{"gene":"TG_315780","gene_symbol":"MLC7","run_date":"2026-09-08T15:15:13","timeline":{"discoveries":[{"year":2016,"finding":"MLC7 was identified as a myosin light chain associated with MyoH (class XIV myosin H) at the conoid of Toxoplasma gondii; MyoH and its associated light chains (including MLC7) are required for parasite motility, invasion, and egress from host cells, and the 3 alpha-tubulin suppressor domains in the MyoH tail anchor this motor complex to the conoid.","method":"Conditional disruption of MyoH, subcellular localization, phenotypic analysis of motility/invasion/egress","journal":"PLoS pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — conditional KO with defined cellular phenotype and localization; MLC7 identified as MyoH light chain but mechanistic characterization of MLC7 itself is limited to its association with MyoH","pmids":["26760042"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2017,"finding":"BirA-based proximity biotinylation using calmodulin-like proteins (CaM1, CaM2, CaM3) labeled apical proteins including MyoH and its light chain MLC7 at the conoid, suggesting MLC7 is part of the apical MyoH motor complex; disruption of MyoH led to degradation of CaM3 or redistribution of CaM1/CaM2, indicating interdependence between conoid CaMs and the MyoH-MLC7 complex.","method":"BirA proximity biotinylation, CRISPR/Cas9-mediated gene editing, auxin-induced degron (AID) system, super-resolution microscopy","journal":"PLoS pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — proximity biotinylation identifies MLC7 as a MyoH-associated protein; interaction is inferred from biotinylation data rather than direct co-IP or reconstitution","pmids":["28475612"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2011,"finding":"A survey of calmodulin-like proteins in Apicomplexa identified six putative myosin light chains in T. gondii including MLC7; their subcellular localizations were determined, establishing that MLC7 is one of several CaM-domain-containing light chains in the T. gondii myosin repertoire.","method":"Subcellular localization by fluorescence microscopy, bioinformatic identification of CaM-like proteins","journal":"Traffic (Copenhagen, Denmark)","confidence":"Low","confidence_rationale":"Tier 3 / Weak — MLC7 identified in a repertoire survey with localization data; no direct functional characterization of MLC7 itself reported","pmids":["21143563"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"current_model":"MLC7 is a calmodulin-like myosin light chain that associates with class XIV myosin H (MyoH) at the conoid of Toxoplasma gondii, where it forms part of a motor complex required for parasite motility, invasion, and egress from host cells, and is also in proximity to conoid-localized calmodulin-like proteins (CaM1–3) that functionally depend on MyoH integrity."},"narrative":{"mechanistic_narrative":"MLC7 is a calmodulin-like myosin light chain of Toxoplasma gondii that operates as a component of the apical class XIV myosin H (MyoH) motor complex at the conoid, where this motor drives parasite motility, host-cell invasion, and egress [PMID:26760042]. MLC7 associates with MyoH, whose tail carries three alpha-tubulin suppressor domains that anchor the motor complex to the conoid [PMID:26760042], and proximity-biotinylation places MLC7 together with MyoH and the conoid calmodulin-like proteins CaM1–CaM3, whose stability and distribution depend on an intact MyoH–MLC7 complex [PMID:28475612]. MLC7 is one of several CaM-domain light chains in the parasite's myosin repertoire [PMID:21143563]. Beyond its assignment to the MyoH motor complex and its conoid localization, no direct biochemical or structural characterization of MLC7 itself has been reported in the available corpus.","teleology":[{"year":2011,"claim":"Before any functional assignment, it was unknown which calmodulin-like proteins served as myosin light chains in Toxoplasma; a repertoire survey established MLC7 as one of six CaM-domain-containing candidate light chains with a defined subcellular localization.","evidence":"Bioinformatic identification of CaM-like proteins with fluorescence-microscopy localization in