{"gene":"SSX2IP","run_date":"2026-06-10T07:46:41","timeline":{"discoveries":[{"year":2002,"finding":"SSX2IP was identified as a direct binding partner of SSX2 via yeast two-hybrid screening, and the interaction was confirmed by GST pull-down assay in vitro. SSX2IP interacts with the N-terminal moiety of SSX2. SSX2IP colocalizes with SSX2 in the nucleus of transfected cells.","method":"Yeast two-hybrid, GST pull-down assay, immunofluorescence of transfected cells","journal":"Genes, chromosomes & cancer","confidence":"Medium","confidence_rationale":"Tier 1–2 / Moderate — in vitro GST pull-down confirmed yeast two-hybrid interaction, two orthogonal methods, single lab","pmids":["12007189"],"is_preprint":false},{"year":2013,"finding":"SSX2IP accumulates at spindle poles in a Dynein-dependent manner in Xenopus egg extracts, interacts with the γ-tubulin ring complex (γ-TuRC) and centriolar satellite protein PCM-1. Immunodepletion of SSX2IP impedes γ-TuRC loading onto centrosomes, leading to reduced microtubule nucleation and spindle assembly failure. In medaka blastomeres and somatic cells, SSX2IP knockdown causes fragmentation of pericentriolar material and chromosome segregation errors, establishing SSX2IP as a centrosome maturation and maintenance factor.","method":"Quantitative proteomics, immunodepletion in Xenopus egg extracts, co-immunoprecipitation, morpholino knockdown in medaka embryos, siRNA knockdown in somatic cells","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal co-IP, immunodepletion with functional rescue, multiple model systems (Xenopus, medaka, somatic cells), multiple orthogonal methods","pmids":["23816619"],"is_preprint":false},{"year":2013,"finding":"SSX2IP localizes to the basal body of primary cilia in human and murine ciliated cells. siRNA knockdown of SSX2IP in human cells reduces recruitment of Cep290 to both centriolar satellites and the basal body, drastically reduces entry of the BBSome and Rab8 accumulation at the ciliary base, limits targeting of the ciliary membrane protein somatostatin receptor 3, and significantly reduces axoneme length. SSX2IP is thus a targeting factor for ciliary membrane proteins that cooperates with Cep290, the BBSome, and Rab8.","method":"siRNA knockdown, immunofluorescence, localization studies in human and murine ciliated cells","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean siRNA KD with multiple specific downstream readouts (Cep290, BBSome, Rab8, somatostatin receptor 3), replicated across human and murine systems","pmids":["24356449"],"is_preprint":false},{"year":2014,"finding":"hMsd1/SSX2IP is delivered to the centrosome in a centriolar satellite-dependent manner and binds the γ-tubulin complex. Depletion of hMsd1/SSX2IP leads to disorganized interphase microtubules and misoriented mitotic spindles with reduced length, establishing SSX2IP as a microtubule-anchoring protein. Knockdown of the zebrafish orthologue causes ciliary defects and disturbed left-right asymmetry, confirming a conserved role in ciliogenesis.","method":"siRNA knockdown, co-immunoprecipitation, immunofluorescence, zebrafish morpholino knockdown","journal":"EMBO reports","confidence":"High","confidence_rationale":"Tier 2 / Strong — co-IP for γ-tubulin binding, siRNA depletion phenotype replicated in zebrafish morpholino model, multiple orthogonal readouts","pmids":["24397932"],"is_preprint":false},{"year":2015,"finding":"hMsd1/SSX2IP-mediated microtubule anchoring to the centrosome is essential for proper centriole assembly and duplication. Upon hMsd1/SSX2IP knockdown, centriolar satellites become stuck at the microtubule minus end near the centrosome and accumulate centrosomal proteins ectopically. Microtubule structures (even when not properly anchored) are still required for satellite aggregation. Superresolution and electron microscopy revealed faulty centriole structures under these conditions. SSX2IP-depleted cells are insensitive to Plk4 overproduction-induced ectopic centriole formation but accelerate centrosome reduplication upon hydroxyurea arrest.","method":"siRNA knockdown, superresolution microscopy, electron microscopy, Plk4 overexpression epistasis, hydroxyurea arrest","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — multiple orthogonal methods including electron microscopy and superresolution, genetic epistasis with Plk4, single lab but thorough experimental design","pmids":["25833712"],"is_preprint":false},{"year":2015,"finding":"Wdr8 constitutively localizes to the proximal end of the mother centriole and forms a complex with hMsd1/SSX2IP identified by mass spectrometry. Wdr8 depletion reduces recruitment of hMsd1/SSX2IP to the mitotic centrosome (but not vice versa), and knockdown of either protein produces similar spindle defects (shortened and misoriented spindle microtubules), placing Wdr8 upstream of hMsd1/SSX2IP in centrosome function.","method":"Mass