{"gene":"TG_315770","gene_symbol":"CYP450mt","run_date":"2026-09-08T15:15:13","timeline":{"discoveries":[{"year":2023,"finding":"TgCYP450mt (a type I cytochrome P450 oxidase) localizes to the mitochondrion of Toxoplasma gondii, as demonstrated by direct localization experiments.","method":"Subcellular localization (direct imaging/fractionation)","journal":"PLoS pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization experiment in a single lab with supporting genetic and metabolomic data","pmids":["37651449"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2023,"finding":"TgCYP450mt physically interacts with TgMAPR (a MAPR family heme-binding protein with a cytochrome b5 domain) in situ, as demonstrated by proximity ligation assays, analogous to the mammalian mitochondrial steroidogenesis system.","method":"In situ proximity ligation assay","journal":"PLoS pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — proximity ligation assay in a single lab, single method for the interaction","pmids":["37651449"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2023,"finding":"TgCYP450mt is essential for Toxoplasma viability; genetic ablation of cyp450mt is not tolerated, and a conditional knockout (iΔTgCYP450mt) shows growth impairment in cultured cells and reduced steroid metabolite levels, establishing its role in parasite steroidogenesis.","method":"Conditional knockout (iΔTgCYP450mt), growth assays, metabolomics (LC-MS)","journal":"PLoS pathogens","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional KO with specific phenotypic readouts (growth, virulence, metabolomics) using multiple orthogonal methods in a single rigorous study","pmids":["37651449"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2023,"finding":"TgCYP450mt is required for synthesis of steroid metabolites (hydroxypregnenolone species, deoxycorticosterone, dehydroepiandrosterone) in Toxoplasma, as iΔTgCYP450mt mutants have reduced levels of these steroids detected by LC-MS targeted lipidomics.","method":"LC-MS targeted lipidomics/metabolomics on conditional knockout parasites","journal":"PLoS pathogens","confidence":"High","confidence_rationale":"Tier 1 / Moderate — direct metabolomic measurement in a loss-of-function strain, single lab but with rigorous LC-MS methodology","pmids":["37651449"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2023,"finding":"Conditional loss of TgCYP450mt results in reduced virulence in mice, establishing that the mitochondrial steroidogenic function of TgCYP450mt contributes to parasite pathogenesis in vivo.","method":"Mouse virulence assay with conditional knockout parasites","journal":"PLoS pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo virulence assay with conditional KO, single lab","pmids":["37651449"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"current_model":"TgCYP450mt is a mitochondrion-localized, essential type I cytochrome P450 oxidase in Toxoplasma gondii that physically interacts with the heme-binding partner TgMAPR (via a cytochrome b5 domain) and is required for parasite steroidogenesis—producing hydroxypregnenolone species, deoxycorticosterone, and dehydroepiandrosterone from cholesterol—with its loss causing growth impairment, reduced steroid levels, and attenuated virulence in mice."},"narrative":{"mechanistic_narrative":"TgCYP450mt is a mitochondrion-localized, type I cytochrome P450 oxidase in Toxoplasma gondii that drives parasite steroidogenesis and is essential for viability [PMID:37651449]. It physically associates in situ with TgMAPR, a MAPR-family heme-binding protein bearing a cytochrome b5 domain, forming a partnership analogous to the mammalian mitochondrial steroidogenic system [PMID:37651449]. Functionally, TgCYP450mt is required for the conversion of steroid precursors into hydroxypregnenolone species, deoxycorticosterone, and dehydroepiandrosterone, as conditional knockout (iΔTgCYP450mt) parasites show markedly reduced levels of these metabolites [PMID:37651449]. Loss of this steroidogenic function impairs parasite growth in culture and attenuates virulence in mice, linking mitochondrial steroid biosynthesis to pathogenesis [PMID:37651449]. Beyond these findings, the enzyme's precise catalytic reactions, substrate-binding determinants, and structural organization have not been characterized in the available corpus.","teleology":[{"year":2023,"claim":"Establishing where the enzyme acts and what it partners with was needed to place TgCYP450mt in a specific biosynthetic context; localization and interaction data situated it in the mitochondrion alongside a heme-binding cytochrome b5-domain partner.","evidence":"Direct subcellular localization plus in situ proximity ligation assay with TgMAPR in Toxoplasma gondii","pmids":["37651449"],"confidence":"Medium","gaps":["TgMAPR interaction rests on a single method (proximity ligation) without reciprocal biochemical validation","Stoichiometry and functional consequence of the TgCYP450mt-TgMAPR interaction not resolved","Electron donor/redox partner supplying the P450 not identified"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2023,"claim":"Whether TgCYP450mt was dispensable and what pathway it served were open; conditional ablation combined with metabolomics showed it is essential and required for steroid metabolite production, defining a mitochondrial steroidogenic role.","evidence":"Conditional knockout (iΔTgCYP450mt), growth assays, and LC-MS targeted lipidomics in Toxoplasma