{"gene":"SYMPK","run_date":"2026-06-10T10:51:54","timeline":{"discoveries":[{"year":2021,"finding":"SYMPK functions as a scaffold protein required for meiotic progression in male germ cells; germ cell-specific knockout in mice causes spermatocyte defects in homologous chromosome synapsis, DNA double-strand break repair, and meiotic recombination. SYMPK also regulates alternative splicing in spermatogenic cells, including proper splicing of Sun1 pre-mRNA.","method":"Conditional knockout mice (cKO) with Ddx4-Cre and Stra8-Cre drivers; RNA-Seq analysis; immunofluorescence for synapsis and DSB markers","journal":"Frontiers in cell and developmental biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean in vivo KO with defined cellular phenotypes and RNA-Seq, single lab with multiple orthogonal methods","pmids":["34434935"],"is_preprint":false},{"year":2019,"finding":"SYMPK interacts directly with the pluripotency factor Oct4 via its DUF3453 domain in mouse embryonic stem cells; this interaction promotes ESC self-renewal, colony formation, and pluripotency. Deletion of DUF3453 impairs colony formation, placing SYMPK upstream of Oct4-dependent transcriptional programs.","method":"Co-immunoprecipitation; CRISPR/Cas9 deletion; overexpression; teratoma and chimeric mouse assays; domain deletion analysis","journal":"Stem cells (Dayton, Ohio)","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — Co-IP with domain deletion validation, in vivo functional assays, single lab","pmids":["30801858"],"is_preprint":false},{"year":2026,"finding":"SYMPK dynamically localizes to spindle microtubules during oocyte meiotic maturation following germinal vesicle breakdown. Oocyte-specific Sympk knockout causes complete female infertility, metaphase I arrest, disorganized spindle architecture, and destabilized kinetochore-microtubule attachments with persistent spindle assembly checkpoint (SAC) activation. Mechanistically, immunoprecipitation-mass spectrometry revealed that SYMPK interacts with spindle regulators KIF20A and NUMA1 in MI oocytes and is required for their proper spindle localization.","method":"Oocyte-specific conditional knockout mice; live imaging; immunofluorescence; chromosome spreads; pharmacologic SAC inhibition; immunoprecipitation-mass spectrometry","journal":"Journal of genetics and genomics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo KO with defined spindle phenotype plus IP-MS identification of interactors and localization rescue experiments, single lab with multiple orthogonal methods","pmids":["41520922"],"is_preprint":false}],"current_model":"SYMPK (Symplekin) is a scaffold protein that, beyond its established role in polyadenylation machinery assembly, directly interacts with Oct4 (via its DUF3453 domain) to promote embryonic stem cell self-renewal, regulates pre-mRNA alternative splicing (including Sun1) in male germ cells to support meiotic progression, and localizes to spindle microtubules in oocytes where it scaffolds KIF20A and NUMA1 to coordinate acentrosomal spindle organization during female meiosis."},"narrative":{"mechanistic_narrative":"SYMPK (Symplekin) is a scaffold protein that supports germ cell development and pluripotency through context-specific protein interactions and RNA processing [PMID:34434935, PMID:30801858, PMID:41520922]. In male germ cells, SYMPK is required for meiotic progression: its loss disrupts homologous chromosome synapsis, DNA double-strand break repair, and meiotic recombination, and it regulates alternative splicing of pre-mRNAs including Sun1 in spermatogenic cells [PMID:34434935]. In embryonic stem cells, SYMPK binds the pluripotency factor Oct4 directly through its DUF3453 domain, acting upstream of Oct4-dependent transcriptional programs to promote self-renewal and colony formation [PMID:30801858]. During female meiosis, SYMPK localizes dynamically to spindle microtubules after germinal vesicle breakdown and scaffolds the spindle regulators KIF20A and NUMA1, with its loss causing metaphase I arrest, disorganized spindle architecture, destabilized kinetochore-microtubule attachments, persistent spindle assembly checkpoint activation, and