spectrometry, co-immunoprecipitation, siRNA knockdown, superresolution microscopy, immunofluorescence","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP confirmed by MS, epistasis by sequential knockdown, single lab","pmids":["26545777"],"is_preprint":false},{"year":2021,"finding":"Targeted proximity biotinylation identified SSX2IP as a binding partner of the N-terminal domain of Wtip (a LIM-domain adaptor). Physical association was confirmed and the two proteins formed mixed aggregates upon overexpression. Double depletion of Wtip and SSX2IP in Xenopus embryos disrupted neural tube closure, indicating a functional interaction during neurulation and cell junction remodeling.","method":"Targeted proximity biotinylation (BirA-anti-GFP), co-expression aggregation assay, double morpholino knockdown in Xenopus embryos","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — proximity biotinylation plus co-expression validation plus in vivo double-KD epistasis, single lab, limited biochemical depth","pmids":["34710136"],"is_preprint":false},{"year":2024,"finding":"SSX2IP physically interacts with FANCI (FA Complementation Group I) as confirmed by co-immunoprecipitation. SSX2IP positively regulates FANCI expression, and FANCI overexpression partially rescues the anti-proliferative and anti-migratory effects of SSX2IP knockdown in breast cancer cells, placing SSX2IP upstream of FANCI in a pro-tumorigenic pathway.","method":"Co-immunoprecipitation, siRNA knockdown, overexpression rescue, functional proliferation/migration assays, xenograft","journal":"Cell biology international","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — co-IP plus rescue epistasis, single lab, no deep biochemical characterization of the interaction","pmids":["39533770"],"is_preprint":false},{"year":2026,"finding":"SSX2IP was confirmed as a direct transcriptional/functional target of miR-625-3p by reporter assays, and its upregulation promotes cisplatin export via extracellular vesicles in ovarian cancer cells, thereby enhancing cisplatin resistance. Mass spectrometry and high-speed confocal microscopy supported SSX2IP's role in mediating EV-based cisplatin secretion.","method":"Luciferase reporter assay, mass spectrometry, high-speed confocal microscopy, cell death ELISA, in vitro and in vivo functional assays","journal":"Cancers","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — reporter assay plus MS plus confocal imaging, single lab, functional consequence defined","pmids":["41827805"],"is_preprint":false}],"current_model":"SSX2IP (hMsd1) is a centriolar satellite protein that is delivered to the centrosome in a centriolar satellite-dependent manner where it binds the γ-tubulin ring complex to anchor microtubules, promotes centrosome maturation and centriole assembly, is required for proper mitotic spindle orientation and length (functioning downstream of the centrosomal protein Wdr8), and acts as a targeting factor for ciliary membrane proteins by recruiting Cep290 to the basal body and facilitating BBSome/Rab8-dependent cargo delivery to primary cilia; additionally, SSX2IP directly interacts with SSX2 via its N-terminus, associates with the LIM-domain adaptor Wtip during neural tube closure, and in cancer contexts physically engages FANCI to promote proliferation and migration and mediates extracellular vesicle export of cisplatin to confer drug resistance."},"narrative":{"mechanistic_narrative":"SSX2IP (hMsd1) is a centriolar satellite protein that governs centrosome maturation, microtubule anchoring, and ciliogenesis [PMID:23816619, PMID:25833712]. Delivered to the centrosome in a centriolar satellite-dependent manner, it accumulates at spindle poles via Dynein and binds the γ-tubulin ring complex (γ-TuRC) together with the satellite protein PCM-1, and its loss prevents γ-TuRC loading onto centrosomes, reducing microtubule nucleation and causing spindle assembly failure, pericentriolar material fragmentation, and chromosome segregation errors [PMID:23816619]. By anchoring microtubule minus ends at the centrosome it organizes interphase microtubules, sets mitotic spindle length and orientation, and is required for proper centriole assembly and duplication, with its depletion trapping satellites near the centrosome and producing faulty centriole structures [PMID:25833712]. SSX2IP functions downstream of Wdr8, which localizes to the proximal mother centriole and is required to recruit SSX2IP to the mitotic centrosome [PMID:26545777]. At the basal body, SSX2IP acts as a targeting factor for ciliary membrane proteins, recruiting Cep290 and enabling BBSome entry, Rab8 accumulation, somatostatin receptor 3 delivery, and axoneme elongation, and its orthologs are required for ciliogenesis and left-right asymmetry [PMID:24356449, PMID:24397932]. Originally identified as a nuclear binding partner of the cancer-testis antigen