{"gene":"TG_249850","gene_symbol":"GAP40","run_date":"2026-09-08T15:31:38+00:00","timeline":{"discoveries":[{"year":2010,"finding":"GAP40 was identified as a polytopic integral membrane protein of the inner membrane complex (IMC) and a component of the glideosome, where it acts as an anchor for the motor complex (MyoA-MLC1) together with GAP50.","method":"Biochemical fractionation, co-immunoprecipitation, and functional dissection of glideosome components","journal":"Cell host & microbe","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP and fractionation in a landmark study replicated by subsequent work","pmids":["20951968"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2014,"finding":"GAP40 also interacts with the class XIV myosin C (MyoC)-containing glideosome at the basal polar ring, along with GAP50, demonstrating that GAP40 is shared between the MyoA- and MyoC-glideosomes.","method":"Co-immunoprecipitation and localization studies of MyoC-glideosome components","journal":"PLoS pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP and localization, single lab, two orthogonal methods","pmids":["25393004"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2016,"finding":"GAP40 is essential for biogenesis of the IMC during intracellular replication; deletion or disruption of GAP40 caused rapid collapse of developing parasites after initiation of the cell cycle and redistribution of other glideosome components.","method":"Conditional deletion/disruption of GAP40 with phenotypic readout of IMC formation and parasite replication","journal":"PLoS pathogens","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean loss-of-function genetic approach with defined cellular phenotype (IMC collapse) and redistribution of glideosome markers as readout","pmids":["26845335"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2014,"finding":"GAP40 is firmly anchored in the IMC and serves as part of the structural anchor for the motor complex (MyoA) via interaction with GAP50; phosphorylation of GAP45 and MLC1 does not appear critical for glideosome assembly involving GAP40.","method":"Phospho-mimetic and phospho-null mutagenesis of glideosome components combined with complementation in inducible knockout background","journal":"Cellular microbiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional mutagenesis with complementation, single lab","pmids":["24779470"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2011,"finding":"GAP40 was identified as a binding partner of the integral membrane protein GAP50 via comparative affinity purification; N-glycosylation of GAP50 is required for efficient binding to GAP40 and other gliding partners.","method":"Comparative affinity purification using glycosylated vs. unglycosylated GAP50 as bait, combined with site-directed mutagenesis of N-glycosylation sites","journal":"Molecular & cellular proteomics : MCP","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — affinity purification with mutagenesis controls, single lab","pmids":["21610105"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"current_model":"GAP40 is a polytopic integral membrane protein of the Toxoplasma gondii inner membrane complex (IMC) that serves as a structural anchor shared by both the MyoA- and MyoC-containing glideosomes, is required for IMC biogenesis during intracellular replication, and interacts with GAP50 in an N-glycosylation-dependent manner to support glideosome assembly and parasite motility."},"narrative":{"mechanistic_narrative":"GAP40 is a polytopic integral membrane protein of the Toxoplasma gondii inner membrane complex (IMC) that functions as a structural anchor for the glideosome, the actomyosin motor complex driving parasite gliding motility [PMID:20951968]. It anchors the MyoA-MLC1 motor together with the integral membrane protein GAP50 [PMID:20951968], and this GAP40-GAP50 interaction depends on N-glycosylation of GAP50 [PMID:21610105]. GAP40 is shared between distinct glideosomes, associating with both the MyoA-containing motor complex and the class XIV MyoC-containing glideosome at the basal polar ring [PMID:25393004]. Beyond its scaffolding role in motility, GAP40 is essential for IMC biogenesis during intracellular replication: its loss causes rapid collapse of developing parasites and redistribution of other glideosome components [PMID:26845335].","teleology":[{"year":2010,"claim":"Establishing what physically holds the gliding motor to the IMC, GAP40 was defined as a polytopic membrane anchor for the MyoA-MLC1 motor complex, identifying a structural foundation for glideosome assembly.","evidence":"Biochemical fractionation and reciprocal co-immunoprecipitation of glideosome components","pmids":["20951968"],"confidence":"High","gaps":["Membrane topology not resolved at residue level","Direct binding interface with GAP50 not mapped"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2011,"claim":"To determine how GAP40 is recruited into the motor scaffold, the GAP40-GAP50 interaction