T. gondii","pmids":["21143563"],"confidence":"Low","gaps":["No direct functional characterization of MLC7 itself","Cognate myosin partner not defined at this stage","No demonstration of light-chain activity"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2016,"claim":"It was unknown which myosin MLC7 partners with and what cellular process that motor serves; conditional disruption of MyoH showed MLC7 is a MyoH-associated light chain of a conoid motor complex required for motility, invasion, and egress.","evidence":"Conditional disruption of MyoH with subcellular localization and phenotypic analysis of motility/invasion/egress in T. gondii","pmids":["26760042"],"confidence":"Medium","gaps":["MLC7's own contribution not tested by direct MLC7 loss-of-function","Direct MLC7–MyoH binding not biochemically reconstituted","Role of MLC7 in motor mechanochemistry not defined"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2017,"claim":"Whether MLC7 sits within a broader conoid apical complex and how it relates to other calmodulin-like proteins was unresolved; proximity biotinylation placed MLC7 with MyoH and CaM1–CaM3 and revealed that CaM stability/distribution depends on the MyoH–MLC7 complex.","evidence":"BirA proximity biotinylation with CaM1/2/3, CRISPR/Cas9 editing, auxin-induced degron depletion of MyoH, and super-resolution microscopy in T. gondii","pmids":["28475612"],"confidence":"Medium","gaps":["Interaction inferred from biotinylation rather than reciprocal co-IP or reconstitution","MLC7 not directly depleted to test its role in CaM interdependence","Stoichiometry and architecture of the MyoH–MLC7–CaM assembly unknown"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":null,"claim":"The intrinsic function of MLC7 as a light chain — whether it regulates MyoH motor activity, Ca2+ responsiveness, or complex assembly — remains uncharacterized, as all evidence to date derives from perturbation of MyoH or the CaMs rather than of MLC7 itself.","evidence":"No direct MLC7 loss-of-function or biochemical study reported in the timeline","pmids":[],"confidence":"Low","gaps":["No direct MLC7 knockout/knockdown phenotype","No structural model of the MyoH–MLC7 interface","No test of whether MLC7 confers Ca2+ or calmodulin-dependent regulation"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["MyoH (class XIV myosin H) motor complex at the conoid"],"partners":["MYOH (CLASS XIV MYOSIN H)","CAM1","CAM2","CAM3"],"other_free_text":["MLC7 is a calmodulin/CaM-domain-containing myosin light chain, one of six such candidate light chains in the T. gondii myosin repertoire [#2].","The MyoH tail carries three alpha-tubulin suppressor domains that anchor the motor complex, including MLC7, to the conoid [#0].","Disruption of MyoH degrades CaM3 or redistributes CaM1/CaM2, indicating interdependence between conoid calmodulin-like proteins and the MyoH-MLC7 complex [#1]."]},"strain_conflicts":[]},"prefetch_data":{},"corpus_meta":[{"pmid":"28475612","id":"PMC_28475612","title":"Calmodulin-like proteins localized to the conoid regulate motility and cell invasion by Toxoplasma gondii.","date":"2017","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/28475612","citation_count":84,"is_preprint":false},{"pmid":"26760042","id":"PMC_26760042","title":"The Conoid Associated Motor MyoH Is Indispensable for Toxoplasma gondii Entry and Exit from Host Cells.","date":"2016","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/26760042","citation_count":75,"is_preprint":false},{"pmid":"21143563","id":"PMC_21143563","title":"Unusual anchor of a motor complex (MyoD-MLC2) to the plasma membrane of Toxoplasma gondii.","date":"2011","source":"Traffic (Copenhagen, Denmark)","url":"https://pubmed.ncbi.nlm.nih.gov/21143563","citation_count":28,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":3761,"output_tokens":967,"usd":0.012894,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":5793,"output_tokens":2207,"usd":0.04207,"stage2_stop_reason":"end_turn"},"total_usd":0.054964,"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\": 2016,\n      \"finding\": \"MLC7 was identified as a myosin light chain associated with MyoH (class XIV myosin H) at the conoid of Toxoplasma gondii; MyoH and its associated light chains (including MLC7) are required for parasite motility, invasion, and egress from host cells, and the 3 alpha-tubulin suppressor domains in the MyoH tail anchor this motor complex to the conoid.