{"gene":"TG_297470","gene_symbol":"MLC2","run_date":"2026-09-08T15:15:12","timeline":{"discoveries":[{"year":2011,"finding":"MLC2 is associated with myosin D (MyoD) via its calmodulin (CaM)-like domain, forming a MyoD-MLC2 motor complex anchored to the plasma membrane of T. gondii via its N-terminal extension.","method":"Subcellular localization experiments, molecular modeling, identification of protein-protein association","journal":"Traffic (Copenhagen, Denmark)","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — subcellular localization and complex identification in single study; molecular modeling supports but does not experimentally validate compact complex structure; palmitoylation as anchor is inferred, not directly demonstrated","pmids":["21143563"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2011,"finding":"MLC2 is restricted to coccidians (not found in other apicomplexans such as Plasmodium), distinguishing it from other calmodulin-like myosin light chains in the phylum.","method":"Comparative genomic/bioinformatic survey of calmodulin-like proteins across Apicomplexans combined with experimental localization","journal":"Traffic (Copenhagen, Denmark)","confidence":"Low","confidence_rationale":"Tier 4 / Weak — coccidian-restricted distribution based on sequence survey; no functional experiment directly tests mechanistic consequence of this restriction","pmids":["21143563"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2011,"finding":"Anchorage of MLC2 to the plasma membrane is likely governed by palmitoylation of its N-terminal extension.","method":"Molecular modeling and sequence analysis (palmitoylation sites predicted); direct biochemical demonstration not reported in abstract","journal":"Traffic (Copenhagen, Denmark)","confidence":"Low","confidence_rationale":"Tier 4 / Weak — palmitoylation as mechanism is inferred from sequence/modeling, not experimentally demonstrated in the abstract","pmids":["21143563"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"current_model":"MLC2 is a coccidian-specific myosin light chain that associates with myosin D (MyoD) through its calmodulin-like domain and is anchored to the plasma membrane of Toxoplasma gondii via its N-terminal extension, likely through palmitoylation, forming a compact MyoD-MLC2 motor complex at the parasite plasma membrane."},"narrative":{"mechanistic_narrative":"MLC2 is a coccidian-specific myosin light chain of Toxoplasma gondii that functions as a regulatory subunit of a plasma-membrane-anchored motor complex [PMID:21143563]. It associates with myosin D (MyoD) through its calmodulin-like domain, forming a MyoD-MLC2 motor complex, and is targeted to the parasite plasma membrane by its N-terminal extension [PMID:21143563]. Beyond this association and membrane-anchoring role, the enzymatic mechanism and functional consequences of the complex have not been characterized in the available corpus.","teleology":[{"year":2011,"claim":"Establishing whether an unassigned calmodulin-like protein partners with a specific myosin defined MLC2 as the light chain of a discrete MyoD motor complex at the parasite plasma membrane.","evidence":"subcellular localization, protein-protein association, and molecular modeling in T. gondii","pmids":["21143563"],"confidence":"Medium","gaps":["the compact complex architecture rests on modeling, not an experimentally solved structure","the functional role of the MyoD-MLC2 complex in parasite biology (e.g. motility, invasion) was not tested"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2011,"claim":"Comparative genomics addressed how phylogenetically widespread this light chain is, showing MLC2 is restricted to coccidians and absent from other apicomplexans such as Plasmodium.","evidence":"bioinformatic survey of calmodulin-like proteins across Apicomplexa combined with experimental localization","pmids":["21143563"],"confidence":"Low","gaps":["coccidian restriction is a sequence-based inference; no functional experiment tests the mechanistic consequence of this lineage restriction"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2011,"claim":"To explain how MLC2 reaches the plasma membrane, sequence/modeling analysis identified palmitoylation of its N-terminal extension as the likely membrane anchor.","evidence":"sequence analysis and molecular modeling predicting palmitoylation sites in T. gondii","pmids":["21143563"],"confidence":"Low","gaps":["palmitoylation is inferred from prediction; direct biochemical demonstration of lipid modification was not reported","the palmitoyltransferase and whether the modification is required for membrane targeting are unknown"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":null,"claim":"The catalytic/mechanical output of the MyoD-MLC2 complex and its role in parasite motility, invasion, or replication remain undefined.","evidence":"no functional or structural characterization in the available corpus","pmids":[],"confidence":"Low","gaps":["no genetic knockout or knockdown phenotype","no direct demonstration of palmitoylation or its functional requirement","no experimentally solved complex structure"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["MyoD-MLC2 motor complex"],"partners":["MYOD (MYOSIN D)"],"other_free_text":["Coccidian-restricted calmodulin-like myosin light chain; associates with MyoD via its calmodulin-like domain [#0, #1].","N-terminal extension mediates plasma-membrane anchoring, predicted to occur through palmitoylation [#2]."]},"strain_conflicts":[]},"prefetch_data":{},"corpus_meta":[{"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":2805,"output_tokens":757,"usd":0.009885,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":5564,"output_tokens":1559,"usd":0.033397,"stage2_stop_reason":"end_turn"},"total_usd":0.043282,"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\": 2011,\n      \"finding\": \"MLC2 is associated with myosin D (MyoD) via its calmodulin (CaM)-like domain, forming a MyoD-MLC2 motor complex anchored to the plasma membrane of T. gondii via its N-terminal extension.