was shown to require N-glycosylation of GAP50, linking a post-translational modification to glideosome partner assembly.","evidence":"Comparative affinity purification with glycosylated vs. unglycosylated GAP50 bait and N-glycosylation-site mutagenesis","pmids":["21610105"],"confidence":"Medium","gaps":["Whether GAP40 itself is glycosylated not addressed","Single lab, no reciprocal structural validation"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2014,"claim":"Addressing whether GAP40 serves only the MyoA motor, it was found to also associate with the MyoC-containing glideosome at the basal polar ring, showing GAP40 is a shared anchor across distinct motor complexes.","evidence":"Co-immunoprecipitation and localization studies of MyoC-glideosome components","pmids":["25393004"],"confidence":"Medium","gaps":["Whether GAP40 simultaneously binds both motors or in spatially separate pools unclear","Single lab"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2014,"claim":"To test which components' modifications are required for assembly, mutagenesis showed GAP40 anchors the MyoA motor via GAP50 independently of GAP45/MLC1 phosphorylation, delimiting the regulatory inputs to assembly.","evidence":"Phospho-mimetic/phospho-null mutagenesis with complementation in inducible knockout background","pmids":["24779470"],"confidence":"Medium","gaps":["Direct role of GAP40 phosphorylation not tested","Single lab"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2016,"claim":"Moving from binding partner to cellular requirement, conditional loss of GAP40 revealed it is essential for IMC biogenesis, establishing a structural role in daughter-cell formation beyond motor anchoring.","evidence":"Conditional deletion/disruption of GAP40 with readout of IMC formation, parasite replication, and glideosome marker redistribution","pmids":["26845335"],"confidence":"High","gaps":["Molecular mechanism linking GAP40 to IMC membrane biogenesis unresolved","Whether IMC collapse is direct or secondary to loss of glideosome integrity not distinguished"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":null,"claim":"How GAP40's polytopic membrane architecture mechanistically couples IMC biogenesis to motor anchoring, and whether the two roles are separable, remains open.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of GAP40 or its membrane topology","No mapped interaction interfaces with GAP50 or myosin partners","Mechanism of IMC membrane collapse upon GAP40 loss uncharacterized"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["MyoA-MLC1 glideosome (motor complex)","MyoC-containing glideosome (basal polar ring)"],"partners":["GAP50","MYOA","MLC1","MYOC","GAP45"],"other_free_text":["Polytopic integral membrane protein of the Toxoplasma gondii inner membrane complex (IMC).","Shared structural anchor between the MyoA- and MyoC-containing glideosomes.","GAP40-GAP50 interaction depends on N-glycosylation of GAP50.","Essential for IMC biogenesis during intracellular replication; loss causes rapid collapse of developing parasites and redistribution of glideosome components."]},"strain_conflicts":[]},"prefetch_data":{},"corpus_meta":[{"pmid":"20951968","id":"PMC_20951968","title":"Functional dissection of the apicomplexan glideosome molecular architecture.","date":"2010","source":"Cell host & microbe","url":"https://pubmed.ncbi.nlm.nih.gov/20951968","citation_count":234,"is_preprint":false},{"pmid":"25393004","id":"PMC_25393004","title":"Plasticity between MyoC- and MyoA-glideosomes: an example of functional compensation in Toxoplasma gondii invasion.","date":"2014","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/25393004","citation_count":77,"is_preprint":false},{"pmid":"26845335","id":"PMC_26845335","title":"Gliding Associated Proteins Play Essential Roles during the Formation of the Inner Membrane Complex of Toxoplasma gondii.","date":"2016","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/26845335","citation_count":52,"is_preprint":false},{"pmid":"24779470","id":"PMC_24779470","title":"Assessment of phosphorylation in Toxoplasma glideosome assembly and function.","date":"2014","source":"Cellular microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/24779470","citation_count":25,"is_preprint":false},{"pmid":"21610105","id":"PMC_21610105","title":"Unusual N-glycan structures required for trafficking Toxoplasma gondii GAP50 to the inner membrane complex regulate host cell entry through parasite motility.","date":"2011","source":"Molecular & cellular proteomics : MCP","url":"https://pubmed.ncbi.nlm.nih.gov/21610105","citation_count":23,"is_preprint":false},{"pmid":"30130043","id":"PMC_30130043","title":"[Research Advances on Gliding-associated Proteins of Toxoplasma gondii].","date":"2016","source":"Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology & parasitic diseases","url":"https://pubmed.ncbi.nlm.nih.gov/30130043","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":4951,"output_tokens":1222,"usd":0.016591,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":6183,"output_tokens":2520,"usd":0.046957,"stage2_stop_reason":"end_turn"},"total_usd":0.0,"stage1_batch_id":"msgbatch_01WgHz6kceqm573AGLyz57at","stage2_batch_id":"msgbatch_01LK4wDYj5zYquahv7gi9893","note":"batch pricing = 50% of standard","skipped":true},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2010,\n      \"finding\": \"GAP40 was identified as a polytopic integral membrane protein of the inner membrane complex (IMC) and a component of the glideosome, where it acts as an anchor for the motor complex (MyoA-MLC1) together with GAP50.