells; a second study confirmed miR-621 as an additional 3'-UTR repressor.","evidence":"RNAi screen, RNA-seq, RIP showing SYF2–ECT2 pre-mRNA association, cell-cycle analysis (idx 0); luciferase 3'-UTR reporter and xenograft rescue (idx 8)","pmids":["31943118","32417187"],"confidence":"Medium","gaps":["Direct splice-site contacts of SYF2 not mapped","How ECT2-Ex5+ inclusion mediates doxorubicin resistance not fully defined"]},{"year":2023,"claim":"Showed that lowering SYF2 is protective in disease, alleviating TDP-43 pathology and neurodegeneration across multiple ALS models, establishing SYF2 as a disease modifier.","evidence":"RNAi/genetic suppression in C9ORF72 and sporadic ALS patient-derived neurons, TDP-43 mouse loss-of-function, perturbational bioinformatics","pmids":["36736291"],"confidence":"Medium","gaps":["Mechanism connecting SYF2 splicing function to TDP-43 aggregation unresolved","Whether protection is splicing-dependent unknown"]},{"year":2024,"claim":"Mechanistically placed Syf2 within Prp19C, showing it is required for Prp19C occupancy at genes and for the Prp19C–TREX interaction, thereby coupling transcription elongation to mRNA export.","evidence":"ChIP for Prp19C/TREX occupancy, Co-IP for Prp19C–TREX interaction, Δsyf2/Δcwc15 genetic epistasis, transcription elongation assays in yeast","pmids":["38627018"],"confidence":"Medium","gaps":["Conservation of the Prp19C–TREX coupling role in mammals not demonstrated","Structural basis of Syf2's contribution to Prp19C occupancy unknown"]},{"year":null,"claim":"How SYF2's core role in Prp19C-dependent splicing and transcription–export coupling mechanistically produces its specific phenotypic outputs — checkpoint regulation, G1/S progression, and TDP-43 protection — remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No direct link between splicing activity and Chk1/α-tubulin/cyclin D1 regulation","Mammalian Prp19C–TREX coupling untested","Mechanism of TDP-43 rescue undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140098","term_label":"catalytic activity, acting on RNA","supporting_discovery_ids":[0,9]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0,9]}],"pathway":[{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[0,9]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[2]}],"complexes":["Prp19C/NTC"],"partners":["TREX","CWC15","ECT2","ZRANB2"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O95926","full_name":"Pre-mRNA-splicing factor SYF2","aliases":["CCNDBP1-interactor","p29"],"length_aa":243,"mass_kda":28.7,"function":"Involved in pre-mRNA splicing as component of the spliceosome (PubMed:11991638, PubMed:28076346, PubMed:28502770)","subcellular_location":"Nucleus","url":"https://www.uniprot.org/uniprotkb/O95926/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/SYF2","classification":"Common Essential","n_dependent_lines":1160,"n_total_lines":1208,"dependency_fraction":0.9602649006622517},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CPSF6","stoichiometry":0.2},{"gene":"SNRPA","stoichiometry":0.2},{"gene":"SNRPB","stoichiometry":0.2},{"gene":"SNRPF","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/SYF2","total_profiled":1310},"omim":[{"mim_id":"621501","title":"CWC15, SPLICEOSOME-ASSOCIATED PROTEIN; CWC15","url":"https://www.omim.org/entry/621501"},{"mim_id":"615562","title":"SPERM-ASSOCIATED ANTIGEN 5; SPAG5","url":"https://www.omim.org/entry/615562"},{"mim_id":"607090","title":"SYF2 PRE-mRNA SPLICING FACTOR; SYF2","url":"https://www.omim.org/entry/607090"}],"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/SYF2"},"hgnc":{"alias_symbol":["p29","DKFZp564O2082","NTC31","fSAP29"],"prev_symbol":["CBPIN"]},"alphafold":{"accession":"O95926","domains":[{"cath_id":"-","chopping":"211-243","consensus_level":"medium","plddt":93.4221,"start":211,"end":243}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O95926","model_url":"https://alphafold.ebi.ac.uk/files/AF-O95926-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O95926-F1-predicted_aligned_error_v6.png","plddt_mean":86.5},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=SYF2","jax_strain_url":"https://www.jax.org/strain/search?query=SYF2"},"sequence":{"accession":"O95926","fasta_url":"https://rest.uniprot.org/uniprotkb/O95926.