{"gene":"TG_315360","gene_symbol":"INCENP2","run_date":"2026-09-08T15:15:13","timeline":{"discoveries":[{"year":2018,"finding":"Toxoplasma gondii INCENP2 (TgINCENP2) is a subunit of the chromosomal passenger complex (CPC) together with Aurora kinase 1 (TgArk1) and TgINCENP1, as demonstrated by interaction studies showing TgArk1 interacts with both TgINCENPs.","method":"Co-immunoprecipitation / interaction assays establishing complex membership","journal":"Cellular and molecular life sciences : CMLS","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — reciprocal interaction demonstrated in a single lab, single study; complex membership inferred from pull-down/Co-IP data described in abstract without independent replication","pmids":["30051161"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2018,"finding":"TgINCENP2 is essential for translocation of TgArk1 to the nucleus; loss of TgINCENP2 function prevents nuclear localization of the Aurora kinase 1 subunit of the CPC.","method":"Loss-of-function mutant analysis combined with subcellular localization imaging (fluorescence microscopy)","journal":"Cellular and molecular life sciences : CMLS","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — localization phenotype tied to functional consequence (nuclear translocation of TgArk1) via loss-of-function in a single lab study","pmids":["30051161"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2018,"finding":"TgINCENP2 is essential for proper cell division and parasite growth; interference with TgINCENP2 causes pronounced division and growth defects, whereas TgINCENP1 appears dispensable.","method":"Loss-of-function genetic interference with phenotypic readout (division defects, growth assay)","journal":"Cellular and molecular life sciences : CMLS","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — clean loss-of-function with defined cellular phenotype in a single lab, single study","pmids":["30051161"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2018,"finding":"The Toxoplasma CPC (TgArk1/TgINCENP1/TgINCENP2) exhibits dynamic, cell cycle-dependent localization, consistent with its role in organizing a functional mitotic spindle during endodyogeny.","method":"Fluorescence microscopy / cell cycle-staged localization analysis","journal":"Cellular and molecular life sciences : CMLS","confidence":"Low","confidence_rationale":"Tier 3 / Weak — localization described in a single study without full functional dissection of the dynamic pattern per se","pmids":["30051161"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"current_model":"TgINCENP2 is an essential subunit of the Toxoplasma chromosomal passenger complex (CPC) that interacts with Aurora kinase 1 (TgArk1) and is required for TgArk1 nuclear translocation, proper mitotic spindle organization, and faithful endodyogeny-based cell division."},"narrative":{"mechanistic_narrative":"TgINCENP2 is an essential subunit of the Toxoplasma gondii chromosomal passenger complex (CPC), which it forms together with Aurora kinase 1 (TgArk1) and TgINCENP1 [PMID:30051161]. Within this complex, TgINCENP2 is required for translocation of TgArk1 to the nucleus, since loss of TgINCENP2 function prevents the Aurora kinase from reaching its nuclear compartment [PMID:30051161]. Functionally, TgINCENP2 is indispensable for faithful cell division and parasite growth—its interference produces pronounced division and growth defects, whereas TgINCENP1 is dispensable [PMID:30051161]. Beyond its role in CPC assembly and TgArk1 targeting during endodyogeny, no further mechanistic detail has been characterized in the available corpus.","teleology":[{"year":2018,"claim":"Establishing whether TgINCENP2 is a bona fide component of the Toxoplasma CPC answered how the parasite organizes an Aurora-kinase-based mitotic machinery, placing TgINCENP2 alongside TgArk1 and TgINCENP1.","evidence":"Co-immunoprecipitation / interaction assays showing TgArk1 binds both TgINCENPs","pmids":["30051161"],"confidence":"Medium","gaps":["Complex membership inferred from Co-IP in a single lab without independent replication","Stoichiometry and direct versus indirect binding within the complex not resolved","No structural model of the TgINCENP2-TgArk1 interface"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2018,"claim":"Determining that TgINCENP2 is required for nuclear delivery of TgArk1 clarified a functional hierarchy within the CPC, showing TgINCENP2 acts upstream of the kinase's subcellular targeting.","evidence":"Loss-of-function mutant analysis with fluorescence localization of TgArk1","pmids":["30051161"],"confidence":"Medium","gaps":["Molecular mechanism of TgArk1 nuclear import via TgINCENP2 unknown","Whether TgINCENP1 contributes to TgArk1 targeting not distinguished"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2018,"claim":"Testing the requirement of each INCENP for viability showed TgINCENP2, but not TgINCENP1, is essential for division and growth, defining TgINCENP2 as the functionally critical CPC subunit.","evidence":"Genetic loss-of-function interference with division and growth phenotypic readouts","pmids":["30051161"],"confidence":"Medium","gaps":["Molecular basis for the differential essentiality