gondii","pmids":["37651449"],"confidence":"High","gaps":["Specific enzymatic reactions and direct substrates catalyzed by TgCYP450mt not defined in vitro","Whether reduced steroids are a direct or downstream consequence of ablation not distinguished","No structural or active-site characterization"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2023,"claim":"It was unknown whether the steroidogenic function mattered in vivo; conditional loss reduced virulence in mice, tying mitochondrial steroidogenesis to pathogenesis.","evidence":"Mouse virulence assay with conditional knockout parasites","pmids":["37651449"],"confidence":"Medium","gaps":["Mechanism linking steroid depletion to attenuated virulence not established","Host cell processes affected by parasite-derived steroids not identified"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":null,"claim":"The catalytic mechanism, direct substrates and products, redox partners, and structural basis of TgCYP450mt activity remain undefined.","evidence":"No direct enzymatic or structural characterization present in the corpus","pmids":[],"confidence":"Low","gaps":["No in vitro reconstitution of the P450 reaction","Electron-transfer partner and heme utilization not characterized","No structural model of substrate binding or the TgMAPR complex"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["TgCYP450mt-TgMAPR (cytochrome b5-domain heme-binding partner)"],"partners":["TGMAPR"],"other_free_text":["Essential for Toxoplasma gondii viability; conditional ablation impairs growth and attenuates virulence in mice.","Required for synthesis of hydroxypregnenolone species, deoxycorticosterone, and dehydroepiandrosterone."]},"strain_conflicts":[]},"prefetch_data":{},"corpus_meta":[{"pmid":"37651449","id":"PMC_37651449","title":"Function and regulation of a steroidogenic CYP450 enzyme in the mitochondrion of Toxoplasma gondii.","date":"2023","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/37651449","citation_count":5,"is_preprint":false},{"pmid":"42188900","id":"PMC_42188900","title":"Toxoplasma gondii as a Direct Cause of Reproductive Dysfunction: Dual Threats to Male and Female Fertility.","date":"2026","source":"Veterinary sciences","url":"https://pubmed.ncbi.nlm.nih.gov/42188900","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":3785,"output_tokens":1210,"usd":0.014752,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":6213,"output_tokens":1997,"usd":0.040495,"stage2_stop_reason":"end_turn"},"total_usd":0.055247,"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\": 2023,\n      \"finding\": \"TgCYP450mt (a type I cytochrome P450 oxidase) localizes to the mitochondrion of Toxoplasma gondii, as demonstrated by direct localization experiments.\",\n      \"method\": \"Subcellular localization (direct imaging/fractionation)\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization experiment in a single lab with supporting genetic and metabolomic data\",\n      \"pmids\": [\"37651449\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"TgCYP450mt physically interacts with TgMAPR (a MAPR family heme-binding protein with a cytochrome b5 domain) in situ, as demonstrated by proximity ligation assays, analogous to the mammalian mitochondrial steroidogenesis system.\",\n      \"method\": \"In situ proximity ligation assay\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — proximity ligation assay in a single lab, single method for the interaction\",\n      \"pmids\": [\"37651449\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"TgCYP450mt is essential for Toxoplasma viability; genetic ablation of cyp450mt is not tolerated, and a conditional knockout (iΔTgCYP450mt) shows growth impairment in cultured cells and reduced steroid metabolite levels, establishing its role in parasite steroidogenesis.\",\n      \"method\": \"Conditional knockout (iΔTgCYP450mt), growth assays, metabolomics (LC-MS)\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional KO with specific phenotypic readouts (growth, virulence, metabolomics) using multiple orthogonal methods in a single rigorous study\",\n      \"pmids\": [\"37651449\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"TgCYP450mt is required for synthesis of steroid metabolites (hydroxypregnenolone species, deoxycorticosterone, dehydroepiandrosterone) in Toxoplasma, as iΔTgCYP450mt mutants have reduced levels of these steroids detected by LC-MS targeted lipidomics.\",\n      \"method\": \"LC-MS targeted lipidomics/metabolomics on conditional knockout parasites\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — direct metabolomic measurement in a loss-of-function strain, single lab but with rigorous LC-MS methodology\",\n      \"pmids\": [\"37651449\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Conditional loss of TgCYP450mt results in reduced virulence in mice, establishing that the mitochondrial steroidogenic function of TgCYP450mt contributes to parasite pathogenesis in vivo.\",\n      \"method\": \"Mouse virulence assay with conditional knockout parasites\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo virulence assay with conditional KO, single lab\",\n      \"pmids\": [\"37651449\"],\n      \"is_preprint\": false,\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    }\n  ],\n  \"current_model\": \"TgCYP450mt is a mitochondrion-localized, essential type I cytochrome P450 oxidase in Toxoplasma gondii that physically interacts with the heme-binding partner TgMAPR (via a cytochrome b5 domain) and is required for parasite steroidogenesis—producing hydroxypregnenolone species, deoxycorticosterone, and dehydroepiandrosterone from cholesterol—with its loss causing growth impairment, reduced steroid levels, and attenuated virulence in mice.