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O95926/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O95926"}},"corpus_meta":[{"pmid":"32392397","id":"PMC_32392397","title":"Modular and Selective Arylation of Aryl Germanes (C-GeEt3 ) over C-Bpin, C-SiR3 and Halogens Enabled by Light-Activated Gold Catalysis.","date":"2020","source":"Angewandte Chemie (International ed. in English)","url":"https://pubmed.ncbi.nlm.nih.gov/32392397","citation_count":54,"is_preprint":false},{"pmid":"31943118","id":"PMC_31943118","title":"ZRANB2 and SYF2-mediated splicing programs converging on ECT2 are involved in breast cancer cell resistance to doxorubicin.","date":"2020","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/31943118","citation_count":36,"is_preprint":false},{"pmid":"36736291","id":"PMC_36736291","title":"SYF2 suppression mitigates neurodegeneration in models of diverse forms of ALS.","date":"2023","source":"Cell stem cell","url":"https://pubmed.ncbi.nlm.nih.gov/36736291","citation_count":21,"is_preprint":false},{"pmid":"22448250","id":"PMC_22448250","title":"Disruption of murine mp29/Syf2/Ntc31 gene results in embryonic lethality with aberrant checkpoint response.","date":"2012","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/22448250","citation_count":19,"is_preprint":false},{"pmid":"24301298","id":"PMC_24301298","title":"Upregulation of SYF2 is associated with neuronal apoptosis caused by reactive astrogliosis to neuroinflammation.","date":"2013","source":"Journal of neuroscience research","url":"https://pubmed.ncbi.nlm.nih.gov/24301298","citation_count":16,"is_preprint":false},{"pmid":"25433998","id":"PMC_25433998","title":"Involvement of p29/SYF2/fSAP29/NTC31 in the progression of NSCLC via modulating cell proliferation.","date":"2014","source":"Pathology, research and practice","url":"https://pubmed.ncbi.nlm.nih.gov/25433998","citation_count":9,"is_preprint":false},{"pmid":"24985881","id":"PMC_24985881","title":"Knocking down the expression of SYF2 inhibits the proliferation of glioma cells.","date":"2014","source":"Medical oncology (Northwood, London, England)","url":"https://pubmed.ncbi.nlm.nih.gov/24985881","citation_count":9,"is_preprint":false},{"pmid":"25623116","id":"PMC_25623116","title":"SYF2 is upregulated in human epithelial ovarian cancer and promotes cell proliferation.","date":"2015","source":"Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine","url":"https://pubmed.ncbi.nlm.nih.gov/25623116","citation_count":8,"is_preprint":false},{"pmid":"25944718","id":"PMC_25944718","title":"Upregulation of SYF2 Relates to Retinal Ganglion Cell Apoptosis and Retinal Glia Cell Proliferation After Light-Induced Retinal Damage.","date":"2015","source":"Journal of molecular neuroscience : MN","url":"https://pubmed.ncbi.nlm.nih.gov/25944718","citation_count":7,"is_preprint":false},{"pmid":"31522605","id":"PMC_31522605","title":"Influence of miR-376c-3p/SYF2 Axis on the Progression of Gastric Cancer.","date":"2019","source":"Technology in cancer research & treatment","url":"https://pubmed.ncbi.nlm.nih.gov/31522605","citation_count":7,"is_preprint":false},{"pmid":"24962097","id":"PMC_24962097","title":"Involvement of upregulated SYF2 in Schwann cell differentiation and migration after sciatic nerve crush.","date":"2014","source":"Cellular and molecular neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/24962097","citation_count":6,"is_preprint":false},{"pmid":"30317439","id":"PMC_30317439","title":"Genome-wide identification and functional analysis of the splicing component SYF2/NTC31/p29 across different plant species.","date":"2018","source":"Planta","url":"https://pubmed.ncbi.nlm.nih.gov/30317439","citation_count":6,"is_preprint":false},{"pmid":"32417187","id":"PMC_32417187","title":"MicroRNA-621 inhibits the growth of gastric cancer cells by targeting SYF2.","date":"2020","source":"Archives of biochemistry and biophysics","url":"https://pubmed.ncbi.nlm.nih.gov/32417187","citation_count":5,"is_preprint":false},{"pmid":"38627018","id":"PMC_38627018","title":"The Prp19C/NTC subunit Syf2 and the Prp19C/NTC-associated protein Cwc15 function in TREX occupancy and transcription elongation.","date":"2024","source":"RNA (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/38627018","citation_count":4,"is_preprint":false},{"pmid":"36118875","id":"PMC_36118875","title":"Genome-wide comparison and in silico analysis of splicing factor SYF2/NTC31/p29 in eukaryotes: Special focus on vertebrates.","date":"2022","source":"Frontiers in genetics","url":"https://pubmed.ncbi.nlm.nih.gov/36118875","citation_count":1,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8815,"output_tokens":2524,"usd":0.032153,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9713,"output_tokens":2744,"usd":0.058583,"stage2_stop_reason":"end_turn"},"total_usd":0.090736,"stage1_batch_id":"msgbatch_017qqVz33Ga63SCDwzb35XPb","stage2_batch_id":"msgbatch_01Scr2Ei9x4HJMiRGxwrmvLK","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2020,\n      \"finding\": \"SYF2 is associated with ECT2 pre-mRNA and controls alternative splicing programs in breast cancer cells; SYF2 depletion by RNAi reversed doxorubicin resistance and altered S-phase accumulation in resistant cells. Both SYF2 and ZRANB2 AS programs converged on inclusion of ECT2 exon 5 (ECT2-Ex5+).