of TgINCENP1 versus TgINCENP2 not defined","Specific division step (spindle assembly, segregation, budding) that fails unresolved"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2018,"claim":"Cell cycle-staged imaging showed the CPC displays dynamic localization consistent with organizing the mitotic spindle during endodyogeny, linking TgINCENP2 to spindle-associated events.","evidence":"Fluorescence microscopy across cell cycle stages","pmids":["30051161"],"confidence":"Low","gaps":["Dynamic localization described without functional dissection of the pattern","Direct role of TgINCENP2 in spindle organization not mechanistically demonstrated"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":null,"claim":"How TgINCENP2 mediates TgArk1 nuclear import at the molecular level and what spindle or chromosomal substrates the CPC acts on during endodyogeny remain unknown.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural or biochemical characterization of the TgINCENP2-TgArk1 interaction","Substrates phosphorylated by the TgArk1/TgINCENP2 complex unidentified","Mechanism of the dynamic cell cycle-dependent localization not defined"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["Chromosomal passenger complex (TgArk1/TgINCENP1/TgINCENP2)"],"partners":["TGARK1 (AURORA KINASE 1)","TGINCENP1"],"other_free_text":["Required for nuclear translocation of TgArk1 [#1]","Essential for endodyogeny-based cell division and parasite growth, unlike TgINCENP1 which is dispensable [#2]"]},"strain_conflicts":[]},"prefetch_data":{},"corpus_meta":[{"pmid":"30051161","id":"PMC_30051161","title":"Toxoplasma gondii chromosomal passenger complex is essential for the organization of a functional mitotic spindle: a prerequisite for productive endodyogeny.","date":"2018","source":"Cellular and molecular life sciences : CMLS","url":"https://pubmed.ncbi.nlm.nih.gov/30051161","citation_count":22,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":3087,"output_tokens":989,"usd":0.012048,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":5876,"output_tokens":2139,"usd":0.041427,"stage2_stop_reason":"end_turn"},"total_usd":0.053475,"stage1_batch_id":"msgbatch_01S6GjoYQm8LTPUsdhASdqag","stage2_batch_id":"msgbatch_01VX63RTMdBJqsG6gQMqoCjz","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2018,\n      \"finding\": \"Toxoplasma gondii INCENP2 (TgINCENP2) is a subunit of the chromosomal passenger complex (CPC) together with Aurora kinase 1 (TgArk1) and TgINCENP1, as demonstrated by interaction studies showing TgArk1 interacts with both TgINCENPs.\",\n      \"method\": \"Co-immunoprecipitation / interaction assays establishing complex membership\",\n      \"journal\": \"Cellular and molecular life sciences : CMLS\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — reciprocal interaction demonstrated in a single lab, single study; complex membership inferred from pull-down/Co-IP data described in abstract without independent replication\",\n      \"pmids\": [\"30051161\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"TgINCENP2 is essential for translocation of TgArk1 to the nucleus; loss of TgINCENP2 function prevents nuclear localization of the Aurora kinase 1 subunit of the CPC.\",\n      \"method\": \"Loss-of-function mutant analysis combined with subcellular localization imaging (fluorescence microscopy)\",\n      \"journal\": \"Cellular and molecular life sciences : CMLS\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — localization phenotype tied to functional consequence (nuclear translocation of TgArk1) via loss-of-function in a single lab study\",\n      \"pmids\": [\"30051161\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"TgINCENP2 is essential for proper cell division and parasite growth; interference with TgINCENP2 causes pronounced division and growth defects, whereas TgINCENP1 appears dispensable.\",\n      \"method\": \"Loss-of-function genetic interference with phenotypic readout (division defects, growth assay)\",\n      \"journal\": \"Cellular and molecular life sciences : CMLS\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — clean loss-of-function with defined cellular phenotype in a single lab, single study\",\n      \"pmids\": [\"30051161\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"The Toxoplasma CPC (TgArk1/TgINCENP1/TgINCENP2) exhibits dynamic, cell cycle-dependent localization, consistent with its role in organizing a functional mitotic spindle during endodyogeny.\",\n      \"method\": \"Fluorescence microscopy / cell cycle-staged localization analysis\",\n      \"journal\": \"Cellular and molecular life sciences : CMLS\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — localization described in a single study without full functional dissection of the dynamic pattern per se\",\n      \"pmids\": [\"30051161\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"TgINCENP2 is an essential subunit of the Toxoplasma chromosomal passenger complex (CPC) that interacts with Aurora kinase 1 (TgArk1) and is required for TgArk1 nuclear translocation, proper mitotic spindle organization, and faithful endodyogeny-based cell division.