{"gene":"CENPO","run_date":"2026-06-09T22:57:18","timeline":{"discoveries":[{"year":2007,"finding":"CENP-O, -P, -Q, and -50 (U) form a stable four-subunit complex that can associate with CENP-R, as demonstrated by coexpression in bacteria; kinetochore localization of CENP-O, -P, -Q, and -50 is interdependent, but CENP-R localization is independent of the other four subunits.","method":"Bacterial coexpression assay, DT40 knockout cell lines with kinetochore localization analysis","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — in vitro reconstitution in bacteria plus multiple genetic knockouts with localization readout; replicated across multiple subunit knockouts","pmids":["18094054"],"is_preprint":false},{"year":2007,"finding":"CENP-O class proteins (except CENP-R) are required for recovery from spindle damage, and phosphorylation of CENP-50 (CENP-U) is essential for this recovery; loss of CENP-50 leads to premature sister chromatid separation that can be partially rescued by proteasome inhibition with MG132.","method":"DT40 knockout cell lines, nocodazole block/release assay, MG132 rescue experiment","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean genetic knockouts with defined phenotypic readout and pharmacological rescue; multiple subunit comparisons in same study","pmids":["18094054"],"is_preprint":false},{"year":2014,"finding":"CENP-U (CENP-50) deficiency causes all CENP-O complex proteins (CENP-O, -P, -Q, -R, -U) to disappear from kinetochores in mouse ES cells, while other kinetochore proteins are still recruited, establishing CENP-U as a master scaffold for CENP-O complex kinetochore localization.","method":"Conditional knockout mouse ES cells, kinetochore protein localization by immunofluorescence","journal":"Chromosome research","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional knockout with systematic localization analysis of multiple kinetochore components; phenotype replicated in multiple cell types","pmids":["24481920"],"is_preprint":false},{"year":2021,"finding":"The CENP-O complex and BUB1 act in parallel pathways to recruit a threshold level of PLK1 to mitotic kinetochores; loss of either pathway sensitizes cells to loss of the other, demonstrating epistatic parallelism in PLK1 kinetochore recruitment.","method":"Genome-wide essentiality screens across cell lines, genetic perturbation of CENP-O complex and BUB1 with PLK1 kinetochore localization readout","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis across multiple cell lines with defined molecular readout (PLK1 kinetochore levels) and synthetic sensitization experiments","pmids":["33596090"],"is_preprint":false},{"year":2021,"finding":"Within the human CENP-O complex, residues 241–360 of CENP-U and the C-terminal half of CENP-Q are essential for forming the CENP-U/Q heterocomplex and for interacting with the CENP-O/P sub-complex; CENP-R does not directly interact with CENP-O/P but interacts with CENP-U and CENP-Q through both its N- and C-termini.","method":"In vitro binding assays with defined protein fragments","journal":"Journal of molecular recognition","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — in vitro reconstitution with domain mapping, but single lab and abstract lacks full mutagenesis/structural validation detail","pmids":["33660361"],"is_preprint":false}],"current_model":"CENPO is a constitutive kinetochore protein that assembles with CENP-P, CENP-Q, CENP-U, and CENP-R into the CENP-O complex, where CENP-U acts as a master scaffold for complex kinetochore localization; the complex functions in parallel with BUB1 to recruit threshold levels of PLK1 to mitotic kinetochores, and is required for recovery from spindle damage by preventing premature sister chromatid separation in a phosphorylation-dependent (CENP-U phosphorylation) and proteasome-regulated manner."