{"gene":"CEP162","run_date":"2026-04-28T17:28:52","timeline":{"discoveries":[{"year":2013,"finding":"CEP162 (KIAA1009) is an axoneme-recognition protein pre-tethered at centriole distal ends that promotes and restricts transition zone assembly specifically at the cilia base. It interacts with core transition zone components and mediates their association with microtubules. Loss of CEP162 arrests ciliogenesis at the transition zone assembly stage. Abolishing its centriolar tethering allows CEP162 to stay on the growing axoneme end and ectopically assemble transition zone components at cilia tips, generating extra-long cilia with swollen tips that release ciliary contents extracellularly.","method":"Quantitative centrosome proteomics, Co-IP, loss-of-function (siRNA/KD), tethering mutants, live imaging, fractionation","journal":"Nature cell biology","confidence":"High","confidence_rationale":"Tier 1–2 — multiple orthogonal methods (proteomics, Co-IP, KO phenotype, mutant rescue, imaging) in a single rigorous study","pmids":["23644468"],"is_preprint":false},{"year":2006,"finding":"QN1/KIAA1009 (CEP162) is an ATPase localized at spindle poles and centrosomes during mitosis. siRNA-mediated depletion leads to chromosome segregation defects and abnormal centrosome separation, causing cell death, identifying it as a microtubule-associated ATPase required for cell division.","method":"siRNA knockdown, immunofluorescence localization, cell viability assays, sequence conservation analysis","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2–3 — KD with defined cellular phenotype and direct localization, single lab","pmids":["16302001"],"is_preprint":false},{"year":2001,"finding":"CEP162 (KIAA1009/QN1) protein redistributes from the cytoplasm in proliferating cells to predominantly nuclear localization in post-mitotic neurons during differentiation. Antisense-mediated reduction of QN1 protein causes additional mitosis and retinal dysplasia in vivo, indicating a key role at the onset of neuronal cell cycle withdrawal.","method":"Antisense oligonucleotide knockdown in vitro and in vivo, immunofluorescence subcellular localization, retinal developmental assays","journal":"Mechanisms of development","confidence":"Medium","confidence_rationale":"Tier 2–3 — loss-of-function with defined phenotype and localization data, single lab","pmids":["11287185"],"is_preprint":false},{"year":2001,"finding":"KIAA1009 (CEP162) was identified as a nuclear protein co-localizing with GAS41 and NuMA in glioma cells, identified as a binding partner of GAS41 by yeast two-hybrid screening.","method":"Yeast two-hybrid screening, immunofluorescence co-localization, polyclonal antibody generation and Western blot","journal":"Oncogene","confidence":"Low","confidence_rationale":"Tier 3 — yeast two-hybrid and co-localization only, no reciprocal Co-IP confirmation","pmids":["11521196"],"is_preprint":false},{"year":2023,"finding":"A truncating variant in CEP162 (CEP162-E646R*5) causes late-onset retinitis pigmentosa. The mutant protein localizes normally to the mitotic spindle but is absent from the basal body in primary and photoreceptor cilia, impairing transition zone component recruitment and causing delayed dysmorphic cilia formation. In contrast, shRNA knockdown of Cep162 in developing mouse retina increased cell death rescued by the CEP162-E646R*5 mutant, demonstrating that CEP162 has separable ciliary and neurogenic functions.","method":"Patient variant analysis, shRNA knockdown in mouse retina, immunolocalization, rescue experiments with mutant construct","journal":"The Journal of clinical investigation","confidence":"High","confidence_rationale":"Tier 1–2 — multiple orthogonal methods (patient genetics, KD, rescue, localization) demonstrating separable functions","pmids":["36862503"],"is_preprint":false},{"year":2024,"finding":"In Drosophila, the Cep131-Cep162 module near the axoneme cooperates with the Cby-Fam92 module near the ciliary membrane to synergistically maintain Cep290 at the basal body and initiate ciliogenesis. Concurrent deletion of components from both modules causes complete loss of Cep290 from the basal body and blocks ciliogenesis initiation.","method":"Drosophila genetic deletion, epistasis analysis, immunolocalization","journal":"PLoS biology","confidence":"Medium","confidence_rationale":"Tier 2 — genetic epistasis in Drosophila ortholog with defined molecular