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"TgINCENP2 is an essential subunit of the Toxoplasma gondii chromosomal passenger complex (CPC), which it forms together with Aurora kinase 1 (TgArk1) and TgINCENP1 [#0]. Within this complex, TgINCENP2 is required for translocation of TgArk1 to the nucleus, since loss of TgINCENP2 function prevents the Aurora kinase from reaching its nuclear compartment [#1]. Functionally, TgINCENP2 is indispensable for faithful cell division and parasite growth—its interference produces pronounced division and growth defects, whereas TgINCENP1 is dispensable [#2]. Beyond its role in CPC assembly and TgArk1 targeting during endodyogeny, no further mechanistic detail has been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2018,\n      \"claim\": \"Establishing whether TgINCENP2 is a bona fide component of the Toxoplasma CPC answered how the parasite organizes an Aurora-kinase-based mitotic machinery, placing TgINCENP2 alongside TgArk1 and TgINCENP1.\",\n      \"evidence\": \"Co-immunoprecipitation / interaction assays showing TgArk1 binds both TgINCENPs\",\n      \"pmids\": [\"30051161\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Complex membership inferred from Co-IP in a single lab without independent replication\",\n        \"Stoichiometry and direct versus indirect binding within the complex not resolved\",\n        \"No structural model of the TgINCENP2-TgArk1 interface\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Determining that TgINCENP2 is required for nuclear delivery of TgArk1 clarified a functional hierarchy within the CPC, showing TgINCENP2 acts upstream of the kinase's subcellular targeting.\",\n      \"evidence\": \"Loss-of-function mutant analysis with fluorescence localization of TgArk1\",\n      \"pmids\": [\"30051161\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular mechanism of TgArk1 nuclear import via TgINCENP2 unknown\",\n        \"Whether TgINCENP1 contributes to TgArk1 targeting not distinguished\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Testing the requirement of each INCENP for viability showed TgINCENP2, but not TgINCENP1, is essential for division and growth, defining TgINCENP2 as the functionally critical CPC subunit.\",\n      \"evidence\": \"Genetic loss-of-function interference with division and growth phenotypic readouts\",\n      \"pmids\": [\"30051161\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular basis for the differential essentiality of TgINCENP1 versus TgINCENP2 not defined\",\n        \"Specific division step (spindle assembly, segregation, budding) that fails unresolved\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Cell cycle-staged imaging showed the CPC displays dynamic localization consistent with organizing the mitotic spindle during endodyogeny, linking TgINCENP2 to spindle-associated events.\",\n      \"evidence\": \"Fluorescence microscopy across cell cycle stages\",\n      \"pmids\": [\"30051161\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Dynamic localization described without functional dissection of the pattern\",\n        \"Direct role of TgINCENP2 in spindle organization not mechanistically demonstrated\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How TgINCENP2 mediates TgArk1 nuclear import at the molecular level and what spindle or chromosomal substrates the CPC acts on during endodyogeny remain unknown.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No structural or biochemical characterization of the TgINCENP2-TgArk1 interaction\",\n        \"Substrates phosphorylated by the TgArk1/TgINCENP2 complex unidentified\",\n        \"Mechanism of the dynamic cell cycle-dependent localization not defined\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [1], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]},\n      {\"term_id\": \"GO:0005819\", \"supporting_discovery_ids\": [3], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0051301\", \"supporting_discovery_ids\": [2], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]},\n      {\"term_id\": \"GO:0007052\", \"supporting_discovery_ids\": [3], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"complexes\": [\"Chromosomal passenger complex (TgArk1/TgINCENP1/TgINCENP2)\"],\n    \"partners\": [\"TgArk1 (Aurora kinase 1)\", \"TgINCENP1\"],\n    \"other_free_text\": [\n      \"Required for nuclear translocation of TgArk1 [#1]\",\n      \"Essential for endodyogeny-based cell division and parasite growth, unlike TgINCENP1 which is dispensable [#2]\"\n    ]\n  },\n  \"strain_conflicts\": []\n}\n```","audit_flag":null,"strains":[{"strain":"ME49","gene_id":"TGME49_315360","name":"INCENP2","product":"inner centromere protein INCENP2","uniprot_acc":"A0A125YSY0","chromosome":"TGME49_chrXI","start_pos":4669781},{"strain":"GT1","gene_id":"TGGT1_315360","name":null,"product":"hypothetical protein","uniprot_acc":null,"chromosome":"TGGT1_chrXI","start_pos":4614506},{"strain":"RH88","gene_id":"TGRH88_054220","name":null,"product":"unspecified product","uniprot_acc":null,"chromosome":"CM023092","start_pos":4736616},{"strain":"VEG","gene_id":"TGVEG_315360","name":null,"product":"inner centromere protein, ARK-binding region protein","uniprot_acc":"B6K9J1","chromosome":"TGVEG_chrXI","start_pos":4693190}]}