{"id":"3cd08fc8-ba3e-59cb-9239-e2f4b2a62830","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:l929-b12-lowers-methylmalonyl-pool","predicate":"supplementation-reduces","statement":"Adding 2.5 micromolar B12 during ECHDC1-knockout L929 adipocyte differentiation lowered whole-cell methylmalonyl-CoA approximately 20-fold.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"6e2bf79f-7a69-52cd-9eb3-2979689b51f0","mechanism_event_label":"B12 addition sharply lowered this measured precursor pool in cultured mouse adipocytes. The cells had ECHDC1 deleted.","subject":{"id":"b6d9b937-895d-5e0a-8cc5-0454a0b7d373","slug":"vitamin-b12","display_name":"Vitamin B12 (cobalamins)","entity_type_key":"chemical_species"},"object":{"id":"068134fc-5f79-50e7-b3bc-09af60b1607c","slug":"methylmalonyl-coa-total-cell-pool","display_name":"Whole-cell methylmalonyl-CoA pool","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"6e2bf79f-7a69-52cd-9eb3-2979689b51f0","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:l929-b12-lowers-methylmalonyl-pool-event","event_type":"biochemical_relationship","label":"B12 addition sharply lowered this measured precursor pool in cultured mouse adipocytes. The cells had ECHDC1 deleted.","description":"Adding 2.5 micromolar B12 during ECHDC1-knockout L929 adipocyte differentiation lowered whole-cell methylmalonyl-CoA approximately 20-fold.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"b6d9b937-895d-5e0a-8cc5-0454a0b7d373","slug":"vitamin-b12","display_name":"Vitamin B12 (cobalamins)","entity_type_key":"chemical_species"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"068134fc-5f79-50e7-b3bc-09af60b1607c","slug":"methylmalonyl-coa-total-cell-pool","display_name":"Whole-cell methylmalonyl-CoA pool","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"cross_nutrient","value_text":"false","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_location","value_text":"Full text Results: vitamin B12 supplementation; Figure 4g-u","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Differentiating ECHDC1-knockout mouse L929 adipocytes (Figure 4g-u)","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"ECHDC1 knockout; 2.5 micromolar supplementary B12 during differentiation","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Whole-cell LC-MS pools; no compartment or epimer resolution and no direct pathway flux measurement.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-b12","display_name":"Vitamin B12 (cobalamins)","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Mus musculus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"B12 addition sharply lowered this measured precursor pool in cultured mouse adipocytes. The cells had ECHDC1 deleted.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[dewulf-2019-l929-b12] The synthesis of branched-chain fatty acids is limited by enzymatic decarboxylation of ethyl- and methylmalonyl-CoA. (2019). https://pubmed.ncbi.nlm.nih.gov/31416829/ DOI: 10.1042/bcj20190500","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Adipocytes","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"adc9a2f5-96fb-5b09-bfdd-28585f9f59bb","evidence_kind":"source_excerpt","locator":"Lines 1258-1270","start_line":1258,"end_line":1270,"excerpt":"### l929-b12-lowers-methylmalonyl-pool\nAdding 2.5 micromolar B12 during ECHDC1-knockout L929 adipocyte differentiation lowered whole-cell methylmalonyl-CoA approximately 20-fold.\nCondition category: machinery_impairment\nnutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: B12 addition sharply lowered this measured precursor pool in cultured mouse adipocytes. The cells had ECHDC1 deleted.\norganism: Mus musculus\ntissue_or_cell_type: Adipocytes\nexperimental_model: Differentiating ECHDC1-knockout mouse L929 adipocytes (Figure 4g-u)\nlimitations: Whole-cell LC-MS pools; no compartment or epimer resolution and no direct pathway flux measurement.\nexposure: ECHDC1 knockout; 2.5 micromolar supplementary B12 during differentiation\ncross_nutrient: false\nevidence_location: Full text Results: vitamin B12 supplementation; Figure 4g-u\n[dewulf-2019-l929-b12] The synthesis of branched-chain fatty acids is limited by enzymatic decarboxylation of ethyl- and methylmalonyl-CoA. (2019). https://pubmed.ncbi.nlm.nih.gov/31416829/ DOI: 10.1042/bcj20190500","model_system":"Differentiating ECHDC1-knockout mouse L929 adipocytes (Figure 4g-u)","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [dewulf-2019-l929-b12] The synthesis of branched-chain fatty acids is limited by enzymatic decarboxylation of ethyl- and methylmalonyl-CoA. (2019). https://pubmed.ncbi.nlm.nih.gov/31416829/ DOI: 10.1042/bcj20190500","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"73145023-2982-5848-aff2-8d8875d6b9c5","stable_key":"import-7fc92b9e-9cbf-556e-8719-6b5244625250","title":"Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"ad5b3a51d36e856aa7fdfd1cc23f690b094689bad87d28e1a621a54675a01c92","revision_id":"118bd616-0c13-549f-bfeb-bc439715b89c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}