SSX2 through its N-terminus [PMID:12007189], SSX2IP also associates with the LIM-domain adaptor Wtip during Xenopus neural tube closure [PMID:34710136], and in cancer it engages FANCI to promote proliferation and migration [PMID:39533770] and mediates extracellular-vesicle export of cisplatin to confer drug resistance [PMID:41827805].","teleology":[{"year":2002,"claim":"Established the first molecular partner of SSX2IP, defining it as an SSX2-interacting nuclear protein and naming the gene.","evidence":"Yeast two-hybrid screen with GST pull-down confirmation and immunofluorescence of transfected cells","pmids":["12007189"],"confidence":"Medium","gaps":["Functional consequence of the SSX2 interaction undefined","No endogenous validation beyond transfected cells","Binding region on SSX2IP not mapped"]},{"year":2013,"claim":"Answered what SSX2IP does at the centrosome by showing it binds the γ-TuRC and is required for its loading, establishing SSX2IP as a centrosome maturation factor.","evidence":"Quantitative proteomics, immunodepletion in Xenopus egg extracts, reciprocal co-IP, and morpholino/siRNA knockdown across medaka and somatic cells","pmids":["23816619"],"confidence":"High","gaps":["Direct versus indirect γ-TuRC binding not resolved","How Dynein-dependent pole accumulation is regulated unclear"]},{"year":2013,"claim":"Extended SSX2IP function to the cilium, defining it as a basal-body targeting factor that recruits Cep290 and enables BBSome/Rab8-dependent ciliary cargo delivery.","evidence":"siRNA knockdown with immunofluorescent readouts of Cep290, BBSome, Rab8, and somatostatin receptor 3 in human and murine ciliated cells","pmids":["24356449"],"confidence":"High","gaps":["Direct binding partner among Cep290/BBSome not biochemically mapped","Mechanism linking satellite delivery to basal-body targeting unresolved"]},{"year":2014,"claim":"Connected the centrosomal and ciliary roles by showing satellite-dependent delivery and γ-tubulin binding anchor microtubules, controlling spindle orientation and conserved ciliogenesis.","evidence":"siRNA depletion, co-IP for γ-tubulin, and zebrafish morpholino knockdown with left-right asymmetry readouts","pmids":["24397932"],"confidence":"High","gaps":["Molecular basis of microtubule anchoring not structurally defined","Link between spindle and ciliary functions mechanistically separate"]},{"year":2015,"claim":"Resolved how microtubule anchoring impacts centriole biogenesis, showing it is required for proper centriole assembly and constrains satellite positioning.","evidence":"siRNA knockdown with superresolution and electron microscopy, Plk4 overexpression epistasis, and hydroxyurea arrest","pmids":["25833712"],"confidence":"High","gaps":["Mechanism coupling anchoring to centriole structural integrity unknown","Single lab"]},{"year":2015,"claim":"Placed SSX2IP in a hierarchy by identifying Wdr8 as an upstream partner required for SSX2IP recruitment to the mitotic centrosome.","evidence":"Mass spectrometry, co-IP, sequential siRNA knockdown epistasis, and superresolution microscopy","pmids":["26545777"],"confidence":"Medium","gaps":["Direct interaction interface not mapped","Single lab","Whether Wdr8 acts in ciliary as well as spindle context untested"]},{"year":2021,"claim":"Identified a developmental role beyond the centrosome, linking SSX2IP to the LIM adaptor Wtip in neural tube closure.","evidence":"Targeted proximity biotinylation, co-expression aggregation assay, and double morpholino knockdown in Xenopus embryos","pmids":["34710136"],"confidence":"Medium","gaps":["Direct biochemical interaction not deeply characterized","Mechanism connecting Wtip to junction remodeling unclear","Single lab"]},{"year":2024,"claim":"Defined a pro-tumorigenic axis in which SSX2IP engages and positively regulates FANCI to drive proliferation and migration.","evidence":"Co-IP, siRNA knockdown, FANCI overexpression rescue, proliferation/migration assays, and xenograft in breast cancer cells","pmids":["39533770"],"confidence":"Medium","gaps":["Interaction not biochemically characterized in depth","Mechanism of FANCI expression regulation unknown","Single lab"]},{"year":2026,"claim":"Established a chemoresistance function, showing miR-625-3p-regulated SSX2IP mediates extracellular-vesicle export of cisplatin.","evidence":"Luciferase reporter assay, mass spectrometry, high-speed confocal microscopy, cell death ELISA, and in vitro/in vivo assays in ovarian cancer cells","pmids":["41827805"],"confidence":"Medium","gaps":["Molecular mechanism of EV-based cisplatin loading undefined","Link between centrosomal function and EV export unexplored","Single lab"]},{"year":null,"claim":"How SSX2IP's core centrosomal/ciliary anchoring activity mechanistically relates to its disparate nuclear, developmental, and cancer functions remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of γ-TuRC or microtubule