\",\n      \"method\": \"Biochemical fractionation, co-immunoprecipitation, and functional dissection of glideosome components\",\n      \"journal\": \"Cell host & microbe\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP and fractionation in a landmark study replicated by subsequent work\",\n      \"pmids\": [\"20951968\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"GAP40 also interacts with the class XIV myosin C (MyoC)-containing glideosome at the basal polar ring, along with GAP50, demonstrating that GAP40 is shared between the MyoA- and MyoC-glideosomes.\",\n      \"method\": \"Co-immunoprecipitation and localization studies of MyoC-glideosome components\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP and localization, single lab, two orthogonal methods\",\n      \"pmids\": [\"25393004\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"GAP40 is essential for biogenesis of the IMC during intracellular replication; deletion or disruption of GAP40 caused rapid collapse of developing parasites after initiation of the cell cycle and redistribution of other glideosome components.\",\n      \"method\": \"Conditional deletion/disruption of GAP40 with phenotypic readout of IMC formation and parasite replication\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean loss-of-function genetic approach with defined cellular phenotype (IMC collapse) and redistribution of glideosome markers as readout\",\n      \"pmids\": [\"26845335\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"GAP40 is firmly anchored in the IMC and serves as part of the structural anchor for the motor complex (MyoA) via interaction with GAP50; phosphorylation of GAP45 and MLC1 does not appear critical for glideosome assembly involving GAP40.\",\n      \"method\": \"Phospho-mimetic and phospho-null mutagenesis of glideosome components combined with complementation in inducible knockout background\",\n      \"journal\": \"Cellular microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional mutagenesis with complementation, single lab\",\n      \"pmids\": [\"24779470\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"GAP40 was identified as a binding partner of the integral membrane protein GAP50 via comparative affinity purification; N-glycosylation of GAP50 is required for efficient binding to GAP40 and other gliding partners.\",\n      \"method\": \"Comparative affinity purification using glycosylated vs. unglycosylated GAP50 as bait, combined with site-directed mutagenesis of N-glycosylation sites\",\n      \"journal\": \"Molecular & cellular proteomics : MCP\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — affinity purification with mutagenesis controls, single lab\",\n      \"pmids\": [\"21610105\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"GAP40 is a polytopic integral membrane protein of the Toxoplasma gondii inner membrane complex (IMC) that serves as a structural anchor shared by both the MyoA- and MyoC-containing glideosomes, is required for IMC biogenesis during intracellular replication, and interacts with GAP50 in an N-glycosylation-dependent manner to support glideosome assembly and parasite motility.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"GAP40 is a polytopic integral membrane protein of the Toxoplasma gondii inner membrane complex (IMC) that functions as a structural anchor for the glideosome, the actomyosin motor complex driving parasite gliding motility [#0]. It anchors the MyoA-MLC1 motor together with the integral membrane protein GAP50 [#0], and this GAP40-GAP50 interaction depends on N-glycosylation of GAP50 [#4]. GAP40 is shared between distinct glideosomes, associating with both the MyoA-containing motor complex and the class XIV MyoC-containing glideosome at the basal polar ring [#1]. Beyond its scaffolding role in motility, GAP40 is essential for IMC biogenesis during intracellular replication: its loss causes rapid collapse of developing parasites and redistribution of other glideosome components [#2].\",\n  \"teleology\": [\n    {\n      \"year\": 2010,\n      \"claim\": \"Establishing what physically holds the gliding motor to the IMC, GAP40 was defined as a polytopic membrane anchor for the MyoA-MLC1 motor complex, identifying a structural foundation for glideosome assembly.