},"narrative":{"mechanistic_narrative":"CENPO is a constitutive kinetochore protein that assembles into the CENP-O complex with CENP-P, CENP-Q, CENP-U (CENP-50), and CENP-R, functioning in faithful mitotic chromosome segregation and recovery from spindle damage [PMID:18094054]. The four core subunits (CENP-O, -P, -Q, -U) form a stable complex whose kinetochore localization is interdependent, with CENP-R associating peripherally and localizing independently of the others [PMID:18094054]; CENP-U serves as the master scaffold, since its loss removes all CENP-O complex members from kinetochores while leaving other kinetochore proteins intact [PMID:24481920]. Architecturally, a defined region of CENP-U together with the CENP-Q C-terminus forms the CENP-U/Q heterocomplex that bridges to the CENP-O/P sub-complex, and CENP-R is tethered through interactions with CENP-U and CENP-Q rather than CENP-O/P [PMID:33660361]. Functionally, the complex is required for recovery from spindle damage, preventing premature sister chromatid separation in a manner dependent on CENP-U phosphorylation and reversible by proteasome inhibition [PMID:18094054], and it acts in parallel with BUB1 to recruit threshold levels of PLK1 to mitotic kinetochores, such that loss of one pathway sensitizes cells to loss of the other [PMID:33596090].","teleology":[{"year":2007,"claim":"Established that CENP-O is a subunit of a discrete, stably assembled kinetochore complex rather than an isolated factor, defining its physical context.","evidence":"Bacterial coexpression reconstitution and DT40 knockout localization analysis","pmids":["18094054"],"confidence":"High","gaps":["Did not resolve subunit stoichiometry or atomic architecture","CENP-R's mode of association left only partially defined"]},{"year":2007,"claim":"Linked the complex to a cellular function — recovery from spindle damage — and identified CENP-U phosphorylation and proteasome regulation as control points for preventing premature sister chromatid separation.","evidence":"DT40 knockouts with nocodazole block/release and MG132 rescue","pmids":["18094054"],"confidence":"High","gaps":["Kinase responsible for CENP-U phosphorylation not identified","Proteasome substrate driving premature separation not defined","CENP-O-specific contribution versus other subunits not isolated"]},{"year":2014,"claim":"Resolved the assembly hierarchy by showing CENP-U is the master scaffold whose loss collapses kinetochore localization of all CENP-O complex members.","evidence":"Conditional knockout mouse ES cells with immunofluorescence of kinetochore proteins","pmids":["24481920"],"confidence":"High","gaps":["Receptor at the kinetochore that recruits CENP-U not identified","Does not establish CENP-O's specific structural role within the complex"]},{"year":2021,"claim":"Placed the complex in a defined molecular pathway by showing it acts in parallel with BUB1 to set threshold PLK1 levels at kinetochores, explaining synthetic genetic vulnerabilities.","evidence":"Genome-wide essentiality screens and genetic perturbation with PLK1 kinetochore localization readout","pmids":["33596090"],"confidence":"High","gaps":["Molecular bridge connecting the complex to PLK1 not mapped","Specific CENP-O subunit mediating PLK1 recruitment not pinpointed"]},{"year":2021,"claim":"Mapped the internal interaction architecture, defining the CENP-U/Q heterocomplex and how it bridges CENP-O/P and tethers CENP-R.","evidence":"In vitro binding assays with defined protein fragments","pmids":["33660361"],"confidence":"Medium","gaps":["Single-lab domain mapping without full structural validation","No high-resolution structure of the assembled complex","Quantitative affinities of interactions not determined"]},{"year":null,"claim":"How CENP-U phosphorylation, proteasome activity, and PLK1 recruitment are mechanistically coupled to spindle-damage recovery remains unresolved.","evidence":"","pmids":[],"confidence":"High","gaps":["No identified kinase/phosphatase circuit controlling CENP-U","No structural model of the complex bound to its kinetochore receptor or to PLK1"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,2,4]}],"localization":[{"term_id":"GO:0005694","term_label":"chromosome","supporting_discovery_ids":[0,2]}],"pathway":[{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[1,3]}],"complexes":["CENP-O complex","kinetochore"],"partners":["CENPP","CENPQ","CENPU","CENPR","BUB1","PLK1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9BU64","full_name":"Centromere protein O","aliases":["Interphase centromere complex protein 36"],"length_aa":300,"mass_kda":33.8,"function":"Component of the CENPA-CAD (nucleosome distal) complex, a complex recruited to centromeres which is involved in assembly of kinetochore proteins, mitotic progression and chromosome segregation. May be involved in incorporation of newly synthesized CENPA into centromeres via its interaction with the CENPA-NAC complex. Modulates the kinetochore-bound levels of NDC80 