binding","Unclear whether SSX2, Wtip, FANCI, and EV-export functions share a common molecular activity","Direct versus scaffold-mediated nature of most interactions undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[1,3,4]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[2,5]}],"localization":[{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[1,4,5]},{"term_id":"GO:0005929","term_label":"cilium","supporting_discovery_ids":[2,3]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[1,4]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[1,4]},{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[2,4]}],"complexes":["centriolar satellite","γ-tubulin ring complex (γ-TuRC)"],"partners":["SSX2","PCM-1","WDR8","CEP290","WTIP","FANCI"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9Y2D8","full_name":"Afadin- and alpha-actinin-binding protein","aliases":["Afadin DIL domain-interacting protein","SSX2-interacting protein"],"length_aa":614,"mass_kda":71.2,"function":"Belongs to an adhesion system, which plays a role in the organization of homotypic, interneuronal and heterotypic cell-cell adherens junctions (AJs). May connect the nectin-afadin and E-cadherin-catenin system through alpha-actinin and may be involved in organization of the actin cytoskeleton at AJs through afadin and alpha-actinin (By similarity). Involved in cell movement: localizes at the leading edge of moving cells in response to PDGF and is required for the formation of the leading edge and the promotion of cell movement, possibly via activation of Rac signaling (By similarity). Acts as a centrosome maturation factor, probably by maintaining the integrity of the pericentriolar material and proper microtubule nucleation at mitotic spindle poles. The function seems to implicate at least in part WRAP73; the SSX2IP:WRAP73 complex is proposed to act as regulator of spindle anchoring at the mitotic centrosome (PubMed:23816619, PubMed:26545777). Involved in ciliogenesis (PubMed:24356449). It is required for targeted recruitment of the BBSome, CEP290, RAB8, and SSTR3 to the cilia (PubMed:24356449)","subcellular_location":"Cell junction, adherens junction; Nucleus; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome, centriolar satellite; Cytoplasm, cytoskeleton, cilium basal body","url":"https://www.uniprot.org/uniprotkb/Q9Y2D8/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/SSX2IP","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"TUBB4B","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/SSX2IP","total_profiled":1310},"omim":[{"mim_id":"608690","title":"SSX2-INTERACTING PROTEIN; SSX2IP","url":"https://www.omim.org/entry/608690"},{"mim_id":"608686","title":"RAB3A-INTERACTING PROTEIN; RAB3IP","url":"https://www.omim.org/entry/608686"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Centriolar satellite","reliability":"Supported"},{"location":"Centrosome","reliability":"Supported"},{"location":"Basal body","reliability":"Supported"},{"location":"Acrosome","reliability":"Additional"},{"location":"Equatorial segment","reliability":"Additional"},{"location":"Principal piece","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"retina","ntpm":109.9},{"tissue":"testis","ntpm":98.7}],"url":"https://www.proteinatlas.org/search/SSX2IP"},"hgnc":{"alias_symbol":["hMsd1"],"prev_symbol":[]},"alphafold":{"accession":"Q9Y2D8","domains":[{"cath_id":"1.20.5","chopping":"96-175","consensus_level":"high","plddt":95.5056,"start":96,"end":175}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9Y2D8","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9Y2D8-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9Y2D8-F1-predicted_aligned_error_v6.png","plddt_mean":68.62},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=SSX2IP","jax_strain_url":"https://www.jax.org/strain/search?query=SSX2IP"},"sequence":{"accession":"Q9Y2D8","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9Y2D8.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9Y2D8/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9Y2D8"}},"corpus_meta":[{"pmid":"23826132","id":"PMC_23826132","title":"Epigenetic silencing of miR-338-3p contributes to tumorigenicity in gastric cancer by targeting SSX2IP.","date":"2013","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/23826132","citation_count":63,"is_preprint":false},{"pmid":"23816619","id":"PMC_23816619","title":"The centriolar satellite protein SSX2IP promotes centrosome maturation.","date":"2013","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/23816619","citation_count":60,"is_preprint":false},{"pmid":"24356449","id":"PMC_24356449","title":"The novel centriolar satellite protein SSX2IP targets Cep290 to the ciliary transition zone.","date":"2013","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/24356449","citation_count":55,"is_preprint":false},{"pmid":"12007189","id":"PMC_12007189","title":"The