{"id":"503553b6-42c8-59ef-9e3b-7ca620c44168","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:hff1-mmut-ko-lowers-propionate-label","predicate":"knockout-reduces","statement":"MMUT knockout reduced propionate-derived protein labeling about sixfold in HFF1 human fibroblasts.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"e987ad0b-7729-512d-9c57-c46d30071645","mechanism_event_label":"These human fibroblasts relied strongly on MMUT for the measured use of propionate carbon.","subject":{"id":"7c1e45c3-bb73-5e63-8b3d-4bb3c96ed819","slug":"mmut-human-gene","display_name":"MMUT gene (Homo sapiens)","entity_type_key":"gene"},"object":{"id":"83e7171b-2769-5d0a-b65c-95f5c6bd3b3d","slug":"propionate-carbon-protein-incorporation","display_name":"Propionate-derived carbon incorporation into cellular protein","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"e987ad0b-7729-512d-9c57-c46d30071645","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:hff1-mmut-ko-lowers-propionate-label-event","event_type":"biochemical_relationship","label":"These human fibroblasts relied strongly on MMUT for the measured use of propionate carbon.","description":"MMUT knockout reduced propionate-derived protein labeling about sixfold in HFF1 human fibroblasts.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"7c1e45c3-bb73-5e63-8b3d-4bb3c96ed819","slug":"mmut-human-gene","display_name":"MMUT gene (Homo sapiens)","entity_type_key":"gene"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"83e7171b-2769-5d0a-b65c-95f5c6bd3b3d","slug":"propionate-carbon-protein-incorporation","display_name":"Propionate-derived carbon incorporation into cellular protein","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; Figure 2C,E","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"HFF1 human fibroblasts with two CRISPR guides","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"MMUT CRISPR knockout versus OR7G3 guide control; [14C]propionate","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Protein labeling integrates metabolism and protein synthesis; not direct MMUT flux.","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":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"These human fibroblasts relied strongly on MMUT for the measured use of propionate carbon.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[2024-propionate-cell-dependence] Differential utilization of vitamin B12-dependent and independent pathways for propionate metabolism across human cells. (2024). https://pubmed.ncbi.nlm.nih.gov/39128713/ DOI: 10.1016/j.jbc.2024.107662","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Foreskin fibroblasts","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":"2f37d0b3-e36b-5e79-ae1c-ac0d921b1ccf","evidence_kind":"source_excerpt","locator":"Lines 1300-1312","start_line":1300,"end_line":1312,"excerpt":"### hff1-mmut-ko-lowers-propionate-label\nMMUT knockout reduced propionate-derived protein labeling about sixfold in HFF1 human fibroblasts.\nCondition category: machinery_impairment\nnutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: These human fibroblasts relied strongly on MMUT for the measured use of propionate carbon.\norganism: Homo sapiens\ntissue_or_cell_type: Foreskin fibroblasts\nexperimental_model: HFF1 human fibroblasts with two CRISPR guides\nlimitations: Protein labeling integrates metabolism and protein synthesis; not direct MMUT flux.\nexposure: MMUT CRISPR knockout versus OR7G3 guide control; [14C]propionate\ncross_nutrient: false\nevidence_location: Full text Results; Figure 2C,E\n[2024-propionate-cell-dependence] Differential utilization of vitamin B12-dependent and independent pathways for propionate metabolism across human cells. (2024). https://pubmed.ncbi.nlm.nih.gov/39128713/ DOI: 10.1016/j.jbc.2024.107662","model_system":"HFF1 human fibroblasts with two CRISPR guides","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [2024-propionate-cell-dependence] Differential utilization of vitamin B12-dependent and independent pathways for propionate metabolism across human cells. (2024). https://pubmed.ncbi.nlm.nih.gov/39128713/ DOI: 10.1016/j.jbc.2024.107662","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}