{"id":"8a604d71-e7db-55bb-89db-7cb778fecbc2","stable_key":"6d38d43e-01e4-5641-93be-65654271e242:zinc-trans-znt1-calcium-gradient","predicate":"enhances","statement":"In reconstituted human ZnT1 proteoliposomes, a transmembrane calcium gradient accelerated zinc transport and zinc addition drove calcium countertransport. Zinc transport persisted at a lower rate without the calcium gradient.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"3dd6a65c-df29-5054-9e44-c19cd82485b6","mechanism_event_label":"A calcium gradient helped purified human ZnT1 move zinc; some movement remained without it.","subject":{"id":"e359bc15-e675-5d83-b0fe-1d70814e130b","slug":"calcium-ion","display_name":"Calcium ion","entity_type_key":"ion"},"object":{"id":"2366f6d7-a67a-5f4a-84ba-fca072e518b8","slug":"cellular-zinc-efflux","display_name":"Cellular zinc efflux","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"3dd6a65c-df29-5054-9e44-c19cd82485b6","stable_key":"6d38d43e-01e4-5641-93be-65654271e242:zinc-trans-znt1-calcium-gradient-event","event_type":"biochemical_relationship","label":"A calcium gradient helped purified human ZnT1 move zinc; some movement remained without it.","description":"In reconstituted human ZnT1 proteoliposomes, a transmembrane calcium gradient accelerated zinc transport and zinc addition drove calcium countertransport. Zinc transport persisted at a lower rate without the calcium gradient.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"351a7f2b-7ed1-58c1-8c17-e6d520999c05","slug":"slc30a1","display_name":"Human ZnT1 (SLC30A1)","entity_type_key":"protein"},"role":"transporter","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"49c806c2-7041-5020-8b3b-fa04ffa122ac","slug":"zinc-ion","display_name":"Zinc(II) ion","entity_type_key":"ion"},"role":"countertransported_substrate","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"e359bc15-e675-5d83-b0fe-1d70814e130b","slug":"calcium-ion","display_name":"Calcium ion","entity_type_key":"ion"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"2366f6d7-a67a-5f4a-84ba-fca072e518b8","slug":"cellular-zinc-efflux","display_name":"Cellular zinc efflux","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"true","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Purified full-length human ZnT1 in proteoliposomes; supporting HEK293T transport assays","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Proteoliposomes with or without internal calcium, external zinc titration; zinc transport Km 0.38 ± 0.14 micromolar in this assay.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"In vitro transport direction depends on liposome gradients. This does not establish dietary calcium dependence or a fixed physiological Zn/Ca ratio. Calcium versus proton coupling remains incompletely resolved.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Zinc research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"zinc","display_name":"Zinc","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Homo sapiens protein","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"A calcium gradient helped purified human ZnT1 move zinc; some movement remained without it.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[zinc-trans-38669333] Structural insights into the calcium-coupled zinc export of human ZnT1. (2024). https://pubmed.ncbi.nlm.nih.gov/38669333/ DOI: 10.1126/sciadv.adk5128","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Reconstituted membrane; cultured-cell plasma membrane","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"b62b6e07-5487-5e4c-826d-ba4a995b8d8c","evidence_kind":"source_excerpt","locator":"Lines 284-295","start_line":284,"end_line":295,"excerpt":"### zinc-trans-znt1-calcium-gradient\nIn reconstituted human ZnT1 proteoliposomes, a transmembrane calcium gradient accelerated zinc transport and zinc addition drove calcium countertransport. Zinc transport persisted at a lower rate without the calcium gradient.\nCondition category: normal\nnutrient_topic: Zinc research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: A calcium gradient helped purified human ZnT1 move zinc; some movement remained without it.\norganism: Homo sapiens protein\ntissue_or_cell_type: Reconstituted membrane; cultured-cell plasma membrane\nexperimental_model: Purified full-length human ZnT1 in proteoliposomes; supporting HEK293T transport assays\nlimitations: In vitro transport direction depends on liposome gradients. This does not establish dietary calcium dependence or a fixed physiological Zn/Ca ratio. Calcium versus proton coupling remains incompletely resolved.\nexposure: Proteoliposomes with or without internal calcium, external zinc titration; zinc transport Km 0.38 ± 0.14 micromolar in this assay.\ncross_nutrient: true\n[zinc-trans-38669333] Structural insights into the calcium-coupled zinc export of human ZnT1. (2024). https://pubmed.ncbi.nlm.nih.gov/38669333/ DOI: 10.1126/sciadv.adk5128","model_system":"Purified full-length human ZnT1 in proteoliposomes; supporting HEK293T transport assays","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [zinc-trans-38669333] Structural insights into the calcium-coupled zinc export of human ZnT1. (2024). https://pubmed.ncbi.nlm.nih.gov/38669333/ DOI: 10.1126/sciadv.adk5128","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"c5ee0fee-ce5c-58de-905a-10fb0ea0723c","stable_key":"import-6d38d43e-01e4-5641-93be-65654271e242","title":"Zinc: transport, enzyme loading, 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":"2e731dd54477ec1254e97df3323e1208d38f1375effed19252e71ab4f600d13a","revision_id":"c72258b9-ac09-5408-9d44-a921ad1f96a3","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}