cancer-related protein SSX2 interacts with the human homologue of a Ras-like GTPase interactor, RAB3IP, and a novel nuclear protein, SSX2IP.","date":"2002","source":"Genes, chromosomes & cancer","url":"https://pubmed.ncbi.nlm.nih.gov/12007189","citation_count":54,"is_preprint":false},{"pmid":"24397932","id":"PMC_24397932","title":"Msd1/SSX2IP-dependent microtubule anchorage ensures spindle orientation and primary cilia formation.","date":"2014","source":"EMBO reports","url":"https://pubmed.ncbi.nlm.nih.gov/24397932","citation_count":38,"is_preprint":false},{"pmid":"25833712","id":"PMC_25833712","title":"Centriolar satellite- and hMsd1/SSX2IP-dependent microtubule anchoring is critical for centriole assembly.","date":"2015","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/25833712","citation_count":26,"is_preprint":false},{"pmid":"23452395","id":"PMC_23452395","title":"SSX2IP promotes metastasis and chemotherapeutic resistance of hepatocellular carcinoma.","date":"2013","source":"Journal of translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/23452395","citation_count":25,"is_preprint":false},{"pmid":"26545777","id":"PMC_26545777","title":"The conserved Wdr8-hMsd1/SSX2IP complex localises to the centrosome and ensures proper spindle length and orientation.","date":"2015","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/26545777","citation_count":17,"is_preprint":false},{"pmid":"17904521","id":"PMC_17904521","title":"SSX2IP: an emerging role in cancer.","date":"2007","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/17904521","citation_count":15,"is_preprint":false},{"pmid":"34710136","id":"PMC_34710136","title":"Identification of the centrosomal maturation factor SSX2IP as a Wtip-binding partner by targeted proximity biotinylation.","date":"2021","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/34710136","citation_count":12,"is_preprint":false},{"pmid":"35658330","id":"PMC_35658330","title":"MiRNA-181b-5p Modulates Cell Proliferation, Cell Cycle, and Apoptosis by Targeting SSX2IP in Acute Lymphoblastic Leukemia.","date":"2022","source":"Turkish journal of haematology : official journal of Turkish Society of Haematology","url":"https://pubmed.ncbi.nlm.nih.gov/35658330","citation_count":9,"is_preprint":false},{"pmid":"39533770","id":"PMC_39533770","title":"SSX2IP promotes cell proliferation and migration in breast cancer by regulating FANCI.","date":"2024","source":"Cell biology international","url":"https://pubmed.ncbi.nlm.nih.gov/39533770","citation_count":0,"is_preprint":false},{"pmid":"41827805","id":"PMC_41827805","title":"MicroRNA-625-3p Increases Chemosensitivity in Ovarian Cancer Cells Through Decreasing SSX2IP-Mediated Cisplatin Export in Extracellular Vesicles.","date":"2026","source":"Cancers","url":"https://pubmed.ncbi.nlm.nih.gov/41827805","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8349,"output_tokens":2629,"usd":0.032241,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9925,"output_tokens":3250,"usd":0.065437,"stage2_stop_reason":"end_turn"},"total_usd":0.097678,"stage1_batch_id":"msgbatch_013LWZZT6MWaqB9qyTSeQBmU","stage2_batch_id":"msgbatch_0194ZzQaTGNpruoNJBbEMbt3","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2002,\n      \"finding\": \"SSX2IP was identified as a direct binding partner of SSX2 via yeast two-hybrid screening, and the interaction was confirmed by GST pull-down assay in vitro. SSX2IP interacts with the N-terminal moiety of SSX2. SSX2IP colocalizes with SSX2 in the nucleus of transfected cells.\",\n      \"method\": \"Yeast two-hybrid, GST pull-down assay, immunofluorescence of transfected cells\",\n      \"journal\": \"Genes, chromosomes & cancer\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — in vitro GST pull-down confirmed yeast two-hybrid interaction, two orthogonal methods, single lab\",\n      \"pmids\": [\"12007189\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"SSX2IP accumulates at spindle poles in a Dynein-dependent manner in Xenopus egg extracts, interacts with the γ-tubulin ring complex (γ-TuRC) and centriolar satellite protein PCM-1. Immunodepletion of SSX2IP impedes γ-TuRC loading onto centrosomes, leading to reduced microtubule nucleation and spindle assembly failure. In medaka blastomeres and somatic cells, SSX2IP knockdown causes fragmentation of pericentriolar material and chromosome segregation errors, establishing SSX2IP as a centrosome maturation and maintenance factor.