complete female infertility [PMID:41520922]. Beyond these contexts, the structural and biochemical basis of SYMPK scaffolding has not been further characterized in the available corpus.","teleology":[{"year":2019,"claim":"Established that SYMPK acts beyond RNA processing as a direct partner of a pluripotency factor, linking it to stem cell self-renewal.","evidence":"Co-immunoprecipitation, CRISPR/Cas9 and domain deletion, and teratoma/chimeric mouse assays in mouse ESCs","pmids":["30801858"],"confidence":"Medium","gaps":["Structural basis of the DUF3453-Oct4 interaction not resolved","Reciprocal validation of the interaction and direct transcriptional targets not defined","Whether RNA-processing function contributes to the ESC phenotype unaddressed"]},{"year":2021,"claim":"Defined an in vivo requirement for SYMPK in male meiosis and tied its function to alternative splicing of meiotic transcripts.","evidence":"Germ cell-specific conditional knockout mice with RNA-Seq and immunofluorescence for synapsis and DSB markers","pmids":["34434935"],"confidence":"Medium","gaps":["Direct splicing mechanism on Sun1 and other targets not biochemically reconstituted","Causal link between specific mis-splicing events and synapsis/recombination defects not established","Protein partners mediating the splicing role in spermatocytes not identified"]},{"year":2026,"claim":"Revealed a non-RNA scaffolding role for SYMPK at the acentrosomal meiotic spindle, coordinating spindle regulators required for chromosome segregation fidelity.","evidence":"Oocyte-specific conditional knockout with live imaging, chromosome spreads, pharmacologic SAC inhibition, and IP-MS identification of KIF20A and NUMA1","pmids":["41520922"],"confidence":"Medium","gaps":["Whether SYMPK directly binds KIF20A and NUMA1 versus indirectly is unresolved by IP-MS alone","Mechanism by which SYMPK is recruited to spindle microtubules unknown","Relationship between the spindle scaffolding role and SYMPK's polyadenylation/splicing functions undefined"]},{"year":null,"claim":"How a single scaffold protein switches between RNA-processing, transcription factor binding, and spindle organization across cell types remains unresolved.","evidence":"No discovery in the corpus integrates these context-specific roles mechanistically","pmids":[],"confidence":"Medium","gaps":["No unifying structural or biochemical model linking the distinct activities","Domain requirements for the spindle and splicing roles not mapped","Direct versus scaffold-mediated nature of most interactions unconfirmed"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[1,2]}],"localization":[],"pathway":[{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[0,2]}],"complexes":[],"partners":["POU5F1","KIF20A","NUMA1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q92797","full_name":"Symplekin","aliases":[],"length_aa":1274,"mass_kda":141.1,"function":"Scaffold protein that functions as a component of a multimolecular complex involved in histone mRNA 3'-end processing. Specific component of the tight junction (TJ) plaque, but might not be an exclusively junctional component. May have a house-keeping rule. Is involved in pre-mRNA polyadenylation. Enhances SSU72 phosphatase activity","subcellular_location":"Cytoplasm, cytoskeleton; Cell junction, tight junction; Cell membrane; Cell junction; Nucleus, nucleoplasm","url":"https://www.uniprot.org/uniprotkb/Q92797/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/SYMPK","classification":"Common Essential","n_dependent_lines":1201,"n_total_lines":1208,"dependency_fraction":0.9942052980132451},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CPSF6","stoichiometry":0.2},{"gene":"RBM14","stoichiometry":0.2},{"gene":"SNRPA","stoichiometry":0.2},{"gene":"SNRPB","stoichiometry":0.2},{"gene":"SSRP1","stoichiometry":0.2},{"gene":"TOP1","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/SYMPK","total_profiled":1310},"omim":[{"mim_id":"602388","title":"SYMPLEKIN; SYMPK","url":"https://www.omim.org/entry/602388"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"},{"location":"Plasma membrane","reliability":"Additional"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/SYMPK"},"hgnc":{"alias_symbol":["SYM","SPK","Pta1"],"prev_symbol":[]},"alphafold":{"accession":"Q92797","domains":[{"cath_id":"1.25.40","chopping":"556-662","consensus_level":"medium","plddt":86.7941,"start":556,"end":662}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q92797","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q92797-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q92797-F1-predicted_aligned_error_v6.png","plddt_mean":74.