{"id":"0220b398-5d06-599b-b508-a4eb95dfb551","stable_key":"09b23d0d-35e2-51ff-b1aa-b4f9227e4fa2:isoleucine-acat1-split","predicate":"cleaves","statement":"Human mitochondrial ACAT1/T2 degraded 2-methylacetoacetyl-CoA by CoA-dependent thiolysis, yielding the isoleucine-branch acetyl-CoA and propionyl-CoA products.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"39b524bf-58f0-5ce6-9a09-df6958ec74d6","mechanism_event_label":"One carbon skeleton feeds both an acetyl branch and a propionyl branch.","subject":{"id":"4e3ca267-b01e-550b-aa8e-4db62e54102d","slug":"acat1","display_name":"Mitochondrial acetyl-CoA acetyltransferase / ACAT1","entity_type_key":"protein"},"object":{"id":"2c795364-e2ff-5782-8270-81e153e92c9d","slug":"2-methylacetoacetyl-coa","display_name":"2-Methylacetoacetyl-CoA","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"39b524bf-58f0-5ce6-9a09-df6958ec74d6","stable_key":"09b23d0d-35e2-51ff-b1aa-b4f9227e4fa2:isoleucine-acat1-split-event","event_type":"observed_relationship","label":"One carbon skeleton feeds both an acetyl branch and a propionyl branch.","description":"Human mitochondrial ACAT1/T2 degraded 2-methylacetoacetyl-CoA by CoA-dependent thiolysis, yielding the isoleucine-branch acetyl-CoA and propionyl-CoA products.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"4e3ca267-b01e-550b-aa8e-4db62e54102d","slug":"acat1","display_name":"Mitochondrial acetyl-CoA acetyltransferase / ACAT1","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"2c795364-e2ff-5782-8270-81e153e92c9d","slug":"2-methylacetoacetyl-coa","display_name":"2-Methylacetoacetyl-CoA","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"c85b327e-f132-5d9a-8e4b-c2976fcc0373","slug":"isoleucine","display_name":"L-Isoleucine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"4faa6456-aff8-59eb-9e3f-3326a436e401","slug":"coenzyme-a","display_name":"Coenzyme A","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"b7ed6e4c-e560-5cee-b68f-895f21862e6f","slug":"acetyl-coa","display_name":"Acetyl-CoA","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""},{"entity":{"id":"69ac0570-94d8-59d8-85ef-7f67cf302d16","slug":"propionyl-coa","display_name":"Propionyl-CoA","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":5,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Purified human T2 structural/kinetic study; established product chemistry.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"ACAT1 here is acetyl-CoA acetyltransferase, not the cholesterol-esterifying SOAT1 enzyme sometimes called ACAT.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Isoleucine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"isoleucine","display_name":"L-Isoleucine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"One carbon skeleton feeds both an acetyl branch and a propionyl branch.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Crystallographic and kinetic studies of human mitochondrial acetoacetyl-CoA thiolase: the importance of potassium and chloride ions for its structure and function. · 2007 · https://pubmed.ncbi.nlm.nih.gov/17371050/ · DOI 10.1021/bi6026192","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"8cf6217a-6c4c-5082-b8fa-8ba8be6227b9","evidence_kind":"source_excerpt","locator":"Lines 226-232","start_line":226,"end_line":232,"excerpt":"## isoleucine-acat1-split\nOne carbon skeleton feeds both an acetyl branch and a propionyl branch.\nHuman mitochondrial ACAT1/T2 degraded 2-methylacetoacetyl-CoA by CoA-dependent thiolysis, yielding the isoleucine-branch acetyl-CoA and propionyl-CoA products.\nModel: Purified human T2 structural/kinetic study; established product chemistry.\nLimitations: ACAT1 here is acetyl-CoA acetyltransferase, not the cholesterol-esterifying SOAT1 enzyme sometimes called ACAT.\nEvidence access: Primary abstract\nCrystallographic and kinetic studies of human mitochondrial acetoacetyl-CoA thiolase: the importance of potassium and chloride ions for its structure and function. · 2007 · https://pubmed.ncbi.nlm.nih.gov/17371050/ · DOI 10.1021/bi6026192","model_system":"Purified human T2 structural/kinetic study; established product chemistry.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access and experimental limitations specified.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"4b00f118-00fd-5cef-be97-13125eb958e9","stable_key":"import-09b23d0d-35e2-51ff-b1aa-b4f9227e4fa2","title":"L-Isoleucine: transport, translation, catabolism and cross-nutrient mechanisms (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; 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