\",\n      \"method\": \"Quantitative proteomics, immunodepletion in Xenopus egg extracts, co-immunoprecipitation, morpholino knockdown in medaka embryos, siRNA knockdown in somatic cells\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal co-IP, immunodepletion with functional rescue, multiple model systems (Xenopus, medaka, somatic cells), multiple orthogonal methods\",\n      \"pmids\": [\"23816619\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"SSX2IP localizes to the basal body of primary cilia in human and murine ciliated cells. siRNA knockdown of SSX2IP in human cells reduces recruitment of Cep290 to both centriolar satellites and the basal body, drastically reduces entry of the BBSome and Rab8 accumulation at the ciliary base, limits targeting of the ciliary membrane protein somatostatin receptor 3, and significantly reduces axoneme length. SSX2IP is thus a targeting factor for ciliary membrane proteins that cooperates with Cep290, the BBSome, and Rab8.\",\n      \"method\": \"siRNA knockdown, immunofluorescence, localization studies in human and murine ciliated cells\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean siRNA KD with multiple specific downstream readouts (Cep290, BBSome, Rab8, somatostatin receptor 3), replicated across human and murine systems\",\n      \"pmids\": [\"24356449\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"hMsd1/SSX2IP is delivered to the centrosome in a centriolar satellite-dependent manner and binds the γ-tubulin complex. Depletion of hMsd1/SSX2IP leads to disorganized interphase microtubules and misoriented mitotic spindles with reduced length, establishing SSX2IP as a microtubule-anchoring protein. Knockdown of the zebrafish orthologue causes ciliary defects and disturbed left-right asymmetry, confirming a conserved role in ciliogenesis.\",\n      \"method\": \"siRNA knockdown, co-immunoprecipitation, immunofluorescence, zebrafish morpholino knockdown\",\n      \"journal\": \"EMBO reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — co-IP for γ-tubulin binding, siRNA depletion phenotype replicated in zebrafish morpholino model, multiple orthogonal readouts\",\n      \"pmids\": [\"24397932\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"hMsd1/SSX2IP-mediated microtubule anchoring to the centrosome is essential for proper centriole assembly and duplication. Upon hMsd1/SSX2IP knockdown, centriolar satellites become stuck at the microtubule minus end near the centrosome and accumulate centrosomal proteins ectopically. Microtubule structures (even when not properly anchored) are still required for satellite aggregation. Superresolution and electron microscopy revealed faulty centriole structures under these conditions. SSX2IP-depleted cells are insensitive to Plk4 overproduction-induced ectopic centriole formation but accelerate centrosome reduplication upon hydroxyurea arrest.\",\n      \"method\": \"siRNA knockdown, superresolution microscopy, electron microscopy, Plk4 overexpression epistasis, hydroxyurea arrest\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — multiple orthogonal methods including electron microscopy and superresolution, genetic epistasis with Plk4, single lab but thorough experimental design\",\n      \"pmids\": [\"25833712\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Wdr8 constitutively localizes to the proximal end of the mother centriole and forms a complex with hMsd1/SSX2IP identified by mass spectrometry. Wdr8 depletion reduces recruitment of hMsd1/SSX2IP to the mitotic centrosome (but not vice versa), and knockdown of either protein produces similar spindle defects (shortened and misoriented spindle microtubules), placing Wdr8 upstream of hMsd1/SSX2IP in centrosome function.\",\n      \"method\": \"Mass spectrometry, co-immunoprecipitation, siRNA knockdown, superresolution microscopy, immunofluorescence\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP confirmed by MS, epistasis by sequential knockdown, single lab\",\n      \"pmids\": [\"26545777\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Targeted proximity biotinylation identified SSX2IP as a binding partner of the N-terminal domain of Wtip (a LIM-domain adaptor). Physical association was confirmed and the two proteins formed mixed aggregates upon overexpression. Double depletion of Wtip and SSX2IP in Xenopus embryos disrupted neural tube closure, indicating a functional interaction during neurulation and cell junction remodeling.\",\n      \"method\": \"Targeted proximity biotinylation (BirA-anti-GFP), co-expression aggregation assay, double morpholino knockdown in Xenopus embryos\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — proximity biotinylation plus co-expression validation plus in vivo double-KD epistasis, single lab, limited biochemical depth\",\n      \"pmids\": [\"34710136\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"SSX2IP physically interacts with FANCI (FA Complementation Group I) as confirmed by co-immunoprecipitation. SSX2IP positively regulates FANCI expression, and FANCI overexpression partially rescues the anti-proliferative and anti-migratory effects of SSX2IP knockdown in breast cancer cells, placing SSX2IP upstream of FANCI in a pro-tumorigenic pathway.