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=SYMPK","jax_strain_url":"https://www.jax.org/strain/search?query=SYMPK"},"sequence":{"accession":"Q92797","fasta_url":"https://rest.uniprot.org/uniprotkb/Q92797.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q92797/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q92797"}},"corpus_meta":[{"pmid":"18322526","id":"PMC_18322526","title":"The MC-Fold and MC-Sym pipeline infers RNA structure from sequence data.","date":"2008","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/18322526","citation_count":623,"is_preprint":false},{"pmid":"24276795","id":"PMC_24276795","title":"Promoters in the nodulation region of the Rhizobium leguminosarum Sym plasmid pRL1JI.","date":"1987","source":"Plant molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/24276795","citation_count":572,"is_preprint":false},{"pmid":"23344641","id":"PMC_23344641","title":"SyM-BBB: a microfluidic Blood Brain Barrier model.","date":"2013","source":"Lab on a chip","url":"https://pubmed.ncbi.nlm.nih.gov/23344641","citation_count":243,"is_preprint":false},{"pmid":"10681506","id":"PMC_10681506","title":"Poliovirus RNA-dependent RNA polymerase (3D(pol)). Assembly of stable, elongation-competent complexes by using a symmetrical primer-template substrate (sym/sub).","date":"2000","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10681506","citation_count":124,"is_preprint":false},{"pmid":"8412662","id":"PMC_8412662","title":"Molecular cloning and characterization of a sym plasmid locus that regulates cultivar-specific nodulation of soybean by Rhizobium fredii USDA257.","date":"1993","source":"Molecular microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/8412662","citation_count":99,"is_preprint":false},{"pmid":"3539915","id":"PMC_3539915","title":"Induction of the nodA promoter of Rhizobium leguminosarum Sym plasmid pRL1JI by plant flavanones and flavones.","date":"1987","source":"Journal of bacteriology","url":"https://pubmed.ncbi.nlm.nih.gov/3539915","citation_count":94,"is_preprint":false},{"pmid":"8996224","id":"PMC_8996224","title":"(2S,4R)-4-methylglutamic acid (SYM 2081): a selective, 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EHRENBERG, 1831).","date":"2011","source":"European journal of protistology","url":"https://pubmed.ncbi.nlm.nih.gov/23195567","citation_count":15,"is_preprint":false},{"pmid":"23472585","id":"PMC_23472585","title":"Biological activity of sym-triazines with acetylcholine-like substitutions as multitarget modulators of Alzheimer's disease.","date":"2013","source":"ACS chemical neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/23472585","citation_count":14,"is_preprint":false},{"pmid":"19923914","id":"PMC_19923914","title":"C. elegans sym-1 is a downstream target of the hunchback-like-1 developmental timing transcription factor.","date":"2009","source":"Cell cycle (Georgetown, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/19923914","citation_count":12,"is_preprint":false},{"pmid":"6208314","id":"PMC_6208314","title":"Comparative studies of rabies and Sindbis virus replication in human neuroblastoma (SYM-I) cells that can produce interferon.","date":"1984","source":"The Journal of general virology","url":"https://pubmed.ncbi.nlm.nih.gov/6208314","citation_count":12,"is_preprint":false},{"pmid":"7470060","id":"PMC_7470060","title":"Enzymic synthesis of sym-homospermidine in Lathyrus sativus (grass pea) seedlings.","date":"1980","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/7470060","citation_count":10,"is_preprint":false},{"pmid":"34434935","id":"PMC_34434935","title":"SYMPK Is Required for Meiosis and Involved in