pathway placement","pmids":["38442096"],"is_preprint":false},{"year":2025,"finding":"C2CD3 depletion destabilizes CEP162 at the distal microtubule tip of the centriole, placing CEP162 downstream of C2CD3 in distal centriole organization. CEP162 is identified as a distal microtubule tip protein whose localization depends on the C2CD3-organized luminal ring network.","method":"Ultrastructure expansion microscopy (U-ExM), cryo-electron tomography, C2CD3 depletion with immunolocalization readout","journal":"PLoS biology","confidence":"Medium","confidence_rationale":"Tier 2 — structural and functional imaging with genetic depletion, single study","pmids":["41364719"],"is_preprint":false},{"year":2026,"finding":"Chronic hypoxia downregulates ASXL2, reducing EZH2 binding to the CEP162 promoter (at bp 3482–3511), decreasing H3K27me3 modification and increasing CEP162 transcription. Overexpressed CEP162 competes with TUBA3A for TUBB3 binding, depleting ciliary TUBB3 and destabilizing axonemal microtubules, causing sperm malformations.","method":"ChIP assay, promoter binding analysis, overexpression competition assay (CEP162 vs. TUBA3A for TUBB3), spermatogenesis phenotype analysis","journal":"Advanced science","confidence":"Medium","confidence_rationale":"Tier 2 — ChIP, binding competition assay, and defined phenotypic readout in single study","pmids":["41782374"],"is_preprint":false}],"current_model":"CEP162 is a centrosomal/axoneme-associated ATPase pre-tethered at centriole distal ends that recognizes axonemal microtubules to promote and spatially restrict transition zone assembly at the cilia base by interacting with core transition zone components (including CEP131 and CEP290); it also supports mitotic spindle integrity at centrosomes and retinal neurogenesis, with its ciliary and neurogenic functions being molecularly separable, and its expression epigenetically regulated via the ASXL2-EZH2-H3K27me3 axis."},"narrative":{"teleology":[{"year":2001,"claim":"Establishing that CEP162 participates in neuronal differentiation answered whether this uncharacterized protein has developmental roles: it redistributes to the nucleus in post-mitotic neurons, and its reduction causes ectopic mitosis and retinal dysplasia.","evidence":"Antisense knockdown in chick retina with immunolocalization","pmids":["11287185"],"confidence":"Medium","gaps":["Molecular targets mediating the neurogenic function were not identified","Whether the nuclear relocalization is essential for cell-cycle exit was not tested"]},{"year":2006,"claim":"Demonstrating that CEP162 is an ATPase at mitotic spindle poles whose depletion causes chromosome segregation defects established a centrosome-associated mitotic function distinct from its later-discovered ciliary role.","evidence":"siRNA knockdown in human cells with spindle pole immunolocalization and viability assays","pmids":["16302001"],"confidence":"Medium","gaps":["ATPase activity was inferred from sequence but not biochemically measured","Whether mitotic and ciliary functions share the same protein domains was unknown"]},{"year":2013,"claim":"A landmark study resolved how transition zone assembly is spatially restricted: CEP162 is pre-tethered at centriole distal ends, recognizes axonemal microtubules, and recruits transition zone components; untethering it causes ectopic transition zone assembly at cilia tips, establishing CEP162 as the spatial gatekeeper of transition zone positioning.","evidence":"Quantitative centrosome proteomics, Co-IP, siRNA knockdown, tethering-deficient mutants, and live imaging in mammalian cells","pmids":["23644468"],"confidence":"High","gaps":["The identity of the tethering anchor at the centriole distal end was not determined","Direct binding partners among transition zone components were not fully mapped"]},{"year":2023,"claim":"Identification of a disease-causing CEP162 truncation that selectively disrupts basal-body but not spindle localization proved that CEP162's ciliary and neurogenic functions are molecularly separable and linked CEP162 to retinitis pigmentosa.","evidence":"Patient variant analysis, shRNA knockdown in mouse retina, rescue experiments with mutant and wild-type constructs","pmids":["36862503"],"confidence":"High","gaps":["The protein domain mediating basal-body targeting specifically was not delineated","Whether other ciliopathy phenotypes beyond retinal degeneration arise from