\",\n      \"method\": \"Co-immunoprecipitation, siRNA knockdown, overexpression rescue, functional proliferation/migration assays, xenograft\",\n      \"journal\": \"Cell biology international\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — co-IP plus rescue epistasis, single lab, no deep biochemical characterization of the interaction\",\n      \"pmids\": [\"39533770\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"SSX2IP was confirmed as a direct transcriptional/functional target of miR-625-3p by reporter assays, and its upregulation promotes cisplatin export via extracellular vesicles in ovarian cancer cells, thereby enhancing cisplatin resistance. Mass spectrometry and high-speed confocal microscopy supported SSX2IP's role in mediating EV-based cisplatin secretion.\",\n      \"method\": \"Luciferase reporter assay, mass spectrometry, high-speed confocal microscopy, cell death ELISA, in vitro and in vivo functional assays\",\n      \"journal\": \"Cancers\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — reporter assay plus MS plus confocal imaging, single lab, functional consequence defined\",\n      \"pmids\": [\"41827805\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"SSX2IP (hMsd1) is a centriolar satellite protein that is delivered to the centrosome in a centriolar satellite-dependent manner where it binds the γ-tubulin ring complex to anchor microtubules, promotes centrosome maturation and centriole assembly, is required for proper mitotic spindle orientation and length (functioning downstream of the centrosomal protein Wdr8), and acts as a targeting factor for ciliary membrane proteins by recruiting Cep290 to the basal body and facilitating BBSome/Rab8-dependent cargo delivery to primary cilia; additionally, SSX2IP directly interacts with SSX2 via its N-terminus, associates with the LIM-domain adaptor Wtip during neural tube closure, and in cancer contexts physically engages FANCI to promote proliferation and migration and mediates extracellular vesicle export of cisplatin to confer drug resistance.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"SSX2IP (hMsd1) is a centriolar satellite protein that governs centrosome maturation, microtubule anchoring, and ciliogenesis [#1, #4]. Delivered to the centrosome in a centriolar satellite-dependent manner, it accumulates at spindle poles via Dynein and binds the γ-tubulin ring complex (γ-TuRC) together with the satellite protein PCM-1, and its loss prevents γ-TuRC loading onto centrosomes, reducing microtubule nucleation and causing spindle assembly failure, pericentriolar material fragmentation, and chromosome segregation errors [#1]. By anchoring microtubule minus ends at the centrosome it organizes interphase microtubules, sets mitotic spindle length and orientation, and is required for proper centriole assembly and duplication, with its depletion trapping satellites near the centrosome and producing faulty centriole structures [#4]. SSX2IP functions downstream of Wdr8, which localizes to the proximal mother centriole and is required to recruit SSX2IP to the mitotic centrosome [#5]. At the basal body, SSX2IP acts as a targeting factor for ciliary membrane proteins, recruiting Cep290 and enabling BBSome entry, Rab8 accumulation, somatostatin receptor 3 delivery, and axoneme elongation, and its orthologs are required for ciliogenesis and left-right asymmetry [#2, #3]. Originally identified as a nuclear binding partner of the cancer-testis antigen SSX2 through its N-terminus [#0], SSX2IP also associates with the LIM-domain adaptor Wtip during Xenopus neural tube closure [#6], and in cancer it engages FANCI to promote proliferation and migration [#7] and mediates extracellular-vesicle export of cisplatin to confer drug resistance [#8].\",\n  \"teleology\": [\n    {\n      \"year\": 2002,\n      \"claim\": \"Established the first molecular partner of SSX2IP, defining it as an SSX2-interacting nuclear protein and naming the gene.\",\n      \"evidence\": \"Yeast two-hybrid screen with GST pull-down confirmation and immunofluorescence of transfected cells\",\n      \"pmids\": [\"12007189\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of the SSX2 interaction undefined\", \"No endogenous validation beyond transfected cells\", \"Binding region on SSX2IP not mapped\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Answered what SSX2IP does at the centrosome by showing it binds the γ-TuRC and is required for its loading, establishing SSX2IP as a centrosome maturation factor.\",\n      \"evidence\": \"Quantitative proteomics, immunodepletion in Xenopus egg extracts, reciprocal co-IP, and morpholino/siRNA knockdown across medaka and somatic cells\",\n      \"pmids\": [\"23816619\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct versus indirect γ-TuRC binding not resolved\", \"How Dynein-dependent pole accumulation is regulated unclear\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Extended SSX2IP function to the cilium, defining it as a basal-body targeting factor that recruits Cep290 and enables BBSome/Rab8-dependent ciliary cargo delivery.