Alternative Splicing in Male Germ Cells.","date":"2021","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/34434935","citation_count":9,"is_preprint":false},{"pmid":"21798296","id":"PMC_21798296","title":"RNA2 of TRV SYM breaks the rules for tobravirus genome structure.","date":"2011","source":"Virus research","url":"https://pubmed.ncbi.nlm.nih.gov/21798296","citation_count":9,"is_preprint":false},{"pmid":"8012570","id":"PMC_8012570","title":"Sequence and regulation of psrA, a gene on the Sym plasmid of Rhizobium leguminosarum biover phaseoli which inhibits transcription of the psi genes.","date":"1994","source":"Microbiology (Reading, England)","url":"https://pubmed.ncbi.nlm.nih.gov/8012570","citation_count":9,"is_preprint":false},{"pmid":"16653124","id":"PMC_16653124","title":"Pleiotropic Effects of sym-17 : A Mutation in Pisum sativum L. cv Sparkle Causes Decreased Nodulation, Altered Root and Shoot Growth, and Increased Ethylene Production.","date":"1992","source":"Plant physiology","url":"https://pubmed.ncbi.nlm.nih.gov/16653124","citation_count":9,"is_preprint":false},{"pmid":"9437519","id":"PMC_9437519","title":"Dimethyldioxirane converts benzene oxide/oxepin into (Z,Z)-muconaldehyde and sym-oxepin oxide: modeling the metabolism of benzene and its photooxidative degradation.","date":"1997","source":"Chemical research in toxicology","url":"https://pubmed.ncbi.nlm.nih.gov/9437519","citation_count":9,"is_preprint":false},{"pmid":"16346803","id":"PMC_16346803","title":"Effect of Sym Plasmid Curing on Symbiotic Effectiveness in Rhizobium fredii.","date":"1985","source":"Applied and environmental microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/16346803","citation_count":8,"is_preprint":false},{"pmid":"26159623","id":"PMC_26159623","title":"A single sym plasmid type predominates across diverse chromosomal lineages of Cupriavidus nodule symbionts.","date":"2015","source":"Systematic and applied microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/26159623","citation_count":7,"is_preprint":false},{"pmid":"2033052","id":"PMC_2033052","title":"Distribution of O-acetyl groups in the exopolysaccharide synthesized by Rhizobium leguminosarum strains is not determined by the Sym plasmid.","date":"1991","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/2033052","citation_count":7,"is_preprint":false},{"pmid":"33110161","id":"PMC_33110161","title":"The pseudogene problem and RT-qPCR data normalization; SYMPK: a suitable reference gene for papillary thyroid carcinoma.","date":"2020","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/33110161","citation_count":6,"is_preprint":false},{"pmid":"26435892","id":"PMC_26435892","title":"Amino acids in sandal (Santalum album L) with special reference to cis-4-hydroxy-l-proline and sym. homospermidine.","date":"2015","source":"SpringerPlus","url":"https://pubmed.ncbi.nlm.nih.gov/26435892","citation_count":5,"is_preprint":false},{"pmid":"40508264","id":"PMC_40508264","title":"The IAA-Producing Rhizobacterium Bacillus sp. SYM-4 Promotes Maize Growth and Yield.","date":"2025","source":"Plants (Basel, Switzerland)","url":"https://pubmed.ncbi.nlm.nih.gov/40508264","citation_count":5,"is_preprint":false},{"pmid":"30801858","id":"PMC_30801858","title":"Interaction Between Sympk and Oct4 Promotes Mouse Embryonic Stem Cell Proliferation.","date":"2019","source":"Stem cells (Dayton, Ohio)","url":"https://pubmed.ncbi.nlm.nih.gov/30801858","citation_count":3,"is_preprint":false},{"pmid":"38069024","id":"PMC_38069024","title":"Impacts of Natural Selection on Evolution of Core and Symbiotically Specialized (sym) Genes in the Polytypic Species Neorhizobium galegae.","date":"2023","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/38069024","citation_count":3,"is_preprint":false},{"pmid":"4088877","id":"PMC_4088877","title":"Inhibition of the activities of DNA primase-polymerase alpha complex from KB cells by hexasodium sym-bis(m-aminobenzoyl-m-amino-p-methylbenzoyl-1-naphthylamino-4 ,6,8-trisulfonate)carbamide.","date":"1985","source":"Nucleic acids symposium series","url":"https://pubmed.ncbi.nlm.nih.gov/4088877","citation_count":3,"is_preprint":false},{"pmid":"24272399","id":"PMC_24272399","title":"Characterization