CEP162 variants is unexplored"]},{"year":2024,"claim":"Genetic epistasis in Drosophila placed CEP162 in a Cep131-Cep162 axonemal module that cooperates with a membrane-proximal Cby-Fam92 module to maintain Cep290 at the basal body, defining a two-module architecture for ciliogenesis initiation.","evidence":"Drosophila combinatorial genetic deletions with Cep290 immunolocalization","pmids":["38442096"],"confidence":"Medium","gaps":["Direct physical interaction between Cep131 and Cep162 was not biochemically demonstrated in this system","Whether the two-module architecture is conserved in mammalian ciliogenesis is untested"]},{"year":2025,"claim":"Identifying C2CD3 as an upstream determinant of CEP162 distal-tip localization resolved how CEP162 is tethered: a C2CD3-organized luminal ring network stabilizes CEP162 at the distal microtubule tip.","evidence":"Ultrastructure expansion microscopy and cryo-ET with C2CD3 depletion in human cells","pmids":["41364719"],"confidence":"Medium","gaps":["Whether C2CD3 and CEP162 interact directly or through intermediate adaptor proteins is unresolved","Structural basis of CEP162 recognition of microtubule distal tips is unknown"]},{"year":2026,"claim":"Discovery that CEP162 expression is epigenetically controlled by the ASXL2-EZH2-H3K27me3 axis, and that overexpressed CEP162 competes with TUBA3A for TUBB3 binding to destabilize axonemal microtubules, revealed a tubulin-competition mechanism linking CEP162 dosage to cilia structural integrity.","evidence":"ChIP assay on CEP162 promoter, binding competition assay for TUBB3, spermatogenesis phenotype under chronic hypoxia","pmids":["41782374"],"confidence":"Medium","gaps":["Whether CEP162-TUBB3 binding is direct and stoichiometric has not been confirmed with purified proteins","Relevance of this epigenetic regulation outside the spermatogenesis context is unknown"]},{"year":null,"claim":"Key unresolved questions include the structural basis of CEP162's axoneme-recognition and transition-zone-recruiting activities, whether its ATPase activity is catalytically required for any of its functions, and the full spectrum of human disease caused by CEP162 variants.","evidence":"","pmids":[],"confidence":"High","gaps":["No crystal or cryo-EM structure of CEP162 exists","ATPase activity has not been biochemically reconstituted or shown to be required","Complete interactome mapping of CEP162 at the transition zone is lacking"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140657","term_label":"ATP-dependent activity","supporting_discovery_ids":[1]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[0,1,6,7]}],"localization":[{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[0,1,4,6]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[0,1]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[2]},{"term_id":"GO:0005929","term_label":"cilium","supporting_discovery_ids":[0,4,5]}],"pathway":[{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[0,4,5,6]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[1]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[2,4]}],"complexes":[],"partners":["CEP290","CEP131","C2CD3","TUBB3"],"other_free_text":[]},"mechanistic_narrative":"CEP162 is a microtubule-associated ATPase that functions at centriole distal ends to coordinate transition zone assembly during ciliogenesis and to support mitotic spindle integrity. Pre-tethered at the distal tips of centriolar microtubules in a C2CD3-dependent manner, CEP162 recognizes axonemal microtubules and recruits core transition zone components including CEP290; loss of CEP162 arrests ciliogenesis at the transition zone assembly stage, while untethering it causes ectopic transition zone assembly at cilia tips [PMID:23644468, PMID:41364719, PMID:38442096]. CEP162 also localizes to spindle poles during mitosis, where its depletion causes chromosome segregation defects and abnormal centrosome separation, and it promotes retinal neurogenesis through a function molecularly separable from its ciliary role [PMID:16302001, PMID:36862503]. A truncating CEP162 variant causes late-onset retinitis pigmentosa by selectively abolishing basal-body localization and ciliary transition zone recruitment while preserving spindle and neurogenic functions [PMID:36862503]."