{"id":"0b3ece36-5261-5cb6-884f-c14079bd1cc0","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:b12-lmbrd1-escort-huh7","predicate":"promotes-lysosomal-localization-of","statement":"In HuH7 cells expressing human ABCD4-HA, adding LMBD1-GFP shifted ABCD4 from an ER-like distribution toward LAMP1-positive lysosomes.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"6c51721b-d2de-50ce-8e1c-5c9d05281e09","mechanism_event_label":"LMBD1 helped the B12 transporter reach lysosomes.","subject":{"id":"3cf57c43-b33e-5c4e-a53d-dc80695775bb","slug":"lmbrd1","display_name":"Human LMBD1 lysosomal membrane protein","entity_type_key":"protein"},"object":{"id":"831afa98-dacd-516d-ae1e-680432a78525","slug":"abcd4","display_name":"Human ABCD4 lysosomal cobalamin transporter","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"6c51721b-d2de-50ce-8e1c-5c9d05281e09","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:b12-lmbrd1-escort-huh7-event","event_type":"biochemical_relationship","label":"LMBD1 helped the B12 transporter reach lysosomes.","description":"In HuH7 cells expressing human ABCD4-HA, adding LMBD1-GFP shifted ABCD4 from an ER-like distribution toward LAMP1-positive lysosomes.","status":"provisional","compartment":{"slug":"lysosome","display_name":"Lysosome"},"participants":[{"entity":{"id":"b6d9b937-895d-5e0a-8cc5-0454a0b7d373","slug":"vitamin-b12","display_name":"Vitamin B12 (cobalamins)","entity_type_key":"chemical_species"},"role":"transport cargo","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"ea69f7d2-43d8-5b62-8ed6-60d6ad580813","slug":"endoplasmic-reticulum","display_name":"Endoplasmic reticulum","entity_type_key":"organelle"},"role":"starting compartment","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"be46855c-b0c2-51f1-9bd8-80f9d0f009cf","slug":"lysosome","display_name":"Lysosome","entity_type_key":"organelle"},"role":"destination","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"3cf57c43-b33e-5c4e-a53d-dc80695775bb","slug":"lmbrd1","display_name":"Human LMBD1 lysosomal membrane protein","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"831afa98-dacd-516d-ae1e-680432a78525","slug":"abcd4","display_name":"Human ABCD4 lysosomal cobalamin transporter","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"false","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_location","value_text":"Results: Figures 1, 6, 7; Methods: cell lines and CRISPR","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human HuH7 tagged-protein localization","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"ABCD4-HA stable expression and transient LMBD1-GFP","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Tagged overexpression; colocalization does not measure cobalamin 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":"LMBD1 helped the B12 transporter reach lysosomes.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[kawaguchi-2016-lmbd1-escort] Translocation of the ABC transporter ABCD4 from the endoplasmic reticulum to lysosomes requires the escort protein LMBD1 (2016). https://pubmed.ncbi.nlm.nih.gov/27456980/ DOI: 10.1038/srep30183","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Hepatoma cell line","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"a1b48dc4-db0e-5335-9df6-73f47be87aea","evidence_kind":"source_excerpt","locator":"Lines 571-583","start_line":571,"end_line":583,"excerpt":"### b12-lmbrd1-escort-huh7\nIn HuH7 cells expressing human ABCD4-HA, adding LMBD1-GFP shifted ABCD4 from an ER-like distribution toward LAMP1-positive lysosomes.\nCondition category: normal\nnutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: LMBD1 helped the B12 transporter reach lysosomes.\norganism: Homo sapiens\ntissue_or_cell_type: Hepatoma cell line\nexperimental_model: Human HuH7 tagged-protein localization\nlimitations: Tagged overexpression; colocalization does not measure cobalamin flux.\nexposure: ABCD4-HA stable expression and transient LMBD1-GFP\ncross_nutrient: false\nevidence_location: Results: Figures 1, 6, 7; Methods: cell lines and CRISPR\n[kawaguchi-2016-lmbd1-escort] Translocation of the ABC transporter ABCD4 from the endoplasmic reticulum to lysosomes requires the escort protein LMBD1 (2016). https://pubmed.ncbi.nlm.nih.gov/27456980/ DOI: 10.1038/srep30183","model_system":"Human HuH7 tagged-protein localization","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [kawaguchi-2016-lmbd1-escort] Translocation of the ABC transporter ABCD4 from the endoplasmic reticulum to lysosomes requires the escort protein LMBD1 (2016). https://pubmed.ncbi.nlm.nih.gov/27456980/ DOI: 10.1038/srep30183","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}