of Sym plasmids of Rhizobium leguminosarum strains able to nodulate Pisum sativum cv Afghanistan.","date":"1988","source":"Plant molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/24272399","citation_count":3,"is_preprint":false},{"pmid":"33554054","id":"PMC_33554054","title":"sym-2 loss-of-function causes glutamatergic neurodegeneration after oxidative stress.","date":"2021","source":"microPublication biology","url":"https://pubmed.ncbi.nlm.nih.gov/33554054","citation_count":2,"is_preprint":false},{"pmid":"1714314","id":"PMC_1714314","title":"An altered constitutive peptide in sym 5 mutants of Pisum sativum L.","date":"1990","source":"Plant molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/1714314","citation_count":2,"is_preprint":false},{"pmid":"41520922","id":"PMC_41520922","title":"SYMPK interacts with KIF20A and NUMA1 to coordinate spindle organization and safeguard oocyte meiotic maturation.","date":"2026","source":"Journal of genetics and genomics = Yi chuan xue bao","url":"https://pubmed.ncbi.nlm.nih.gov/41520922","citation_count":1,"is_preprint":false},{"pmid":"18368313","id":"PMC_18368313","title":"The function of three indigenous plasmids in Mesorhizobium huakuii 2020 and its symbiotic interaction with Sym pJB5JI of Rhizobium leguminosarum.","date":"2008","source":"Science in China. Series C, Life sciences","url":"https://pubmed.ncbi.nlm.nih.gov/18368313","citation_count":1,"is_preprint":false},{"pmid":"37532583","id":"PMC_37532583","title":"A new metabolic pathway for sym-homospermidine synthesis in an extreme thermophile, Thermus thermophilus.","date":"2023","source":"The Journal of general and applied microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/37532583","citation_count":0,"is_preprint":false},{"pmid":"40750654","id":"PMC_40750654","title":"A non-canonical fungal peroxisome PTS-1 signal, SYM, and its evolutionary aspects.","date":"2025","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/40750654","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.08.29.672641","title":"Enzyme-powered DNA origami nanostructures for enhanced mucosal diffusion","date":"2025-09-04","source":"bioRxiv","url":"https://doi.org/10.1101/2025.08.29.672641","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.08.05.606452","title":"Prenatal Dexamethasone Programs Autonomic Dysregulation in Female Rats","date":"2024-08-07","source":"bioRxiv","url":"https://doi.org/10.1101/2024.08.05.606452","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.03.10.25323701","title":"Abnormal gastric electrophysiology following laparoscopic sleeve gastrectomy and associations with symptoms and quality of life","date":"2025-03-11","source":"bioRxiv","url":"https://doi.org/10.1101/2025.03.10.25323701","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.09.25.24314370","title":"Gastrointestinal Dysmotility, Autonomic Function and Small Intestinal Bacterial Overgrowth Among People with Well-Controlled HIV","date":"2024-09-26","source":"bioRxiv","url":"https://doi.org/10.1101/2024.09.25.24314370","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.10.28.24316164","title":"SymScore: Machine Learning Accuracy Meets Transparency in a Symbolic Regression-Based Clinical Score Generator","date":"2024-11-04","source":"bioRxiv","url":"https://doi.org/10.1101/2024.10.28.24316164","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.09.24.614653","title":"BRDKRM: An Explainable Framework for Disease Modifying Drug Identification","date":"2024-09-26","source":"bioRxiv","url":"https://doi.org/10.1101/2024.09.24.614653","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.03.17.643812","title":"Rapid canalisation of mandible structure in Tetrapoda","date":"2025-03-18","source":"bioRxiv","url":"https://doi.org/10.1101/2025.03.17.643812","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":30309,"output_tokens":1193,"usd":0.054411,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":7461,"output_tokens":1661,"usd":0.039415,"stage2_stop_reason":"end_turn"},"total_usd":0.093826,"stage1_batch_id":"msgbatch_017qqVz33Ga63SCDwzb35XPb","stage2_batch_id":"msgbatch_01Scr2Ei9x4HJMiRGxwrmvLK","note":"batch pricing = 50% of standard"},"stage1_raw":"Looking through the abstracts, I need to identify papers about the human/mammalian gene SYMPK (Symplekin). Let me classify each paper:\n\n- Papers 1-15, 16-35, 37-46, 48-52, 54-56, 57-63: These are about RNA structure algorithms, Rhizobium sym plasmids, kainate receptor ligands, C. elegans sym genes (different gene), BBB models, polyamine synthesis, virus replication, etc. — NOT about human SYMPK protein.