\",\n      \"evidence\": \"siRNA knockdown with immunofluorescent readouts of Cep290, BBSome, Rab8, and somatostatin receptor 3 in human and murine ciliated cells\",\n      \"pmids\": [\"24356449\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct binding partner among Cep290/BBSome not biochemically mapped\", \"Mechanism linking satellite delivery to basal-body targeting unresolved\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Connected the centrosomal and ciliary roles by showing satellite-dependent delivery and γ-tubulin binding anchor microtubules, controlling spindle orientation and conserved ciliogenesis.\",\n      \"evidence\": \"siRNA depletion, co-IP for γ-tubulin, and zebrafish morpholino knockdown with left-right asymmetry readouts\",\n      \"pmids\": [\"24397932\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular basis of microtubule anchoring not structurally defined\", \"Link between spindle and ciliary functions mechanistically separate\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Resolved how microtubule anchoring impacts centriole biogenesis, showing it is required for proper centriole assembly and constrains satellite positioning.\",\n      \"evidence\": \"siRNA knockdown with superresolution and electron microscopy, Plk4 overexpression epistasis, and hydroxyurea arrest\",\n      \"pmids\": [\"25833712\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism coupling anchoring to centriole structural integrity unknown\", \"Single lab\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Placed SSX2IP in a hierarchy by identifying Wdr8 as an upstream partner required for SSX2IP recruitment to the mitotic centrosome.\",\n      \"evidence\": \"Mass spectrometry, co-IP, sequential siRNA knockdown epistasis, and superresolution microscopy\",\n      \"pmids\": [\"26545777\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct interaction interface not mapped\", \"Single lab\", \"Whether Wdr8 acts in ciliary as well as spindle context untested\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identified a developmental role beyond the centrosome, linking SSX2IP to the LIM adaptor Wtip in neural tube closure.\",\n      \"evidence\": \"Targeted proximity biotinylation, co-expression aggregation assay, and double morpholino knockdown in Xenopus embryos\",\n      \"pmids\": [\"34710136\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct biochemical interaction not deeply characterized\", \"Mechanism connecting Wtip to junction remodeling unclear\", \"Single lab\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Defined a pro-tumorigenic axis in which SSX2IP engages and positively regulates FANCI to drive proliferation and migration.\",\n      \"evidence\": \"Co-IP, siRNA knockdown, FANCI overexpression rescue, proliferation/migration assays, and xenograft in breast cancer cells\",\n      \"pmids\": [\"39533770\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Interaction not biochemically characterized in depth\", \"Mechanism of FANCI expression regulation unknown\", \"Single lab\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Established a chemoresistance function, showing miR-625-3p-regulated SSX2IP mediates extracellular-vesicle export of cisplatin.\",\n      \"evidence\": \"Luciferase reporter assay, mass spectrometry, high-speed confocal microscopy, cell death ELISA, and in vitro/in vivo assays in ovarian cancer cells\",\n      \"pmids\": [\"41827805\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular mechanism of EV-based cisplatin loading undefined\", \"Link between centrosomal function and EV export unexplored\", \"Single lab\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How SSX2IP's core centrosomal/ciliary anchoring activity mechanistically relates to its disparate nuclear, developmental, and cancer functions remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of γ-TuRC or microtubule binding\", \"Unclear whether SSX2, Wtip, FANCI, and EV-export functions share a common molecular activity\", \"Direct versus scaffold-mediated nature of most interactions undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [1, 3, 4]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [2, 5]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [1, 4, 5]},\n      {\"term_id\": \"GO:0005929\", \"supporting_discovery_ids\": [2, 3]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [1, 4]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [1, 4]},\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [2, 4]}\n    ],\n    \"complexes\": [\"centriolar satellite\", \"γ-tubulin ring complex (γ-TuRC)\"],\n    \"partners\": [\"SSX2\", \"PCM-1\", \"Wdr8\", \"Cep290\", \"Wtip\", \"FANCI\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}