complex","subcellular_location":"Nucleus; Chromosome, centromere; Chromosome, centromere, kinetochore","url":"https://www.uniprot.org/uniprotkb/Q9BU64/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CENPO","classification":"Not Classified","n_dependent_lines":131,"n_total_lines":1208,"dependency_fraction":0.10844370860927152},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/CENPO","total_profiled":1310},"omim":[{"mim_id":"611511","title":"MLF1-INTERACTING PROTEIN; MLF1IP","url":"https://www.omim.org/entry/611511"},{"mim_id":"611506","title":"CENTROMERIC PROTEIN Q; CENPQ","url":"https://www.omim.org/entry/611506"},{"mim_id":"611505","title":"CENTROMERIC PROTEIN P; CENPP","url":"https://www.omim.org/entry/611505"},{"mim_id":"611504","title":"CENTROMERIC PROTEIN O; CENPO","url":"https://www.omim.org/entry/611504"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"},{"location":"Nuclear bodies","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/CENPO"},"hgnc":{"alias_symbol":["MGC11266","CENP-O"],"prev_symbol":[]},"alphafold":{"accession":"Q9BU64","domains":[{"cath_id":"3.30.457","chopping":"112-189","consensus_level":"medium","plddt":95.1826,"start":112,"end":189},{"cath_id":"3.30.457","chopping":"193-297","consensus_level":"medium","plddt":84.5569,"start":193,"end":297}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9BU64","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9BU64-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9BU64-F1-predicted_aligned_error_v6.png","plddt_mean":85.19},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CENPO","jax_strain_url":"https://www.jax.org/strain/search?query=CENPO"},"sequence":{"accession":"Q9BU64","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9BU64.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9BU64/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9BU64"}},"corpus_meta":[{"pmid":"18094054","id":"PMC_18094054","title":"CENP-O class proteins form a stable complex and are required for proper kinetochore function.","date":"2007","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/18094054","citation_count":114,"is_preprint":false},{"pmid":"24481920","id":"PMC_24481920","title":"The CENP-O complex requirement varies among different cell types.","date":"2014","source":"Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology","url":"https://pubmed.ncbi.nlm.nih.gov/24481920","citation_count":32,"is_preprint":false},{"pmid":"33596090","id":"PMC_33596090","title":"Differential requirements for the CENP-O complex reveal parallel PLK1 kinetochore recruitment pathways.","date":"2021","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/33596090","citation_count":22,"is_preprint":false},{"pmid":"19286853","id":"PMC_19286853","title":"CENP-O, a protein localized at the centromere throughout the cell cycle, is a novel target antigen in systemic sclerosis.","date":"2009","source":"The Journal of rheumatology","url":"https://pubmed.ncbi.nlm.nih.gov/19286853","citation_count":15,"is_preprint":false},{"pmid":"35201521","id":"PMC_35201521","title":"CENPO regulated proliferation and apoptosis of colorectal cancer in a p53-dependent manner.","date":"2022","source":"Discover oncology","url":"https://pubmed.ncbi.nlm.nih.gov/35201521","citation_count":13,"is_preprint":false},{"pmid":"37061713","id":"PMC_37061713","title":"Pan-cancer landscape of CENPO and its underlying mechanism in LUAD.","date":"2023","source":"Respiratory research","url":"https://pubmed.ncbi.nlm.nih.gov/37061713","citation_count":7,"is_preprint":false},{"pmid":"33660361","id":"PMC_33660361","title":"The novel interaction mode among centromere sub-complex CENP-O/P/U/Q/R.","date":"2021","source":"Journal of molecular recognition : JMR","url":"https://pubmed.ncbi.nlm.nih.gov/33660361","citation_count":4,"is_preprint":false},{"pmid":"37207381","id":"PMC_37207381","title":"Advances in lung adenocarcinoma: A novel perspective on prognoses and immune responses of CENPO as an oncogenic superenhancer.","date":"2023","source":"Translational oncology","url":"https://pubmed.ncbi.nlm.nih.gov/37207381","citation_count":2,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":6024,"output_tokens":1292,"usd":0.018726,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":7873,"output_tokens":1923,"usd":0.04372,"stage2_stop_reason":"end_turn"},"total_usd":0.062446,"stage1_batch_id":"msgbatch_01ACAxJQabDsht39JXeWG22d","stage2_batch_id":"msgbatch_01QEU22A9U5sbPTgsMzTmvSf","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2007,\n      \"finding\": \"CENP-O, -P, -Q, and -50 (U) form a stable four-subunit complex that can associate with CENP-R, as demonstrated by coexpression in bacteria; kinetochore localization of CENP-O, -P, -Q, and -50 is interdependent, but CENP-R localization is independent of the other four subunits.