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"TgCYP450mt is a mitochondrion-localized, type I cytochrome P450 oxidase in Toxoplasma gondii that drives parasite steroidogenesis and is essential for viability [#0, #2]. It physically associates in situ with TgMAPR, a MAPR-family heme-binding protein bearing a cytochrome b5 domain, forming a partnership analogous to the mammalian mitochondrial steroidogenic system [#1]. Functionally, TgCYP450mt is required for the conversion of steroid precursors into hydroxypregnenolone species, deoxycorticosterone, and dehydroepiandrosterone, as conditional knockout (iΔTgCYP450mt) parasites show markedly reduced levels of these metabolites [#3]. Loss of this steroidogenic function impairs parasite growth in culture and attenuates virulence in mice, linking mitochondrial steroid biosynthesis to pathogenesis [#2, #4]. Beyond these findings, the enzyme's precise catalytic reactions, substrate-binding determinants, and structural organization have not been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2023,\n      \"claim\": \"Establishing where the enzyme acts and what it partners with was needed to place TgCYP450mt in a specific biosynthetic context; localization and interaction data situated it in the mitochondrion alongside a heme-binding cytochrome b5-domain partner.\",\n      \"evidence\": \"Direct subcellular localization plus in situ proximity ligation assay with TgMAPR in Toxoplasma gondii\",\n      \"pmids\": [\"37651449\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"TgMAPR interaction rests on a single method (proximity ligation) without reciprocal biochemical validation\",\n        \"Stoichiometry and functional consequence of the TgCYP450mt-TgMAPR interaction not resolved\",\n        \"Electron donor/redox partner supplying the P450 not identified\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Whether TgCYP450mt was dispensable and what pathway it served were open; conditional ablation combined with metabolomics showed it is essential and required for steroid metabolite production, defining a mitochondrial steroidogenic role.\",\n      \"evidence\": \"Conditional knockout (iΔTgCYP450mt), growth assays, and LC-MS targeted lipidomics in Toxoplasma gondii\",\n      \"pmids\": [\"37651449\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Specific enzymatic reactions and direct substrates catalyzed by TgCYP450mt not defined in vitro\",\n        \"Whether reduced steroids are a direct or downstream consequence of ablation not distinguished\",\n        \"No structural or active-site characterization\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"It was unknown whether the steroidogenic function mattered in vivo; conditional loss reduced virulence in mice, tying mitochondrial steroidogenesis to pathogenesis.\",\n      \"evidence\": \"Mouse virulence assay with conditional knockout parasites\",\n      \"pmids\": [\"37651449\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Mechanism linking steroid depletion to attenuated virulence not established\",\n        \"Host cell processes affected by parasite-derived steroids not identified\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The catalytic mechanism, direct substrates and products, redox partners, and structural basis of TgCYP450mt activity remain undefined.\",\n      \"evidence\": \"No direct enzymatic or structural characterization present in the corpus\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No in vitro reconstitution of the P450 reaction\",\n        \"Electron-transfer partner and heme utilization not characterized\",\n        \"No structural model of substrate binding or the TgMAPR complex\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0016705\", \"supporting_discovery_ids\": [0, 3], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]},\n      {\"term_id\": \"GO:0006694\", \"supporting_discovery_ids\": [2, 3], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [0], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0006694\", \"supporting_discovery_ids\": [3], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"complexes\": [\"TgCYP450mt-TgMAPR (cytochrome b5-domain heme-binding partner)\"],\n    \"partners\": [\"TgMAPR\"],\n    \"other_free_text\": [\n      \"Essential for Toxoplasma gondii viability; conditional ablation impairs growth and attenuates virulence in mice.\",\n      \"Required for synthesis of hydroxypregnenolone species, deoxycorticosterone, and dehydroepiandrosterone.\"\n    ]\n  },\n  \"strain_conflicts\": []\n}","audit_flag":null,"strains":[{"strain":"ME49","gene_id":"TGME49_315770","name":"CYP450mt","product":"cytochrome p450","uniprot_acc":"S8EQL7","chromosome":"TGME49_chrXI","start_pos":4968733},{"strain":"GT1","gene_id":"TGGT1_315770","name":null,"product":"cytochrome p450 superfamily protein","uniprot_acc":null,"chromosome":"TGGT1_chrXI","start_pos":4913385},{"strain":"RH88","gene_id":"TGRH88_054630","name":null,"product":"cytochrome p450 superfamily protein","uniprot_acc":null,"chromosome":"CM023092","start_pos":5035348},{"strain":"VEG","gene_id":"TGVEG_315770","name":null,"product":"cytochrome p450 superfamily protein","uniprot_acc":"A0A125YN28","chromosome":"TGVEG_chrXI","start_pos":4991859}]}