},"prefetch_data":{"uniprot":{"accession":"Q5TB80","full_name":"Centrosomal protein of 162 kDa","aliases":["Protein QN1 homolog"],"length_aa":1403,"mass_kda":161.9,"function":"Required to promote assembly of the transition zone in primary cilia. Acts by specifically recognizing and binding the axonemal microtubule. Localizes to the distal ends of centrioles before ciliogenesis and directly binds to axonemal microtubule, thereby promoting and restricting transition zone formation specifically at the cilia base. Required to mediate CEP290 association with microtubules","subcellular_location":"Cytoplasm, cytoskeleton, microtubule organizing center, centrosome, centriole; Cytoplasm, cytoskeleton, spindle; Nucleus","url":"https://www.uniprot.org/uniprotkb/Q5TB80/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CEP162","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":"MIF","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/CEP162","total_profiled":1310},"omim":[{"mim_id":"610201","title":"CENTROSOMAL PROTEIN, 162-KD; CEP162","url":"https://www.omim.org/entry/610201"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nucleoplasm","reliability":"Approved"},{"location":"Cytosol","reliability":"Approved"},{"location":"Centriolar satellite","reliability":"Additional"},{"location":"Basal body","reliability":"Additional"},{"location":"Connecting piece","reliability":"Additional"},{"location":"Mid piece","reliability":"Additional"},{"location":"Principal piece","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/CEP162"},"hgnc":{"alias_symbol":["QN1"],"prev_symbol":["C6orf84","KIAA1009"]},"alphafold":{"accession":"Q5TB80","domains":[{"cath_id":"-","chopping":"1030-1116","consensus_level":"medium","plddt":82.9999,"start":1030,"end":1116},{"cath_id":"1.20.5","chopping":"1170-1241","consensus_level":"medium","plddt":86.0592,"start":1170,"end":1241},{"cath_id":"1.20.5","chopping":"1244-1305","consensus_level":"medium","plddt":86.8853,"start":1244,"end":1305},{"cath_id":"1.20.5","chopping":"1326-1386","consensus_level":"medium","plddt":91.8567,"start":1326,"end":1386}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5TB80","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q5TB80-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q5TB80-F1-predicted_aligned_error_v6.png","plddt_mean":62.94},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CEP162","jax_strain_url":"https://www.jax.org/strain/search?query=CEP162"},"sequence":{"accession":"Q5TB80","fasta_url":"https://rest.uniprot.org/uniprotkb/Q5TB80.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q5TB80/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5TB80"}},"corpus_meta":[{"pmid":"31584090","id":"PMC_31584090","title":"New substituted quinoxalines inhibit triple-negative breast cancer by specifically downregulating the c-MYC transcription.","date":"2019","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/31584090","citation_count":85,"is_preprint":false},{"pmid":"23644468","id":"PMC_23644468","title":"CEP162 is an axoneme-recognition protein promoting ciliary transition zone assembly at the cilia base.","date":"2013","source":"Nature cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/23644468","citation_count":79,"is_preprint":false},{"pmid":"2168975","id":"PMC_2168975","title":"A fusion-defective mutant of the vesicular stomatitis virus glycoprotein.","date":"1990","source":"Journal of virology","url":"https://pubmed.ncbi.nlm.nih.gov/2168975","citation_count":73,"is_preprint":false},{"pmid":"25364816","id":"PMC_25364816","title":"A genome-wide association study for diabetic retinopathy in a Japanese population: potential association with a long intergenic non-coding RNA.","date":"2014","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/25364816","citation_count":67,"is_preprint":false},{"pmid":"28902444","id":"PMC_28902444","title":"Genomewide association studies of suicide attempts in US soldiers.","date":"2017","source":"American journal of medical genetics. 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It interacts with core transition zone components and mediates their association with microtubules. Loss of CEP162 arrests ciliogenesis at the transition zone assembly stage. Abolishing its centriolar tethering allows CEP162 to stay on the growing axoneme end and ectopically assemble transition zone components at cilia tips, generating extra-long cilia with swollen tips that release ciliary contents extracellularly.