\",\n      \"evidence\": \"Biochemical fractionation and reciprocal co-immunoprecipitation of glideosome components\",\n      \"pmids\": [\"20951968\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Membrane topology not resolved at residue level\", \"Direct binding interface with GAP50 not mapped\"],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"To determine how GAP40 is recruited into the motor scaffold, the GAP40-GAP50 interaction was shown to require N-glycosylation of GAP50, linking a post-translational modification to glideosome partner assembly.\",\n      \"evidence\": \"Comparative affinity purification with glycosylated vs. unglycosylated GAP50 bait and N-glycosylation-site mutagenesis\",\n      \"pmids\": [\"21610105\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether GAP40 itself is glycosylated not addressed\", \"Single lab, no reciprocal structural validation\"],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Addressing whether GAP40 serves only the MyoA motor, it was found to also associate with the MyoC-containing glideosome at the basal polar ring, showing GAP40 is a shared anchor across distinct motor complexes.\",\n      \"evidence\": \"Co-immunoprecipitation and localization studies of MyoC-glideosome components\",\n      \"pmids\": [\"25393004\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether GAP40 simultaneously binds both motors or in spatially separate pools unclear\", \"Single lab\"],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"To test which components' modifications are required for assembly, mutagenesis showed GAP40 anchors the MyoA motor via GAP50 independently of GAP45/MLC1 phosphorylation, delimiting the regulatory inputs to assembly.\",\n      \"evidence\": \"Phospho-mimetic/phospho-null mutagenesis with complementation in inducible knockout background\",\n      \"pmids\": [\"24779470\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct role of GAP40 phosphorylation not tested\", \"Single lab\"],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Moving from binding partner to cellular requirement, conditional loss of GAP40 revealed it is essential for IMC biogenesis, establishing a structural role in daughter-cell formation beyond motor anchoring.\",\n      \"evidence\": \"Conditional deletion/disruption of GAP40 with readout of IMC formation, parasite replication, and glideosome marker redistribution\",\n      \"pmids\": [\"26845335\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular mechanism linking GAP40 to IMC membrane biogenesis unresolved\", \"Whether IMC collapse is direct or secondary to loss of glideosome integrity not distinguished\"],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How GAP40's polytopic membrane architecture mechanistically couples IMC biogenesis to motor anchoring, and whether the two roles are separable, remains open.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of GAP40 or its membrane topology\", \"No mapped interaction interfaces with GAP50 or myosin partners\", \"Mechanism of IMC membrane collapse upon GAP40 loss uncharacterized\"],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [0, 3], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]},\n      {\"term_id\": \"GO:0005515\", \"supporting_discovery_ids\": [0, 1, 4], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0016020\", \"supporting_discovery_ids\": [0, 3], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]},\n      {\"term_id\": \"GO:0009986\", \"supporting_discovery_ids\": [1], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0071965\", \"supporting_discovery_ids\": [0, 1], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]},\n      {\"term_id\": \"GO:0051301\", \"supporting_discovery_ids\": [2], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"complexes\": [\"MyoA-MLC1 glideosome (motor complex)\", \"MyoC-containing glideosome (basal polar ring)\"],\n    \"partners\": [\"GAP50\", \"MyoA\", \"MLC1\", \"MyoC\", \"GAP45\"],\n    \"other_free_text\": [\n      \"Polytopic integral membrane protein of the Toxoplasma gondii inner membrane complex (IMC).\",\n      \"Shared structural anchor between the MyoA- and MyoC-containing glideosomes.\",\n      \"GAP40-GAP50 interaction depends on N-glycosylation of GAP50.\",\n      \"Essential for IMC biogenesis during intracellular replication; loss causes rapid collapse of developing parasites and redistribution of glideosome components.\"\n    ]\n  },\n  \"strain_conflicts\": []\n}\n```","audit_flag":null,"strains":[{"strain":"ME49","gene_id":"TGME49_249850","name":"GAP40","product":"GAP40 protein","uniprot_acc":"A0A125YP06","chromosome":"TGME49_chrXII","start_pos":4901162},{"strain":"GT1","gene_id":"TGGT1_249850","name":null,"product":"GAP40 protein","uniprot_acc":null,"chromosome":"TGGT1_chrXII","start_pos":4837577},{"strain":"RH88","gene_id":"TGRH88_063590","name":null,"product":"GAP40 protein","uniprot_acc":null,"chromosome":"CM023093","start_pos":4959524},{"strain":"VEG","gene_id":"TGVEG_249850","name":null,"product":"GAP40 protein","uniprot_acc":"B9PRA3","chromosome":"TGVEG_chrXII","start_pos":4876799}]}