{"id":"7c7b0daa-9c1b-580f-bb34-a296193efc8a","stable_key":"27e0c1cf-7726-5164-8b15-27a631584cd0:choline-cept1-pc","predicate":"synthesizes","statement":"CEPT1 can catalyze PC production as well as PE production.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"6d31bb6d-374f-530b-8bf4-cbd34e60e5b9","mechanism_event_label":"A separate terminal enzyme can serve both headgroup pathways.","subject":{"id":"cec694f4-b1a4-5700-b97f-84d7ae8eb672","slug":"cept1","display_name":"Human choline/ethanolamine phosphotransferase 1 / CEPT1","entity_type_key":"protein"},"object":{"id":"2f77ef6d-3ecd-5a80-9ca3-3cbea403d9fc","slug":"phosphatidylcholine","display_name":"Phosphatidylcholine","entity_type_key":"lipid"},"evidence_count":1,"mechanism_event":{"id":"6d31bb6d-374f-530b-8bf4-cbd34e60e5b9","stable_key":"27e0c1cf-7726-5164-8b15-27a631584cd0:choline-cept1-pc-event","event_type":"biochemical_relationship","label":"A separate terminal enzyme can serve both headgroup pathways.","description":"CEPT1 can catalyze PC production as well as PE production.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"e1f22bfd-771d-5405-b2d4-ff5f4ae4d95f","slug":"cdp-choline","display_name":"CDP-choline","entity_type_key":"small_molecule"},"role":"activated_headgroup","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"cec694f4-b1a4-5700-b97f-84d7ae8eb672","slug":"cept1","display_name":"Human choline/ethanolamine phosphotransferase 1 / CEPT1","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"2f77ef6d-3ecd-5a80-9ca3-3cbea403d9fc","slug":"phosphatidylcholine","display_name":"Phosphatidylcholine","entity_type_key":"lipid"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/choline-research/40435706.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"d08b2ce68e8731e88e1204dc1b09d1301020452752a630a880ec3a2cdb0f2351\", \"start_char\": 0, \"end_char\": 1339, \"text_sha256\": \"d08b2ce68e8731e88e1204dc1b09d1301020452752a630a880ec3a2cdb0f2351\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human CHPT1 cryo-EM, sequence analysis and biochemical characterization","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"CDP-choline/CDP-ethanolamine substrate selectivity","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Human CHPT1 and CEPT1 remain separate. 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(2025). https://pubmed.ncbi.nlm.nih.gov/40435706/ DOI: 10.1016/j.bbrc.2025.152082","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Membrane phospholipid synthesis","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"51bc41c0-8beb-5a44-854f-de5d73d5ac55","evidence_kind":"source_excerpt","locator":"Lines 776-787","start_line":776,"end_line":787,"excerpt":"### choline-cept1-pc\nCEPT1 can catalyze PC production as well as PE production.\nCondition category: normal\nnutrient_topic: Choline research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: A separate terminal enzyme can serve both headgroup pathways.\norganism: Human proteins; evolutionary comparisons explicitly separate\ntissue_or_cell_type: Membrane phospholipid synthesis\nexperimental_model: Human CHPT1 cryo-EM, sequence analysis and biochemical characterization\nlimitations: Human CHPT1 and CEPT1 remain separate. Evolutionary suggestions about oviparous species are not asserted as human bifunctionality.\nexposure: CDP-choline/CDP-ethanolamine substrate selectivity\nevidence_span: {\"source_cache\": \"artifacts/choline-research/40435706.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"d08b2ce68e8731e88e1204dc1b09d1301020452752a630a880ec3a2cdb0f2351\", \"start_char\": 0, \"end_char\": 1339, \"text_sha256\": \"d08b2ce68e8731e88e1204dc1b09d1301020452752a630a880ec3a2cdb0f2351\"}\n[choline-p40435706] Structural basis for substrate selectivity and evolutionary insights into human choline phosphotransferase 1. 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