\",\n      \"method\": \"Quantitative centrosome proteomics, Co-IP, loss-of-function (siRNA/KD), tethering mutants, live imaging, fractionation\",\n      \"journal\": \"Nature cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — multiple orthogonal methods (proteomics, Co-IP, KO phenotype, mutant rescue, imaging) in a single rigorous study\",\n      \"pmids\": [\"23644468\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"QN1/KIAA1009 (CEP162) is an ATPase localized at spindle poles and centrosomes during mitosis. siRNA-mediated depletion leads to chromosome segregation defects and abnormal centrosome separation, causing cell death, identifying it as a microtubule-associated ATPase required for cell division.\",\n      \"method\": \"siRNA knockdown, immunofluorescence localization, cell viability assays, sequence conservation analysis\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 — KD with defined cellular phenotype and direct localization, single lab\",\n      \"pmids\": [\"16302001\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"CEP162 (KIAA1009/QN1) protein redistributes from the cytoplasm in proliferating cells to predominantly nuclear localization in post-mitotic neurons during differentiation. Antisense-mediated reduction of QN1 protein causes additional mitosis and retinal dysplasia in vivo, indicating a key role at the onset of neuronal cell cycle withdrawal.\",\n      \"method\": \"Antisense oligonucleotide knockdown in vitro and in vivo, immunofluorescence subcellular localization, retinal developmental assays\",\n      \"journal\": \"Mechanisms of development\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 — loss-of-function with defined phenotype and localization data, single lab\",\n      \"pmids\": [\"11287185\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"KIAA1009 (CEP162) was identified as a nuclear protein co-localizing with GAS41 and NuMA in glioma cells, identified as a binding partner of GAS41 by yeast two-hybrid screening.\",\n      \"method\": \"Yeast two-hybrid screening, immunofluorescence co-localization, polyclonal antibody generation and Western blot\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — yeast two-hybrid and co-localization only, no reciprocal Co-IP confirmation\",\n      \"pmids\": [\"11521196\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"A truncating variant in CEP162 (CEP162-E646R*5) causes late-onset retinitis pigmentosa. The mutant protein localizes normally to the mitotic spindle but is absent from the basal body in primary and photoreceptor cilia, impairing transition zone component recruitment and causing delayed dysmorphic cilia formation. In contrast, shRNA knockdown of Cep162 in developing mouse retina increased cell death rescued by the CEP162-E646R*5 mutant, demonstrating that CEP162 has separable ciliary and neurogenic functions.\",\n      \"method\": \"Patient variant analysis, shRNA knockdown in mouse retina, immunolocalization, rescue experiments with mutant construct\",\n      \"journal\": \"The Journal of clinical investigation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — multiple orthogonal methods (patient genetics, KD, rescue, localization) demonstrating separable functions\",\n      \"pmids\": [\"36862503\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In Drosophila, the Cep131-Cep162 module near the axoneme cooperates with the Cby-Fam92 module near the ciliary membrane to synergistically maintain Cep290 at the basal body and initiate ciliogenesis. Concurrent deletion of components from both modules causes complete loss of Cep290 from the basal body and blocks ciliogenesis initiation.\",\n      \"method\": \"Drosophila genetic deletion, epistasis analysis, immunolocalization\",\n      \"journal\": \"PLoS biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genetic epistasis in Drosophila ortholog with defined molecular pathway placement\",\n      \"pmids\": [\"38442096\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"C2CD3 depletion destabilizes CEP162 at the distal microtubule tip of the centriole, placing CEP162 downstream of C2CD3 in distal centriole organization. CEP162 is identified as a distal microtubule tip protein whose localization depends on the C2CD3-organized luminal ring network.