\",\n      \"method\": \"RNAi screen, RNA-seq, RIP (RNA immunoprecipitation showing SYF2 association with ECT2 pre-mRNA), cell-cycle analysis\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal RIP confirming SYF2–ECT2 pre-mRNA association, RNAi phenotypic rescue, RNA-seq for splicing program; single lab\",\n      \"pmids\": [\"31943118\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Suppression of SYF2, a spliceosome-associated factor, alleviates TDP-43 aggregation and mislocalization, improves TDP-43 activity, and rescues neuronal survival in C9ORF72 and sporadic ALS patient-derived neurons; Syf2 suppression also ameliorates neurodegeneration, neuromuscular junction loss, and motor dysfunction in TDP-43 mice.\",\n      \"method\": \"RNAi/genetic suppression in patient-derived neurons, mouse in vivo loss-of-function (TDP-43 mouse model), bioinformatic chemical/genetic perturbational analysis\",\n      \"journal\": \"Cell stem cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo mouse model plus patient-derived neuron system, multiple ALS genotypes tested; single lab but orthogonal models\",\n      \"pmids\": [\"36736291\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Mouse p29/Syf2/Ntc31 is required for embryonic viability; homozygous knockout causes lethality by E6.5 with decreased Chk1 and α-tubulin mRNA levels (via impaired post-transcriptional regulation), and an aberrant G2/M DNA damage checkpoint response to aphidicolin and UV. Knockdown of the zebrafish ortholog (zfp29) similarly causes embryonic death with reduced acetylated α-tubulin.\",\n      \"method\": \"Gene-trap knockout mouse, siRNA knockdown in zebrafish (morpholino), RT-qPCR for Chk1/α-tubulin mRNAs, checkpoint assay with aphidicolin/UV, rescue by transgenic mp29 re-expression\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo knockout with transgenic rescue, two animal models (mouse and zebrafish), multiple orthogonal readouts\",\n      \"pmids\": [\"22448250\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"SYF2 knockdown in NSCLC A549 cells blocks S-phase entry, inhibits proliferation, and upregulates p21 expression, indicating SYF2 is required for G1/S cell-cycle progression in cancer cells.\",\n      \"method\": \"siRNA knockdown, flow cytometry cell-cycle analysis, Western blot for p21\",\n      \"journal\": \"Pathology, research and practice\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single siRNA approach, no rescue experiment\",\n      \"pmids\": [\"25433998\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"SYF2 knockdown in glioma U87 cells arrests growth at G1 phase and reduces PCNA and cyclin D1 expression, supporting a role for SYF2 in G1/S transition through regulation of cyclin D1 levels.\",\n      \"method\": \"siRNA knockdown, flow cytometry, Western blot for PCNA and cyclin D1\",\n      \"journal\": \"Medical oncology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single siRNA approach, no rescue experiment\",\n      \"pmids\": [\"24985881\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"SYF2 upregulation in astrocytes (C6 cells) after LPS challenge is required for astrocyte activation; SYF2 silencing in C6 cells and PC12 neuronal cells reduced LPS-induced astrocyte activation and neuronal apoptosis, respectively.\",\n      \"method\": \"siRNA knockdown in C6 and PC12 cells, conditioned media apoptosis assay, LPS neuroinflammation rat model\",\n      \"journal\": \"Journal of neuroscience research\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — siRNA knockdown in cell lines, no mechanistic pathway placement beyond cellular phenotype\",\n      \"pmids\": [\"24301298\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"SYF2 is required for Schwann cell migration after sciatic nerve injury; SYF2-specific siRNA transfection in Schwann cells produced shorter, disorganized microtubule structures and decreased cell migration, suggesting SYF2 modulates microtubule dynamics in Schwann cells.\",\n      \"method\": \"siRNA knockdown in primary Schwann cells, immunofluorescence of microtubule structure, migration assay, rat sciatic nerve crush in vivo model\",\n      \"journal\": \"Cellular and molecular neurobiology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, siRNA phenotype in cell culture with in vivo correlative expression; no mechanistic rescue\",\n      \"pmids\": [\"24962097\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"MiR-376c-3p directly targets the SYF2 3'-UTR to reduce SYF2 expression, and SYF2 overexpression abrogates the inhibitory effects of miR-376c-3p on gastric cancer cell proliferation and migration, placing SYF2 downstream of miR-376c-3p in this pathway.