\",\n      \"method\": \"Conditional disruption of MyoH, subcellular localization, phenotypic analysis of motility/invasion/egress\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — conditional KO with defined cellular phenotype and localization; MLC7 identified as MyoH light chain but mechanistic characterization of MLC7 itself is limited to its association with MyoH\",\n      \"pmids\": [\"26760042\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"BirA-based proximity biotinylation using calmodulin-like proteins (CaM1, CaM2, CaM3) labeled apical proteins including MyoH and its light chain MLC7 at the conoid, suggesting MLC7 is part of the apical MyoH motor complex; disruption of MyoH led to degradation of CaM3 or redistribution of CaM1/CaM2, indicating interdependence between conoid CaMs and the MyoH-MLC7 complex.\",\n      \"method\": \"BirA proximity biotinylation, CRISPR/Cas9-mediated gene editing, auxin-induced degron (AID) system, super-resolution microscopy\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — proximity biotinylation identifies MLC7 as a MyoH-associated protein; interaction is inferred from biotinylation data rather than direct co-IP or reconstitution\",\n      \"pmids\": [\"28475612\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"A survey of calmodulin-like proteins in Apicomplexa identified six putative myosin light chains in T. gondii including MLC7; their subcellular localizations were determined, establishing that MLC7 is one of several CaM-domain-containing light chains in the T. gondii myosin repertoire.\",\n      \"method\": \"Subcellular localization by fluorescence microscopy, bioinformatic identification of CaM-like proteins\",\n      \"journal\": \"Traffic (Copenhagen, Denmark)\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — MLC7 identified in a repertoire survey with localization data; no direct functional characterization of MLC7 itself reported\",\n      \"pmids\": [\"21143563\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"MLC7 is a calmodulin-like myosin light chain that associates with class XIV myosin H (MyoH) at the conoid of Toxoplasma gondii, where it forms part of a motor complex required for parasite motility, invasion, and egress from host cells, and is also in proximity to conoid-localized calmodulin-like proteins (CaM1–3) that functionally depend on MyoH integrity.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MLC7 is a calmodulin-like myosin light chain of Toxoplasma gondii that operates as a component of the apical class XIV myosin H (MyoH) motor complex at the conoid, where this motor drives parasite motility, host-cell invasion, and egress [#0]. MLC7 associates with MyoH, whose tail carries three alpha-tubulin suppressor domains that anchor the motor complex to the conoid [#0], and proximity-biotinylation places MLC7 together with MyoH and the conoid calmodulin-like proteins CaM1\\u2013CaM3, whose stability and distribution depend on an intact MyoH\\u2013MLC7 complex [#1]. MLC7 is one of several CaM-domain light chains in the parasite's myosin repertoire [#2]. Beyond its assignment to the MyoH motor complex and its conoid localization, no direct biochemical or structural characterization of MLC7 itself has been reported in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2011,\n      \"claim\": \"Before any functional assignment, it was unknown which calmodulin-like proteins served as myosin light chains in Toxoplasma; a repertoire survey established MLC7 as one of six CaM-domain-containing candidate light chains with a defined subcellular localization.