\",\n      \"method\": \"Subcellular localization experiments, molecular modeling, identification of protein-protein association\",\n      \"journal\": \"Traffic (Copenhagen, Denmark)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — subcellular localization and complex identification in single study; molecular modeling supports but does not experimentally validate compact complex structure; palmitoylation as anchor is inferred, not directly demonstrated\",\n      \"pmids\": [\"21143563\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"MLC2 is restricted to coccidians (not found in other apicomplexans such as Plasmodium), distinguishing it from other calmodulin-like myosin light chains in the phylum.\",\n      \"method\": \"Comparative genomic/bioinformatic survey of calmodulin-like proteins across Apicomplexans combined with experimental localization\",\n      \"journal\": \"Traffic (Copenhagen, Denmark)\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — coccidian-restricted distribution based on sequence survey; no functional experiment directly tests mechanistic consequence of this restriction\",\n      \"pmids\": [\"21143563\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Anchorage of MLC2 to the plasma membrane is likely governed by palmitoylation of its N-terminal extension.\",\n      \"method\": \"Molecular modeling and sequence analysis (palmitoylation sites predicted); direct biochemical demonstration not reported in abstract\",\n      \"journal\": \"Traffic (Copenhagen, Denmark)\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — palmitoylation as mechanism is inferred from sequence/modeling, not experimentally demonstrated in the abstract\",\n      \"pmids\": [\"21143563\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}\n      ]\n    }\n  ],\n  \"current_model\": \"MLC2 is a coccidian-specific myosin light chain that associates with myosin D (MyoD) through its calmodulin-like domain and is anchored to the plasma membrane of Toxoplasma gondii via its N-terminal extension, likely through palmitoylation, forming a compact MyoD-MLC2 motor complex at the parasite plasma membrane.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"MLC2 is a coccidian-specific myosin light chain of Toxoplasma gondii that functions as a regulatory subunit of a plasma-membrane-anchored motor complex [#0]. It associates with myosin D (MyoD) through its calmodulin-like domain, forming a MyoD-MLC2 motor complex, and is targeted to the parasite plasma membrane by its N-terminal extension [#0]. Beyond this association and membrane-anchoring role, the enzymatic mechanism and functional consequences of the complex have not been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2011,\n      \"claim\": \"Establishing whether an unassigned calmodulin-like protein partners with a specific myosin defined MLC2 as the light chain of a discrete MyoD motor complex at the parasite plasma membrane.\",\n      \"evidence\": \"subcellular localization, protein-protein association, and molecular modeling in T. gondii\",\n      \"pmids\": [\"21143563\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"the compact complex architecture rests on modeling, not an experimentally solved structure\",\n        \"the functional role of the MyoD-MLC2 complex in parasite biology (e.g. motility, invasion) was not tested\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Comparative genomics addressed how phylogenetically widespread this light chain is, showing MLC2 is restricted to coccidians and absent from other apicomplexans such as Plasmodium.\",\n      \"evidence\": \"bioinformatic survey of calmodulin-like proteins across Apicomplexa combined with experimental localization\",\n      \"pmids\": [\"21143563\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"coccidian restriction is a sequence-based inference; no functional experiment tests the mechanistic consequence of this lineage restriction\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"To explain how MLC2 reaches the plasma membrane, sequence/modeling analysis identified palmitoylation of its N-terminal extension as the likely membrane anchor.\",\n      \"evidence\": \"sequence analysis and molecular modeling predicting palmitoylation sites in T. gondii\",\n      \"pmids\": [\"21143563\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"palmitoylation is inferred from prediction; direct biochemical demonstration of lipid modification was not reported\",\n        \"the palmitoyltransferase and whether the modification is required for membrane targeting are unknown\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The catalytic/mechanical output of the MyoD-MLC2 complex and its role in parasite motility, invasion, or replication remain undefined.\",\n      \"evidence\": \"no functional or structural characterization in the available corpus\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"no genetic knockout or knockdown phenotype\",\n        \"no direct demonstration of palmitoylation or its functional requirement\",\n        \"no experimentally solved complex structure\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0017022\", \"supporting_discovery_ids\": [0], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 2], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"pathway\": [],\n    \"complexes\": [\"MyoD-MLC2 motor complex\"],\n    \"partners\": [\"MyoD (myosin D)\"],\n    \"other_free_text\": [\n      \"Coccidian-restricted calmodulin-like myosin light chain; associates with MyoD via its calmodulin-like domain [#0, #1].\",\n      \"N-terminal extension mediates plasma-membrane anchoring, predicted to occur through palmitoylation [#2].\"\n    ]\n  },\n  \"strain_conflicts\": []\n}\n```","audit_flag":null,"strains":[{"strain":"ME49","gene_id":"TGME49_297470","name":"MLC2","product":"myosin light chain MLC2","uniprot_acc":"S8FBF7","chromosome":"TGME49_chrII","start_pos":1804059},{"strain":"GT1","gene_id":"TGGT1_297470","name":null,"product":"putative myosin light chain 2","uniprot_acc":null,"chromosome":"TGGT1_chrII","start_pos":1781267},{"strain":"RH88","gene_id":"TGRH88_002330","name":null,"product":"putative myosin light chain 2","uniprot_acc":null,"chromosome":"CM023083","start_pos":1977930},{"strain":"VEG","gene_id":"TGVEG_297470","name":null,"product":"putative myosin light chain 2","uniprot_acc":"V5B269","chromosome":"TGVEG_chrII","start_pos":1814877}]}