{"id":"40698130-412d-539b-9466-e6f3c6817625","stable_key":"4fef8d72-f107-5eb5-b2fb-483ca85465e0:k2-k2-sxr","predicate":"binds_and_activates","statement":"Vitamin K2 bound and activated human SXR and induced its CYP3A4 target gene in the tested system.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"3d5c5898-9612-520c-99ef-aeaa15e90f36","mechanism_event_label":"K2 can have a receptor-signaling role separate from protein carboxylation.","subject":{"id":"b5cf80a2-c423-5ff5-806e-fa37ddaf7303","slug":"k2","display_name":"Vitamin K2 / menaquinone family","entity_type_key":"chemical_species"},"object":{"id":"f9deea3c-fcb8-51c8-9194-438c2ad6298b","slug":"nr1i2","display_name":"Human pregnane X receptor / SXR / PXR / NR1I2","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"3d5c5898-9612-520c-99ef-aeaa15e90f36","stable_key":"4fef8d72-f107-5eb5-b2fb-483ca85465e0:k2-k2-sxr-event","event_type":"biochemical_relationship","label":"K2 can have a receptor-signaling role separate from protein carboxylation.","description":"Vitamin K2 bound and activated human SXR and induced its CYP3A4 target gene in the tested system.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"54e95ff1-4ffa-5e6f-a4cb-b47e5d2a5bda","slug":"cyp3a4","display_name":"Human cytochrome P450 3A4","entity_type_key":"protein"},"role":"transcriptional_readout","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"b5cf80a2-c423-5ff5-806e-fa37ddaf7303","slug":"k2","display_name":"Vitamin K2 / menaquinone family","entity_type_key":"chemical_species"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"f9deea3c-fcb8-51c8-9194-438c2ad6298b","slug":"nr1i2","display_name":"Human pregnane X receptor / SXR / PXR / NR1I2","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/k2-research/12920130.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"073faa7585981854cba6f1544fbe593a19b98f2ba6b9aec02c32375171e46617\", \"start_char\": 0, \"end_char\": 1589, \"text_sha256\": \"073faa7585981854cba6f1544fbe593a19b98f2ba6b9aec02c32375171e46617\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Ligand binding, gene expression and receptor-null mouse cells","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Vitamin K2 exposure and receptor deficiency","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Preclinical transcription effects; supplement-level target engagement in people is not established. Abstract calls the tested ligand K2 without distinguishing every homologue.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin K2 research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"k2","display_name":"Vitamin K2 / menaquinone family","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Human osteosarcoma cells and mouse calvarial cells","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"K2 can have a receptor-signaling role separate from protein carboxylation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[k2-p12920130] Vitamin K2 regulation of bone homeostasis is mediated by the steroid and xenobiotic receptor SXR. (2003). https://pubmed.ncbi.nlm.nih.gov/12920130/ DOI: 10.1074/jbc.m303136200","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"SXR/PXR transcription","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"d9e8f386-23db-5c6a-8051-5ef9a2422e15","evidence_kind":"source_excerpt","locator":"Lines 695-706","start_line":695,"end_line":706,"excerpt":"### k2-k2-sxr\nVitamin K2 bound and activated human SXR and induced its CYP3A4 target gene in the tested system.\nCondition category: normal\nnutrient_topic: Vitamin K2 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: K2 can have a receptor-signaling role separate from protein carboxylation.\norganism: Human osteosarcoma cells and mouse calvarial cells\ntissue_or_cell_type: SXR/PXR transcription\nexperimental_model: Ligand binding, gene expression and receptor-null mouse cells\nlimitations: Preclinical transcription effects; supplement-level target engagement in people is not established. Abstract calls the tested ligand K2 without distinguishing every homologue.\nexposure: Vitamin K2 exposure and receptor deficiency\nevidence_span: {\"source_cache\": \"artifacts/k2-research/12920130.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"073faa7585981854cba6f1544fbe593a19b98f2ba6b9aec02c32375171e46617\", \"start_char\": 0, \"end_char\": 1589, \"text_sha256\": \"073faa7585981854cba6f1544fbe593a19b98f2ba6b9aec02c32375171e46617\"}\n[k2-p12920130] Vitamin K2 regulation of bone homeostasis is mediated by the steroid and xenobiotic receptor SXR. (2003). https://pubmed.ncbi.nlm.nih.gov/12920130/ DOI: 10.1074/jbc.m303136200","model_system":"Ligand binding, gene expression and receptor-null mouse cells","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [k2-p12920130] Vitamin K2 regulation of bone homeostasis is mediated by the steroid and xenobiotic receptor SXR. (2003). https://pubmed.ncbi.nlm.nih.gov/12920130/ DOI: 10.1074/jbc.m303136200","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"dfeae572-af3d-5042-a10e-e67596f9ab28","stable_key":"import-4fef8d72-f107-5eb5-b2fb-483ca85465e0","title":"Vitamin K2: menaquinone forms, carboxylation, recycling 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":"dc31aff21110d09b025c177e03b4c5ca8349d52bf5f962285fdbfcf660c0e4f6","revision_id":"850887db-34f6-55aa-9d3e-b8fd3a4a5de3","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}