{"id":"f8ac6dce-daf2-5438-acd4-503c1c735fda","stable_key":"dff9f743-3766-5f20-a71e-d6d2bd5bfb6f:va-sig-rxra-vdr-partnership","predicate":"heterodimerizes-with","statement":"RXRA formed a VDR complex and enhanced binding to the osteopontin vitamin D response element.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"0338bad5-c37d-596d-bb48-9110d85b66c1","mechanism_event_label":"Vitamin D signaling shares RXRA receptor machinery with retinoid pathways.","subject":{"id":"7dc1ce11-f208-5187-95d9-96b07927df6a","slug":"rxra","display_name":"Retinoid X receptor alpha","entity_type_key":"protein"},"object":{"id":"d725020b-bacc-5e90-b370-cda246025c91","slug":"vdr","display_name":"Vitamin D receptor / VDR","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"0338bad5-c37d-596d-bb48-9110d85b66c1","stable_key":"dff9f743-3766-5f20-a71e-d6d2bd5bfb6f:va-sig-rxra-vdr-partnership-event","event_type":"biochemical_relationship","label":"Vitamin D signaling shares RXRA receptor machinery with retinoid pathways.","description":"RXRA formed a VDR complex and enhanced binding to the osteopontin vitamin D response element.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"ce392c9e-6483-5914-b18b-d6a2520dbbf6","slug":"vitamin-a","display_name":"Vitamin A","entity_type_key":"chemical_species"},"role":"nutrient-context","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"caa5f891-3bee-5acc-bbff-b99c4037d58e","slug":"rxra-vdr","display_name":"RXR alpha-VDR heterodimer","entity_type_key":"protein_complex"},"role":"complex","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"f5156c24-108f-5746-b114-ed764e79a3f4","slug":"calcitriol","display_name":"Calcitriol","entity_type_key":"small_molecule"},"role":"vitamin-d-hormone-context","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"7dc1ce11-f208-5187-95d9-96b07927df6a","slug":"rxra","display_name":"Retinoid X receptor alpha","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"d725020b-bacc-5e90-b370-cda246025c91","slug":"vdr","display_name":"Vitamin D receptor / VDR","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Vitamin A-vitamin D: shared receptor partner; no supplementation or deficiency rescue tested.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_locator","value_text":"Figure 3","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant receptors, gel shifts, coimmunoprecipitation and CV-1 reporters.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Reconstituted VDR/RXRA","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Does not prove vitamin A intake enhances calcium absorption.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin A research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-a","display_name":"Vitamin A","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Recombinant receptors","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Vitamin D signaling shares RXRA receptor machinery with retinoid pathways.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[va-kliewer-1992] Retinoid X receptor interacts with nuclear receptors in retinoic acid, thyroid hormone and vitamin D3 signalling (1992). https://pubmed.ncbi.nlm.nih.gov/1310351/ DOI: 10.1038/355446a0","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cell-free DNA-binding assay","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"f75e680f-ac3f-5566-929f-c3a42c29340b","evidence_kind":"source_excerpt","locator":"Lines 1095-1107","start_line":1095,"end_line":1107,"excerpt":"### va-sig-rxra-vdr-partnership\nRXRA formed a VDR complex and enhanced binding to the osteopontin vitamin D response element.\nCondition category: normal\nnutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Vitamin D signaling shares RXRA receptor machinery with retinoid pathways.\norganism: Recombinant receptors\ntissue_or_cell_type: Cell-free DNA-binding assay\nexperimental_model: Recombinant receptors, gel shifts, coimmunoprecipitation and CV-1 reporters.\nlimitations: Does not prove vitamin A intake enhances calcium absorption.\nevidence_locator: Figure 3\ncross_nutrient: Vitamin A-vitamin D: shared receptor partner; no supplementation or deficiency rescue tested.\nexposure: Reconstituted VDR/RXRA\n[va-kliewer-1992] Retinoid X receptor interacts with nuclear receptors in retinoic acid, thyroid hormone and vitamin D3 signalling (1992). https://pubmed.ncbi.nlm.nih.gov/1310351/ DOI: 10.1038/355446a0","model_system":"Recombinant receptors, gel shifts, coimmunoprecipitation and CV-1 reporters.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [va-kliewer-1992] Retinoid X receptor interacts with nuclear receptors in retinoic acid, thyroid hormone and vitamin D3 signalling (1992). https://pubmed.ncbi.nlm.nih.gov/1310351/ DOI: 10.1038/355446a0","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"0c5474e2-be48-547b-b287-9c07a59c9ff1","stable_key":"import-dff9f743-3766-5f20-a71e-d6d2bd5bfb6f","title":"Vitamin A: forms, mechanisms, deficiency and excess (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":"b217224b262abbd77d6a0c8c9beefff9c022fae4d31e2a5273915d769b9a6546","revision_id":"61008909-871f-575c-b5e2-21542689ea3c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}