\",\n      \"method\": \"Bacterial coexpression assay, DT40 knockout cell lines with kinetochore localization analysis\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — in vitro reconstitution in bacteria plus multiple genetic knockouts with localization readout; replicated across multiple subunit knockouts\",\n      \"pmids\": [\"18094054\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"CENP-O class proteins (except CENP-R) are required for recovery from spindle damage, and phosphorylation of CENP-50 (CENP-U) is essential for this recovery; loss of CENP-50 leads to premature sister chromatid separation that can be partially rescued by proteasome inhibition with MG132.\",\n      \"method\": \"DT40 knockout cell lines, nocodazole block/release assay, MG132 rescue experiment\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean genetic knockouts with defined phenotypic readout and pharmacological rescue; multiple subunit comparisons in same study\",\n      \"pmids\": [\"18094054\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"CENP-U (CENP-50) deficiency causes all CENP-O complex proteins (CENP-O, -P, -Q, -R, -U) to disappear from kinetochores in mouse ES cells, while other kinetochore proteins are still recruited, establishing CENP-U as a master scaffold for CENP-O complex kinetochore localization.\",\n      \"method\": \"Conditional knockout mouse ES cells, kinetochore protein localization by immunofluorescence\",\n      \"journal\": \"Chromosome research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional knockout with systematic localization analysis of multiple kinetochore components; phenotype replicated in multiple cell types\",\n      \"pmids\": [\"24481920\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"The CENP-O complex and BUB1 act in parallel pathways to recruit a threshold level of PLK1 to mitotic kinetochores; loss of either pathway sensitizes cells to loss of the other, demonstrating epistatic parallelism in PLK1 kinetochore recruitment.\",\n      \"method\": \"Genome-wide essentiality screens across cell lines, genetic perturbation of CENP-O complex and BUB1 with PLK1 kinetochore localization readout\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis across multiple cell lines with defined molecular readout (PLK1 kinetochore levels) and synthetic sensitization experiments\",\n      \"pmids\": [\"33596090\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Within the human CENP-O complex, residues 241–360 of CENP-U and the C-terminal half of CENP-Q are essential for forming the CENP-U/Q heterocomplex and for interacting with the CENP-O/P sub-complex; CENP-R does not directly interact with CENP-O/P but interacts with CENP-U and CENP-Q through both its N- and C-termini.\",\n      \"method\": \"In vitro binding assays with defined protein fragments\",\n      \"journal\": \"Journal of molecular recognition\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — in vitro reconstitution with domain mapping, but single lab and abstract lacks full mutagenesis/structural validation detail\",\n      \"pmids\": [\"33660361\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CENPO is a constitutive kinetochore protein that assembles with CENP-P, CENP-Q, CENP-U, and CENP-R into the CENP-O complex, where CENP-U acts as a master scaffold for complex kinetochore localization; the complex functions in parallel with BUB1 to recruit threshold levels of PLK1 to mitotic kinetochores, and is required for recovery from spindle damage by preventing premature sister chromatid separation in a phosphorylation-dependent (CENP-U phosphorylation) and proteasome-regulated manner.