{"id":"d316f1f5-3978-5bcf-aaa9-a408de5ea1e7","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:b12-abs-amn-endocytosis","predicate":"enables","statement":"Human AMN coexpressed with rat cubilin 1-1389 enabled IF-B12 internalization in CHO-K1 cells; either intact FXNPXF cytoplasmic motif supported uptake.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"ec4cf217-1901-53b5-93b6-bb0def4f5d36","mechanism_event_label":"Amnionless supplies signals that bring receptor-bound B12 into cells.","subject":{"id":"bbd594ac-365b-507f-954d-20a0df38312d","slug":"amn","display_name":"Human amnionless / AMN","entity_type_key":"protein"},"object":{"id":"ffacb0b0-ba03-59b7-aa3a-b2839cfb7d5b","slug":"cubam-if-cobalamin-endocytosis","display_name":"Cubam-mediated IF-cobalamin endocytosis","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"ec4cf217-1901-53b5-93b6-bb0def4f5d36","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:b12-abs-amn-endocytosis-event","event_type":"biochemical_relationship","label":"Amnionless supplies signals that bring receptor-bound B12 into cells.","description":"Human AMN coexpressed with rat cubilin 1-1389 enabled IF-B12 internalization in CHO-K1 cells; either intact FXNPXF cytoplasmic motif supported uptake.","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":"nutrient","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"b6fc3dff-b990-5b47-be50-a469eee88d9e","slug":"rat-mini-cubilin-cub1-8","display_name":"Rat cubilin 1-1389 minireceptor","entity_type_key":"protein_state"},"role":"binding-subunit","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"bbd594ac-365b-507f-954d-20a0df38312d","slug":"amn","display_name":"Human amnionless / AMN","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"ffacb0b0-ba03-59b7-aa3a-b2839cfb7d5b","slug":"cubam-if-cobalamin-endocytosis","display_name":"Cubam-mediated IF-cobalamin endocytosis","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"false","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human AMN plus rat cubilin minireceptor in CHO-K1 cells","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Labeled human/porcine IF-B12 at 37 degrees C over 1-8 hours","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Reconstituted mixed-species system. Cell-associated radiolabel includes surface-bound cargo and must not be equated with internalized ligand.","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":"Human AMN; rat cubilin; Chinese hamster host cells; human/porcine IF reagents","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Amnionless supplies signals that bring receptor-bound B12 into cells.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[pedersen-2010-amn-endocytosis] AMN directs endocytosis of the intrinsic factor-vitamin B(12) receptor cubam by engaging ARH or Dab2. (2010). https://pubmed.ncbi.nlm.nih.gov/20088845/ DOI: 10.1111/j.1600-0854.2010.01042.x","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Engineered plasma-membrane endocytosis model","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"c0f3366f-c189-537d-9e86-28b1fe3b91d1","evidence_kind":"source_excerpt","locator":"Lines 478-489","start_line":478,"end_line":489,"excerpt":"### b12-abs-amn-endocytosis\nHuman AMN coexpressed with rat cubilin 1-1389 enabled IF-B12 internalization in CHO-K1 cells; either intact FXNPXF cytoplasmic motif supported uptake.\nCondition category: normal\nnutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Amnionless supplies signals that bring receptor-bound B12 into cells.\norganism: Human AMN; rat cubilin; Chinese hamster host cells; human/porcine IF reagents\ntissue_or_cell_type: Engineered plasma-membrane endocytosis model\nexperimental_model: Human AMN plus rat cubilin minireceptor in CHO-K1 cells\nlimitations: Reconstituted mixed-species system. Cell-associated radiolabel includes surface-bound cargo and must not be equated with internalized ligand.\nexposure: Labeled human/porcine IF-B12 at 37 degrees C over 1-8 hours\ncross_nutrient: false\n[pedersen-2010-amn-endocytosis] AMN directs endocytosis of the intrinsic factor-vitamin B(12) receptor cubam by engaging ARH or Dab2. (2010). https://pubmed.ncbi.nlm.nih.gov/20088845/ DOI: 10.1111/j.1600-0854.2010.01042.x","model_system":"Human AMN plus rat cubilin minireceptor in CHO-K1 cells","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [pedersen-2010-amn-endocytosis] AMN directs endocytosis of the intrinsic factor-vitamin B(12) receptor cubam by engaging ARH or Dab2. (2010). https://pubmed.ncbi.nlm.nih.gov/20088845/ DOI: 10.1111/j.1600-0854.2010.01042.x","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}