\n- Paper 36 (PMID:34434935): \"SYMPK Is Required for Meiosis...\" — directly about mammalian SYMPK\n- Paper 47 (PMID:30801858): \"Interaction Between Sympk and Oct4...\" — directly about mammalian SYMPK\n- Paper 53 (PMID:41520922): \"SYMPK interacts with KIF20A and NUMA1...\" — directly about mammalian SYMPK\n- Paper 44 (PMID:33110161): About SYMPK as reference gene — expression study, no mechanism\n\n```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2021,\n      \"finding\": \"SYMPK functions as a scaffold protein required for meiotic progression in male germ cells; germ cell-specific knockout in mice causes spermatocyte defects in homologous chromosome synapsis, DNA double-strand break repair, and meiotic recombination. SYMPK also regulates alternative splicing in spermatogenic cells, including proper splicing of Sun1 pre-mRNA.\",\n      \"method\": \"Conditional knockout mice (cKO) with Ddx4-Cre and Stra8-Cre drivers; RNA-Seq analysis; immunofluorescence for synapsis and DSB markers\",\n      \"journal\": \"Frontiers in cell and developmental biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean in vivo KO with defined cellular phenotypes and RNA-Seq, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"34434935\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"SYMPK interacts directly with the pluripotency factor Oct4 via its DUF3453 domain in mouse embryonic stem cells; this interaction promotes ESC self-renewal, colony formation, and pluripotency. Deletion of DUF3453 impairs colony formation, placing SYMPK upstream of Oct4-dependent transcriptional programs.\",\n      \"method\": \"Co-immunoprecipitation; CRISPR/Cas9 deletion; overexpression; teratoma and chimeric mouse assays; domain deletion analysis\",\n      \"journal\": \"Stem cells (Dayton, Ohio)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — Co-IP with domain deletion validation, in vivo functional assays, single lab\",\n      \"pmids\": [\"30801858\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"SYMPK dynamically localizes to spindle microtubules during oocyte meiotic maturation following germinal vesicle breakdown. Oocyte-specific Sympk knockout causes complete female infertility, metaphase I arrest, disorganized spindle architecture, and destabilized kinetochore-microtubule attachments with persistent spindle assembly checkpoint (SAC) activation. Mechanistically, immunoprecipitation-mass spectrometry revealed that SYMPK interacts with spindle regulators KIF20A and NUMA1 in MI oocytes and is required for their proper spindle localization.\",\n      \"method\": \"Oocyte-specific conditional knockout mice; live imaging; immunofluorescence; chromosome spreads; pharmacologic SAC inhibition; immunoprecipitation-mass spectrometry\",\n      \"journal\": \"Journal of genetics and genomics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo KO with defined spindle phenotype plus IP-MS identification of interactors and localization rescue experiments, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"41520922\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"SYMPK (Symplekin) is a scaffold protein that, beyond its established role in polyadenylation machinery assembly, directly interacts with Oct4 (via its DUF3453 domain) to promote embryonic stem cell self-renewal, regulates pre-mRNA alternative splicing (including Sun1) in male germ cells to support meiotic progression, and localizes to spindle microtubules in oocytes where it scaffolds KIF20A and NUMA1 to coordinate acentrosomal spindle organization during female meiosis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"SYMPK (Symplekin) is a scaffold protein that supports germ cell development and pluripotency through context-specific protein interactions and RNA processing [#0, #1, #2]. In male germ cells, SYMPK is required for meiotic progression: its loss disrupts homologous chromosome synapsis, DNA double-strand break repair, and meiotic recombination, and it regulates alternative splicing of pre-mRNAs including Sun1 in spermatogenic cells [#0]. In embryonic stem cells, SYMPK binds the pluripotency factor Oct4 directly through its DUF3453 domain, acting upstream of Oct4-dependent transcriptional programs to promote self-renewal and colony formation [#1]. During female meiosis, SYMPK localizes dynamically to spindle microtubules after germinal vesicle breakdown and scaffolds the spindle regulators KIF20A and NUMA1, with its loss causing metaphase I arrest, disorganized spindle architecture, destabilized kinetochore-microtubule attachments, persistent spindle assembly checkpoint activation, and complete female infertility [#2]. Beyond these contexts, the structural and biochemical basis of SYMPK scaffolding has not been further characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2019,\n      \"claim\": \"Established that SYMPK acts beyond RNA processing as a direct partner of a pluripotency factor, linking it to stem cell self-renewal.\",\n      \"evidence\": \"Co-immunoprecipitation, CRISPR/Cas9 and domain deletion, and teratoma/chimeric mouse assays in mouse ESCs\",\n      \"pmids\": [\"30801858\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Structural basis of the DUF3453-Oct4 interaction not resolved\", \"Reciprocal validation of the interaction and direct transcriptional targets not defined\", \"Whether RNA-processing function contributes to the ESC phenotype unaddressed\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Defined an in vivo requirement for SYMPK in male meiosis and tied its function to alternative splicing of meiotic transcripts.\",\n      \"evidence\": \"Germ cell-specific conditional knockout mice with RNA-Seq and immunofluorescence for synapsis and DSB markers\",\n      \"pmids\": [\"34434935\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct splicing mechanism on Sun1 and other targets not biochemically reconstituted\", \"Causal link between specific mis-splicing events and synapsis/recombination defects not established\", \"Protein partners mediating the splicing role in spermatocytes not identified\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Revealed a non-RNA scaffolding role for SYMPK at the acentrosomal meiotic spindle, coordinating spindle regulators required for chromosome segregation fidelity.\",\n      \"evidence\": \"Oocyte-specific conditional knockout with live imaging, chromosome spreads, pharmacologic SAC inhibition, and IP-MS identification of KIF20A and NUMA1\",\n      \"pmids\": [\"41520922\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether SYMPK directly binds KIF20A and NUMA1 versus indirectly is unresolved by IP-MS alone\", \"Mechanism by which SYMPK is recruited to spindle microtubules unknown\", \"Relationship between the spindle scaffolding role and SYMPK's polyadenylation/splicing functions undefined\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How a single scaffold protein switches between RNA-processing, transcription factor binding, and spindle organization across cell types remains unresolved.\",\n      \"evidence\": \"No discovery in the corpus integrates these context-specific roles mechanistically\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unifying structural or biochemical model linking the distinct activities\", \"Domain requirements for the spindle and splicing roles not mapped\", \"Direct versus scaffold-mediated nature of most interactions unconfirmed\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [1, 2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005819\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [0, 2]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"POU5F1\", \"KIF20A\", \"NUMA1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":4,"faith_total":4,"faith_pct":100.0}}