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"CENPO is a constitutive kinetochore protein that assembles into the CENP-O complex with CENP-P, CENP-Q, CENP-U (CENP-50), and CENP-R, functioning in faithful mitotic chromosome segregation and recovery from spindle damage [#0, #1]. The four core subunits (CENP-O, -P, -Q, -U) form a stable complex whose kinetochore localization is interdependent, with CENP-R associating peripherally and localizing independently of the others [#0]; CENP-U serves as the master scaffold, since its loss removes all CENP-O complex members from kinetochores while leaving other kinetochore proteins intact [#2]. Architecturally, a defined region of CENP-U together with the CENP-Q C-terminus forms the CENP-U/Q heterocomplex that bridges to the CENP-O/P sub-complex, and CENP-R is tethered through interactions with CENP-U and CENP-Q rather than CENP-O/P [#4]. Functionally, the complex is required for recovery from spindle damage, preventing premature sister chromatid separation in a manner dependent on CENP-U phosphorylation and reversible by proteasome inhibition [#1], and it acts in parallel with BUB1 to recruit threshold levels of PLK1 to mitotic kinetochores, such that loss of one pathway sensitizes cells to loss of the other [#3].\",\n  \"teleology\": [\n    {\n      \"year\": 2007,\n      \"claim\": \"Established that CENP-O is a subunit of a discrete, stably assembled kinetochore complex rather than an isolated factor, defining its physical context.\",\n      \"evidence\": \"Bacterial coexpression reconstitution and DT40 knockout localization analysis\",\n      \"pmids\": [\"18094054\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve subunit stoichiometry or atomic architecture\", \"CENP-R's mode of association left only partially defined\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Linked the complex to a cellular function — recovery from spindle damage — and identified CENP-U phosphorylation and proteasome regulation as control points for preventing premature sister chromatid separation.\",\n      \"evidence\": \"DT40 knockouts with nocodazole block/release and MG132 rescue\",\n      \"pmids\": [\"18094054\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Kinase responsible for CENP-U phosphorylation not identified\", \"Proteasome substrate driving premature separation not defined\", \"CENP-O-specific contribution versus other subunits not isolated\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Resolved the assembly hierarchy by showing CENP-U is the master scaffold whose loss collapses kinetochore localization of all CENP-O complex members.\",\n      \"evidence\": \"Conditional knockout mouse ES cells with immunofluorescence of kinetochore proteins\",\n      \"pmids\": [\"24481920\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Receptor at the kinetochore that recruits CENP-U not identified\", \"Does not establish CENP-O's specific structural role within the complex\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Placed the complex in a defined molecular pathway by showing it acts in parallel with BUB1 to set threshold PLK1 levels at kinetochores, explaining synthetic genetic vulnerabilities.\",\n      \"evidence\": \"Genome-wide essentiality screens and genetic perturbation with PLK1 kinetochore localization readout\",\n      \"pmids\": [\"33596090\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular bridge connecting the complex to PLK1 not mapped\", \"Specific CENP-O subunit mediating PLK1 recruitment not pinpointed\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Mapped the internal interaction architecture, defining the CENP-U/Q heterocomplex and how it bridges CENP-O/P and tethers CENP-R.\",\n      \"evidence\": \"In vitro binding assays with defined protein fragments\",\n      \"pmids\": [\"33660361\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single-lab domain mapping without full structural validation\", \"No high-resolution structure of the assembled complex\", \"Quantitative affinities of interactions not determined\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How CENP-U phosphorylation, proteasome activity, and PLK1 recruitment are mechanistically coupled to spindle-damage recovery remains unresolved.\",\n      \"evidence\": null,\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No identified kinase/phosphatase circuit controlling CENP-U\", \"No structural model of the complex bound to its kinetochore receptor or to PLK1\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 2, 4]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005694\", \"supporting_discovery_ids\": [0, 2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [1, 3]}\n    ],\n    \"complexes\": [\"CENP-O complex\", \"kinetochore\"],\n    \"partners\": [\"CENPP\", \"CENPQ\", \"CENPU\", \"CENPR\", \"BUB1\", \"PLK1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":4,"faith_total":4,"faith_pct":100.0}}