{"id":"94900538-2f2b-5a2b-b7f4-955265d89097","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:ca-ncx1-regulatory-calcium","predicate":"activates","statement":"Calcium binding to the cytosolic CBD2 regulatory domain disrupts an inactive NCX1 assembly and permits exchange.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"ddb651e7-886e-58d0-9ff3-646a4e3c20aa","mechanism_event_label":"Calcium also regulates NCX1 at a site separate from the transported-ion pathway.","subject":{"id":"e359bc15-e675-5d83-b0fe-1d70814e130b","slug":"calcium-ion","display_name":"Calcium ion","entity_type_key":"ion"},"object":{"id":"e3a8401d-1368-5851-879d-c5fa748650da","slug":"slc8a1","display_name":"Na+/Ca2+ exchanger 1 / SLC8A1","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"ddb651e7-886e-58d0-9ff3-646a4e3c20aa","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:ca-ncx1-regulatory-calcium-event","event_type":"regulation","label":"Calcium also regulates NCX1 at a site separate from the transported-ion pathway.","description":"Calcium binding to the cytosolic CBD2 regulatory domain disrupts an inactive NCX1 assembly and permits exchange.","status":"provisional","compartment":{"slug":"cytosol","display_name":"Cytosol"},"participants":[{"entity":{"id":"e359bc15-e675-5d83-b0fe-1d70814e130b","slug":"calcium-ion","display_name":"Calcium ion","entity_type_key":"ion"},"role":"allosteric_ligand","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"e3a8401d-1368-5851-879d-c5fa748650da","slug":"slc8a1","display_name":"Na+/Ca2+ exchanger 1 / SLC8A1","entity_type_key":"protein"},"role":"regulated_exchanger","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"bc9ed3a1-38d5-5bc3-b2a5-9f9f7633660b","slug":"cytosol","display_name":"Cytosol","entity_type_key":"organelle"},"role":"experimental_location","stoichiometry":null,"state_label":"","sequence_order":2,"notes":"Study location; presence here is not a separate transport or causal claim."},{"entity":{"id":"f0b6bcb6-5d41-5d9d-af9f-6af1a94d5c5a","slug":"plasma-membrane","display_name":"Plasma membrane","entity_type_key":"organelle"},"role":"experimental_location","stoichiometry":null,"state_label":"","sequence_order":3,"notes":"Study location; presence here is not a separate transport or causal claim."}]},"contexts":[{"dimension":"compartment_description","value_text":"Cytosolic regulatory domain of plasma-membrane exchanger","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human cardiac NCX1; cryo-EM and functional exchange assays","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Regulatory calcium binding is distinct from calcium being transported; the measured splice form and assay conditions matter.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Calcium research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"calcium","display_name":"Calcium","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Calcium also regulates NCX1 at a site separate from the transported-ion pathway.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[ca-xue2023] Structural mechanisms of the human cardiac sodium-calcium exchanger NCX1 (2023). https://pubmed.ncbi.nlm.nih.gov/37794011/ DOI: 10.1038/s41467-023-41885-4","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"research_relationship_category","value_text":"regulation","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cardiac NCX1 expression system","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"7008b28f-21bf-57e0-aeab-29bed655476d","evidence_kind":"source_excerpt","locator":"Lines 639-650","start_line":639,"end_line":650,"excerpt":"### ca-ncx1-regulatory-calcium\nCalcium binding to the cytosolic CBD2 regulatory domain disrupts an inactive NCX1 assembly and permits exchange.\nCondition category: normal\nnutrient_topic: Calcium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Calcium also regulates NCX1 at a site separate from the transported-ion pathway.\norganism: Homo sapiens\ntissue_or_cell_type: Cardiac NCX1 expression system\nexperimental_model: Human cardiac NCX1; cryo-EM and functional exchange assays\nlimitations: Regulatory calcium binding is distinct from calcium being transported; the measured splice form and assay conditions matter.\nresearch_relationship_category: regulation\ncompartment_description: Cytosolic regulatory domain of plasma-membrane exchanger\n[ca-xue2023] Structural mechanisms of the human cardiac sodium-calcium exchanger NCX1 (2023). https://pubmed.ncbi.nlm.nih.gov/37794011/ DOI: 10.1038/s41467-023-41885-4","model_system":"Human cardiac NCX1; cryo-EM and functional exchange assays","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [ca-xue2023] Structural mechanisms of the human cardiac sodium-calcium exchanger NCX1 (2023). https://pubmed.ncbi.nlm.nih.gov/37794011/ DOI: 10.1038/s41467-023-41885-4","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"3c083fa0-59c6-50e9-af42-678d0e3c1006","stable_key":"import-434e1e27-eb90-583a-956b-62472726ffba","title":"Calcium: mechanism-first literature curation (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":"965c934d6b147f2b62f8d45ce6d7a87681a600bfe5c46a585b4704889afd3fc1","revision_id":"543ec48b-4f70-5197-9d76-f5a3c443664c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}