\",\n      \"method\": \"Ultrastructure expansion microscopy (U-ExM), cryo-electron tomography, C2CD3 depletion with immunolocalization readout\",\n      \"journal\": \"PLoS biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — structural and functional imaging with genetic depletion, single study\",\n      \"pmids\": [\"41364719\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Chronic hypoxia downregulates ASXL2, reducing EZH2 binding to the CEP162 promoter (at bp 3482–3511), decreasing H3K27me3 modification and increasing CEP162 transcription. Overexpressed CEP162 competes with TUBA3A for TUBB3 binding, depleting ciliary TUBB3 and destabilizing axonemal microtubules, causing sperm malformations.\",\n      \"method\": \"ChIP assay, promoter binding analysis, overexpression competition assay (CEP162 vs. TUBA3A for TUBB3), spermatogenesis phenotype analysis\",\n      \"journal\": \"Advanced science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — ChIP, binding competition assay, and defined phenotypic readout in single study\",\n      \"pmids\": [\"41782374\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CEP162 is a centrosomal/axoneme-associated ATPase pre-tethered at centriole distal ends that recognizes axonemal microtubules to promote and spatially restrict transition zone assembly at the cilia base by interacting with core transition zone components (including CEP131 and CEP290); it also supports mitotic spindle integrity at centrosomes and retinal neurogenesis, with its ciliary and neurogenic functions being molecularly separable, and its expression epigenetically regulated via the ASXL2-EZH2-H3K27me3 axis.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"CEP162 is a microtubule-associated ATPase that functions at centriole distal ends to coordinate transition zone assembly during ciliogenesis and to support mitotic spindle integrity. Pre-tethered at the distal tips of centriolar microtubules in a C2CD3-dependent manner, CEP162 recognizes axonemal microtubules and recruits core transition zone components including CEP290; loss of CEP162 arrests ciliogenesis at the transition zone assembly stage, while untethering it causes ectopic transition zone assembly at cilia tips [PMID:23644468, PMID:41364719, PMID:38442096]. CEP162 also localizes to spindle poles during mitosis, where its depletion causes chromosome segregation defects and abnormal centrosome separation, and it promotes retinal neurogenesis through a function molecularly separable from its ciliary role [PMID:16302001, PMID:36862503]. A truncating CEP162 variant causes late-onset retinitis pigmentosa by selectively abolishing basal-body localization and ciliary transition zone recruitment while preserving spindle and neurogenic functions [PMID:36862503].\",\n  \"teleology\": [\n    {\n      \"year\": 2001,\n      \"claim\": \"Establishing that CEP162 participates in neuronal differentiation answered whether this uncharacterized protein has developmental roles: it redistributes to the nucleus in post-mitotic neurons, and its reduction causes ectopic mitosis and retinal dysplasia.\",\n      \"evidence\": \"Antisense knockdown in chick retina with immunolocalization\",\n      \"pmids\": [\"11287185\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular targets mediating the neurogenic function were not identified\",\n        \"Whether the nuclear relocalization is essential for cell-cycle exit was not tested\"\n      ]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Demonstrating that CEP162 is an ATPase at mitotic spindle poles whose depletion causes chromosome segregation defects established a centrosome-associated mitotic function distinct from its later-discovered ciliary role.\",\n      \"evidence\": \"siRNA knockdown in human cells with spindle pole immunolocalization and viability assays\",\n      \"pmids\": [\"16302001\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"ATPase activity was inferred from sequence but not biochemically measured\",\n        \"Whether mitotic and ciliary functions share the same protein domains was unknown\"\n      ]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"A landmark study resolved how transition zone assembly is spatially restricted: CEP162 is pre-tethered at centriole distal ends, recognizes axonemal microtubules, and recruits transition zone components; untethering it causes ectopic transition zone assembly at cilia tips, establishing CEP162 as the spatial gatekeeper of transition zone positioning.