{"id":"252de4a3-6f67-521e-94c3-26d4700abe1a","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:ca-calmodulin-pmca-affinity","predicate":"activates","statement":"Calmodulin increases apparent calcium affinity and ATPase activity of the erythrocyte calcium pump.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"7e9ce26f-600a-5e76-9efa-3c2837fc391c","mechanism_event_label":"Calmodulin makes the red-cell calcium pump respond more strongly to calcium.","subject":{"id":"a79ecb55-2003-5544-9599-c2136624394a","slug":"calcium-calmodulin","display_name":"Calcium/calmodulin","entity_type_key":"protein_complex"},"object":{"id":"ffcba854-d7bb-5ce0-a5fe-11be244e616e","slug":"pmca-family","display_name":"Plasma membrane calcium ATPase family","entity_type_key":"protein_family"},"evidence_count":1,"mechanism_event":{"id":"7e9ce26f-600a-5e76-9efa-3c2837fc391c","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:ca-calmodulin-pmca-affinity-event","event_type":"regulation","label":"Calmodulin makes the red-cell calcium pump respond more strongly to calcium.","description":"Calmodulin increases apparent calcium affinity and ATPase activity of the erythrocyte calcium pump.","status":"provisional","compartment":{"slug":"plasma-membrane","display_name":"Plasma membrane"},"participants":[{"entity":{"id":"a79ecb55-2003-5544-9599-c2136624394a","slug":"calcium-calmodulin","display_name":"Calcium/calmodulin","entity_type_key":"protein_complex"},"role":"activator","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"cf536e74-d4df-5b54-a78f-dd002fa5dd83","slug":"calmodulin","display_name":"Calmodulin","entity_type_key":"protein"},"role":"calcium_sensor","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"ffcba854-d7bb-5ce0-a5fe-11be244e616e","slug":"pmca-family","display_name":"Plasma membrane calcium ATPase family","entity_type_key":"protein_family"},"role":"regulated_pump","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"e359bc15-e675-5d83-b0fe-1d70814e130b","slug":"calcium-ion","display_name":"Calcium ion","entity_type_key":"ion"},"role":"transported_substrate","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"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":4,"notes":"Study location; presence here is not a separate transport or causal claim."}]},"contexts":[{"dimension":"compartment_description","value_text":"Plasma membrane","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human erythrocyte membrane ghosts with purified human or bovine calmodulin","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Membrane ghosts with controlled additions; pump isoforms were not resolved and this is not an intact-cell dose response.","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":"Calmodulin makes the red-cell calcium pump respond more strongly to calcium.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[ca-roufogalis1980] Regulation by calmodulin of the calcium affinity of the calcium-transport ATPase in human erythrocytes (1980). https://pubmed.ncbi.nlm.nih.gov/6109558/ DOI: 10.1139/o80-126","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":"Erythrocyte membranes","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"3855dbdf-d91f-5b84-b238-dc0490811e04","evidence_kind":"source_excerpt","locator":"Lines 612-623","start_line":612,"end_line":623,"excerpt":"### ca-calmodulin-pmca-affinity\nCalmodulin increases apparent calcium affinity and ATPase activity of the erythrocyte calcium pump.\nCondition category: normal\nnutrient_topic: Calcium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Calmodulin makes the red-cell calcium pump respond more strongly to calcium.\norganism: Homo sapiens\ntissue_or_cell_type: Erythrocyte membranes\nexperimental_model: Human erythrocyte membrane ghosts with purified human or bovine calmodulin\nlimitations: Membrane ghosts with controlled additions; pump isoforms were not resolved and this is not an intact-cell dose response.\nresearch_relationship_category: regulation\ncompartment_description: Plasma membrane\n[ca-roufogalis1980] Regulation by calmodulin of the calcium affinity of the calcium-transport ATPase in human erythrocytes (1980). https://pubmed.ncbi.nlm.nih.gov/6109558/ DOI: 10.1139/o80-126","model_system":"Human erythrocyte membrane ghosts with purified human or bovine calmodulin","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [ca-roufogalis1980] Regulation by calmodulin of the calcium affinity of the calcium-transport ATPase in human erythrocytes (1980). https://pubmed.ncbi.nlm.nih.gov/6109558/ DOI: 10.1139/o80-126","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}