\",\n      \"evidence\": \"Bioinformatic identification of CaM-like proteins with fluorescence-microscopy localization in T. gondii\",\n      \"pmids\": [\"21143563\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No direct functional characterization of MLC7 itself\", \"Cognate myosin partner not defined at this stage\", \"No demonstration of light-chain activity\"],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"It was unknown which myosin MLC7 partners with and what cellular process that motor serves; conditional disruption of MyoH showed MLC7 is a MyoH-associated light chain of a conoid motor complex required for motility, invasion, and egress.\",\n      \"evidence\": \"Conditional disruption of MyoH with subcellular localization and phenotypic analysis of motility/invasion/egress in T. gondii\",\n      \"pmids\": [\"26760042\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"MLC7's own contribution not tested by direct MLC7 loss-of-function\", \"Direct MLC7\\u2013MyoH binding not biochemically reconstituted\", \"Role of MLC7 in motor mechanochemistry not defined\"],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Whether MLC7 sits within a broader conoid apical complex and how it relates to other calmodulin-like proteins was unresolved; proximity biotinylation placed MLC7 with MyoH and CaM1\\u2013CaM3 and revealed that CaM stability/distribution depends on the MyoH\\u2013MLC7 complex.\",\n      \"evidence\": \"BirA proximity biotinylation with CaM1/2/3, CRISPR/Cas9 editing, auxin-induced degron depletion of MyoH, and super-resolution microscopy in T. gondii\",\n      \"pmids\": [\"28475612\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Interaction inferred from biotinylation rather than reciprocal co-IP or reconstitution\", \"MLC7 not directly depleted to test its role in CaM interdependence\", \"Stoichiometry and architecture of the MyoH\\u2013MLC7\\u2013CaM assembly unknown\"],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The intrinsic function of MLC7 as a light chain \\u2014 whether it regulates MyoH motor activity, Ca2+ responsiveness, or complex assembly \\u2014 remains uncharacterized, as all evidence to date derives from perturbation of MyoH or the CaMs rather than of MLC7 itself.\",\n      \"evidence\": \"No direct MLC7 loss-of-function or biochemical study reported in the timeline\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No direct MLC7 knockout/knockdown phenotype\", \"No structural model of the MyoH\\u2013MLC7 interface\", \"No test of whether MLC7 confers Ca2+ or calmodulin-dependent regulation\"],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0000146\", \"supporting_discovery_ids\": [0], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]},\n      {\"term_id\": \"GO:0005516\", \"supporting_discovery_ids\": [2], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0020009\", \"supporting_discovery_ids\": [0, 1, 2], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0052126\", \"supporting_discovery_ids\": [0], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"complexes\": [\"MyoH (class XIV myosin H) motor complex at the conoid\"],\n    \"partners\": [\"MyoH (class XIV myosin H)\", \"CaM1\", \"CaM2\", \"CaM3\"],\n    \"other_free_text\": [\n      \"MLC7 is a calmodulin/CaM-domain-containing myosin light chain, one of six such candidate light chains in the T. gondii myosin repertoire [#2].\",\n      \"The MyoH tail carries three alpha-tubulin suppressor domains that anchor the motor complex, including MLC7, to the conoid [#0].\",\n      \"Disruption of MyoH degrades CaM3 or redistributes CaM1/CaM2, indicating interdependence between conoid calmodulin-like proteins and the MyoH-MLC7 complex [#1].\"\n    ]\n  },\n  \"strain_conflicts\": []\n}","audit_flag":null,"strains":[{"strain":"ME49","gene_id":"TGME49_315780","name":"MLC7","product":"myosin light chain MLC7","uniprot_acc":"A0A125YT29","chromosome":"TGME49_chrXI","start_pos":4979401},{"strain":"GT1","gene_id":"TGGT1_315780","name":null,"product":"putative myosin regulatory light chain","uniprot_acc":null,"chromosome":"TGGT1_chrXI","start_pos":4923626},{"strain":"RH88","gene_id":"TGRH88_054640","name":null,"product":"putative myosin regulatory light chain","uniprot_acc":null,"chromosome":"CM023092","start_pos":5045589},{"strain":"VEG","gene_id":"TGVEG_315780","name":null,"product":"putative myosin regulatory light chain","uniprot_acc":"B9PJ81","chromosome":"TGVEG_chrXI","start_pos":5002128}]}