{"id":"f86f1207-5c09-52c0-aa1f-e5b61908ba74","stable_key":"27e0c1cf-7726-5164-8b15-27a631584cd0:choline-pemt-sam","predicate":"donates_methyl_groups_via","statement":"SAM supplies the methyl groups for each of the three PEMT-catalyzed transfers.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"82d183e7-9abb-5f47-9496-f608d4c6621f","mechanism_event_label":"Membrane PC synthesis and the methyl-donor pool are connected.","subject":{"id":"825f2da2-01bc-5874-a3c6-64f5ac867db5","slug":"s-adenosylmethionine","display_name":"S-Adenosyl-L-methionine","entity_type_key":"small_molecule"},"object":{"id":"a5acc0c5-f4ed-5b32-abfa-f9b27c025356","slug":"pemt","display_name":"Human phosphatidylethanolamine N-methyltransferase / PEMT","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"82d183e7-9abb-5f47-9496-f608d4c6621f","stable_key":"27e0c1cf-7726-5164-8b15-27a631584cd0:choline-pemt-sam-event","event_type":"biochemical_relationship","label":"Membrane PC synthesis and the methyl-donor pool are connected.","description":"SAM supplies the methyl groups for each of the three PEMT-catalyzed transfers.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"be4a52f4-f31c-59b7-b0da-4178fbb069c8","slug":"phosphatidylethanolamine","display_name":"Phosphatidylethanolamine","entity_type_key":"lipid"},"role":"acceptor","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"2f77ef6d-3ecd-5a80-9ca3-3cbea403d9fc","slug":"phosphatidylcholine","display_name":"Phosphatidylcholine","entity_type_key":"lipid"},"role":"final_product","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"825f2da2-01bc-5874-a3c6-64f5ac867db5","slug":"s-adenosylmethionine","display_name":"S-Adenosyl-L-methionine","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"a5acc0c5-f4ed-5b32-abfa-f9b27c025356","slug":"pemt","display_name":"Human phosphatidylethanolamine N-methyltransferase / PEMT","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/choline-research/12431977.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"7c299a547408772f2f24bdd77f2f22dc8ea9e5aaf8179150f2d8b59c9713306a\", \"start_char\": 0, \"end_char\": 1380, \"text_sha256\": \"7c299a547408772f2f24bdd77f2f22dc8ea9e5aaf8179150f2d8b59c9713306a\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human liver fractionation and recombinant PEMT membrane-topology experiments","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Protein cleavage mapping and methyltransferase localization","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Three methyl transfers make a choline-containing phospholipid; PEMT does not directly synthesize free choline from nothing.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Choline research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"choline","display_name":"Choline","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Human enzyme","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Membrane PC synthesis and the methyl-donor pool are connected.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[choline-p12431977] Membrane topography of human phosphatidylethanolamine N-methyltransferase. (2003). https://pubmed.ncbi.nlm.nih.gov/12431977/ DOI: 10.1074/jbc.m210904200","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"ER and mitochondria-associated membranes","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"53e3d1fd-dbdd-5641-9155-c75c5ece6983","evidence_kind":"source_excerpt","locator":"Lines 815-826","start_line":815,"end_line":826,"excerpt":"### choline-pemt-sam\nSAM supplies the methyl groups for each of the three PEMT-catalyzed transfers.\nCondition category: normal\nnutrient_topic: Choline research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Membrane PC synthesis and the methyl-donor pool are connected.\norganism: Human enzyme\ntissue_or_cell_type: ER and mitochondria-associated membranes\nexperimental_model: Human liver fractionation and recombinant PEMT membrane-topology experiments\nlimitations: Three methyl transfers make a choline-containing phospholipid; PEMT does not directly synthesize free choline from nothing.\nexposure: Protein cleavage mapping and methyltransferase localization\nevidence_span: {\"source_cache\": \"artifacts/choline-research/12431977.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"7c299a547408772f2f24bdd77f2f22dc8ea9e5aaf8179150f2d8b59c9713306a\", \"start_char\": 0, \"end_char\": 1380, \"text_sha256\": \"7c299a547408772f2f24bdd77f2f22dc8ea9e5aaf8179150f2d8b59c9713306a\"}\n[choline-p12431977] Membrane topography of human phosphatidylethanolamine N-methyltransferase. 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