{"id":"61ff5073-cfff-537a-bbad-667e06c2281b","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:transport-abcg2-milk-riboflavin","predicate":"reduces","statement":"Abcg2-null dams had approximately 63-fold lower free riboflavin in milk than wild type on standard chow.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"f452158b-b23b-556b-903a-3703197d6433","mechanism_event_label":"ABCG2 normally makes a major contribution to riboflavin delivery into milk.","subject":{"id":"2abc862a-67d0-5e53-a0d6-cb25ed0bfa5a","slug":"mouse-abcg2-null","display_name":"Abcg2-null mouse genotype","entity_type_key":"gene"},"object":{"id":"a07241b0-6b0d-5435-8c26-ad1fec66925c","slug":"milk-riboflavin-secretion","display_name":"Riboflavin secretion into milk","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"f452158b-b23b-556b-903a-3703197d6433","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:transport-abcg2-milk-riboflavin-event","event_type":"biochemical_relationship","label":"ABCG2 normally makes a major contribution to riboflavin delivery into milk.","description":"Abcg2-null dams had approximately 63-fold lower free riboflavin in milk than wild type on standard chow.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"ad84e56e-34b1-5591-94f6-188883af5b82","slug":"mouse-abcg2","display_name":"Mouse Abcg2 / Bcrp1","entity_type_key":"protein"},"role":"missing-efflux-transporter","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"86eb1eee-a8d1-539c-8c17-0911f69b6f1b","slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"},"role":"secreted-substrate","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"2abc862a-67d0-5e53-a0d6-cb25ed0bfa5a","slug":"mouse-abcg2-null","display_name":"Abcg2-null mouse genotype","entity_type_key":"gene"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"a07241b0-6b0d-5435-8c26-ad1fec66925c","slug":"milk-riboflavin-secretion","display_name":"Riboflavin secretion into milk","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"evidence_location","value_text":"Figure 5A","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Lactating knockout/wild-type mouse comparison with HPLC","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Chow containing 12-14 mg/kg riboflavin; lactating dams.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Mouse result; magnitude depends on chow and lactation conditions.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Riboflavin research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Mus musculus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"ABCG2 normally makes a major contribution to riboflavin delivery into milk.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[transport-abcg2-2007] Multidrug transporter ABCG2/breast cancer resistance protein secretes riboflavin (vitamin B2) into milk. (2007). https://pmc.ncbi.nlm.nih.gov/articles/PMC1800714/ DOI: 10.1128/MCB.01621-06","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Mammary milk","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":"55c0b54f-814a-50ad-a743-ad2395afbfcd","evidence_kind":"source_excerpt","locator":"Lines 544-555","start_line":544,"end_line":555,"excerpt":"### transport-abcg2-milk-riboflavin\nAbcg2-null dams had approximately 63-fold lower free riboflavin in milk than wild type on standard chow.\nCondition category: machinery_impairment\nnutrient_topic: Riboflavin research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: ABCG2 normally makes a major contribution to riboflavin delivery into milk.\norganism: Mus musculus\ntissue_or_cell_type: Mammary milk\nexperimental_model: Lactating knockout/wild-type mouse comparison with HPLC\nlimitations: Mouse result; magnitude depends on chow and lactation conditions.\nexposure: Chow containing 12-14 mg/kg riboflavin; lactating dams.\nevidence_location: Figure 5A\n[transport-abcg2-2007] Multidrug transporter ABCG2/breast cancer resistance protein secretes riboflavin (vitamin B2) into milk. (2007). https://pmc.ncbi.nlm.nih.gov/articles/PMC1800714/ DOI: 10.1128/MCB.01621-06","model_system":"Lactating knockout/wild-type mouse comparison with HPLC","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [transport-abcg2-2007] Multidrug transporter ABCG2/breast cancer resistance protein secretes riboflavin (vitamin B2) into milk. (2007). https://pmc.ncbi.nlm.nih.gov/articles/PMC1800714/ DOI: 10.1128/MCB.01621-06","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"4f7c9578-82bf-5e2d-b5c4-72a79fb4f6af","stable_key":"import-548ab9d6-3a9b-5bed-879c-17d03813b636","title":"Riboflavin: 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":"680cb6bc8249877f2410f551807f10d390fdd719014137d7414ba3420e29228d","revision_id":"7a61e299-908d-5372-860b-99ed190f9d7a","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}