\",\n      \"method\": \"Luciferase reporter assay (miRNA–3'UTR targeting), overexpression/knockdown, proliferation and migration assays\",\n      \"journal\": \"Technology in cancer research & treatment\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, luciferase reporter for targeting validation, no deep mechanistic characterization of SYF2 function\",\n      \"pmids\": [\"31522605\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"MiR-621 directly interacts with the SYF2 3'-UTR and post-transcriptionally represses SYF2 expression in gastric cancer cells; SYF2 overexpression reversed the anti-proliferative effects of miR-621, confirming SYF2 is a functional target.\",\n      \"method\": \"Luciferase reporter assay (direct 3'-UTR interaction), gain/loss-of-function experiments, xenograft model\",\n      \"journal\": \"Archives of biochemistry and biophysics\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, luciferase 3'-UTR reporter, rescue experiment but no deep mechanistic characterization of SYF2\",\n      \"pmids\": [\"32417187\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Yeast Syf2, a subunit of the Prp19C/NTC complex, is required for full Prp19C occupancy at transcribed genes and for the interaction between Prp19C and TREX, thereby coupling transcription elongation to nuclear mRNA export. Genetic interaction between Δsyf2 and Δcwc15 confirmed partially overlapping functions in Prp19C–TREX interaction.\",\n      \"method\": \"Chromatin immunoprecipitation (ChIP) for Prp19C and TREX occupancy, co-immunoprecipitation (Co-IP) for Prp19C–TREX interaction, genetic interaction (double deletion analysis), transcription elongation assays in yeast\",\n      \"journal\": \"RNA (New York, N.Y.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP, Co-IP, and genetic epistasis in yeast; multiple orthogonal methods; single lab\",\n      \"pmids\": [\"38627018\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"SYF2 (p29/NTC31/fSAP29) is a conserved spliceosome-associated subunit of the Prp19C/NTC complex that regulates pre-mRNA splicing and alternative splicing programs (including ECT2 exon inclusion), supports full Prp19C occupancy at transcribed genes to couple transcription elongation with nuclear mRNA export via TREX, is required for DNA damage checkpoint responses (Chk1/α-tubulin post-transcriptional regulation), and promotes G1/S cell-cycle progression; its suppression alleviates TDP-43 pathology in ALS models, and it is post-transcriptionally regulated by miR-376c-3p and miR-621 through direct 3'-UTR targeting.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"SYF2 (p29/NTC31) is a conserved subunit of the Prp19C/NTC spliceosome-associated complex that links pre-mRNA splicing and alternative splicing to downstream gene-expression and cell-cycle programs [#0, #9]. In yeast, Syf2 is required for full Prp19C occupancy at transcribed genes and for the Prp19C–TREX interaction, thereby coupling transcription elongation to nuclear mRNA export, with overlapping function shared with Cwc15 [#9]. In mammalian cells SYF2 directs alternative splicing programs, associating with ECT2 pre-mRNA and driving ECT2 exon 5 inclusion, a program convergent with ZRANB2 [#0]. SYF2 is essential for embryonic viability, with loss causing early lethality, reduced Chk1 and α-tubulin mRNA levels, and an aberrant DNA damage checkpoint response [#2]. Across cancer and developmental contexts SYF2 promotes G1/S cell-cycle progression [#0, #2], and its suppression alleviates TDP-43 aggregation, mislocalization, and neurodegeneration in ALS models [#1]. SYF2 is post-transcriptionally repressed through direct 3'-UTR targeting by miR-376c-3p and miR-621 [#7, #8].\",\n  \"teleology\": [\n    {\n      \"year\": 2012,\n      \"claim\": \"Established that SYF2 is essential in vivo and functionally couples post-transcriptional control of Chk1/α-tubulin to the DNA damage checkpoint, moving it beyond a presumed splicing factor to a developmentally required regulator.\",\n      \"evidence\": \"Gene-trap knockout mouse with transgenic rescue, zebrafish morpholino knockdown, RT-qPCR and aphidicolin/UV checkpoint assays\",\n      \"pmids\": [\"22448250\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct molecular mechanism linking SYF2 to Chk1/α-tubulin mRNA stability not resolved\", \"Whether the checkpoint defect is a direct splicing consequence or indirect is unclear\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Linked SYF2 expression to glial/neuronal injury responses, raising a role in neuroinflammation beyond constitutive cell-cycle function.