\",\n      \"evidence\": \"Quantitative centrosome proteomics, Co-IP, siRNA knockdown, tethering-deficient mutants, and live imaging in mammalian cells\",\n      \"pmids\": [\"23644468\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The identity of the tethering anchor at the centriole distal end was not determined\",\n        \"Direct binding partners among transition zone components were not fully mapped\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Identification of a disease-causing CEP162 truncation that selectively disrupts basal-body but not spindle localization proved that CEP162's ciliary and neurogenic functions are molecularly separable and linked CEP162 to retinitis pigmentosa.\",\n      \"evidence\": \"Patient variant analysis, shRNA knockdown in mouse retina, rescue experiments with mutant and wild-type constructs\",\n      \"pmids\": [\"36862503\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The protein domain mediating basal-body targeting specifically was not delineated\",\n        \"Whether other ciliopathy phenotypes beyond retinal degeneration arise from CEP162 variants is unexplored\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Genetic epistasis in Drosophila placed CEP162 in a Cep131-Cep162 axonemal module that cooperates with a membrane-proximal Cby-Fam92 module to maintain Cep290 at the basal body, defining a two-module architecture for ciliogenesis initiation.\",\n      \"evidence\": \"Drosophila combinatorial genetic deletions with Cep290 immunolocalization\",\n      \"pmids\": [\"38442096\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct physical interaction between Cep131 and Cep162 was not biochemically demonstrated in this system\",\n        \"Whether the two-module architecture is conserved in mammalian ciliogenesis is untested\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Identifying C2CD3 as an upstream determinant of CEP162 distal-tip localization resolved how CEP162 is tethered: a C2CD3-organized luminal ring network stabilizes CEP162 at the distal microtubule tip.\",\n      \"evidence\": \"Ultrastructure expansion microscopy and cryo-ET with C2CD3 depletion in human cells\",\n      \"pmids\": [\"41364719\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether C2CD3 and CEP162 interact directly or through intermediate adaptor proteins is unresolved\",\n        \"Structural basis of CEP162 recognition of microtubule distal tips is unknown\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Discovery that CEP162 expression is epigenetically controlled by the ASXL2-EZH2-H3K27me3 axis, and that overexpressed CEP162 competes with TUBA3A for TUBB3 binding to destabilize axonemal microtubules, revealed a tubulin-competition mechanism linking CEP162 dosage to cilia structural integrity.\",\n      \"evidence\": \"ChIP assay on CEP162 promoter, binding competition assay for TUBB3, spermatogenesis phenotype under chronic hypoxia\",\n      \"pmids\": [\"41782374\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether CEP162-TUBB3 binding is direct and stoichiometric has not been confirmed with purified proteins\",\n        \"Relevance of this epigenetic regulation outside the spermatogenesis context is unknown\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Key unresolved questions include the structural basis of CEP162's axoneme-recognition and transition-zone-recruiting activities, whether its ATPase activity is catalytically required for any of its functions, and the full spectrum of human disease caused by CEP162 variants.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"No crystal or cryo-EM structure of CEP162 exists\",\n        \"ATPase activity has not been biochemically reconstituted or shown to be required\",\n        \"Complete interactome mapping of CEP162 at the transition zone is lacking\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140657\", \"supporting_discovery_ids\": [1]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [0, 1, 6, 7]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [0, 1, 4, 6]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0005929\", \"supporting_discovery_ids\": [0, 4, 5]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [0, 4, 5, 6]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [1]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [2, 4]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"CEP290\",\n      \"CEP131\",\n      \"C2CD3\",\n      \"TUBB3\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}