\",\n      \"evidence\": \"siRNA knockdown in C6 astrocyte and PC12 neuronal cell lines, conditioned-media apoptosis assay, LPS rat model\",\n      \"pmids\": [\"24301298\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No mechanistic pathway placement beyond cellular phenotype\", \"No rescue experiment\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Multiple cancer/neural systems converged on SYF2 as a driver of G1/S progression, implicating cyclin D1 and p21 as affected nodes and microtubule dynamics in Schwann cell migration.\",\n      \"evidence\": \"siRNA knockdown with flow cytometry and Western blot (p21, PCNA, cyclin D1) in A549 and U87 cells; siRNA plus microtubule imaging and migration assay in primary Schwann cells with sciatic nerve injury model\",\n      \"pmids\": [\"25433998\", \"24985881\", \"24962097\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Single siRNA approaches without rescue\", \"Whether cyclin D1/p21/microtubule effects are direct splicing targets unknown\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Identified SYF2 as a post-transcriptionally regulated target, with miR-376c-3p directly binding its 3'-UTR to repress proliferation and migration.\",\n      \"evidence\": \"Luciferase 3'-UTR reporter assay, overexpression/knockdown, proliferation and migration assays in gastric cancer cells\",\n      \"pmids\": [\"31522605\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No deep mechanistic characterization of SYF2 downstream function\", \"Single lab\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Connected SYF2's splicing activity to a defined alternative splicing program (ECT2 exon 5 inclusion) and to chemotherapy resistance, defining a mechanistic output of SYF2 in cancer cells; a second study confirmed miR-621 as an additional 3'-UTR repressor.\",\n      \"evidence\": \"RNAi screen, RNA-seq, RIP showing SYF2–ECT2 pre-mRNA association, cell-cycle analysis (idx 0); luciferase 3'-UTR reporter and xenograft rescue (idx 8)\",\n      \"pmids\": [\"31943118\", \"32417187\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct splice-site contacts of SYF2 not mapped\", \"How ECT2-Ex5+ inclusion mediates doxorubicin resistance not fully defined\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Showed that lowering SYF2 is protective in disease, alleviating TDP-43 pathology and neurodegeneration across multiple ALS models, establishing SYF2 as a disease modifier.\",\n      \"evidence\": \"RNAi/genetic suppression in C9ORF72 and sporadic ALS patient-derived neurons, TDP-43 mouse loss-of-function, perturbational bioinformatics\",\n      \"pmids\": [\"36736291\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism connecting SYF2 splicing function to TDP-43 aggregation unresolved\", \"Whether protection is splicing-dependent unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Mechanistically placed Syf2 within Prp19C, showing it is required for Prp19C occupancy at genes and for the Prp19C–TREX interaction, thereby coupling transcription elongation to mRNA export.\",\n      \"evidence\": \"ChIP for Prp19C/TREX occupancy, Co-IP for Prp19C–TREX interaction, Δsyf2/Δcwc15 genetic epistasis, transcription elongation assays in yeast\",\n      \"pmids\": [\"38627018\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Conservation of the Prp19C–TREX coupling role in mammals not demonstrated\", \"Structural basis of Syf2's contribution to Prp19C occupancy unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How SYF2's core role in Prp19C-dependent splicing and transcription–export coupling mechanistically produces its specific phenotypic outputs — checkpoint regulation, G1/S progression, and TDP-43 protection — remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No direct link between splicing activity and Chk1/α-tubulin/cyclin D1 regulation\", \"Mammalian Prp19C–TREX coupling untested\", \"Mechanism of TDP-43 rescue undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140098\", \"supporting_discovery_ids\": [0, 9]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0, 9]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [0, 9]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"complexes\": [\"Prp19C/NTC\"],\n    \"partners\": [\"TREX\", \"CWC15\", \"ECT2\", \"ZRANB2\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"tie","faith_supported":6,"faith_total":6,"faith_pct":100.0}}