{"id":"d23553ed-ffe2-5dfe-a62f-dda9d33048f1","stable_key":"0f17db03-207f-5910-ac8e-13dfc2f378ce:pertussis-toxin-removes-low-mg-pth-block","predicate":"prevents-low-mg-inhibition-of","statement":"Pertussis-toxin pretreatment abolished the suppression of PTH release by low Mg in the parathyroid-cell assay.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"cc1b624f-c621-56a6-8efb-1b4efc874d28","mechanism_event_label":"Blocking Gi/o signaling removed the low-Mg secretory brake, placing these signaling proteins in the experimental pathway.","subject":{"id":"7824cac0-054d-5565-8be0-af68fd125901","slug":"pertussis-toxin","display_name":"Pertussis toxin","entity_type_key":"protein_complex"},"object":{"id":"003d1a6f-e672-5a4e-b78b-fac58daaa987","slug":"pth-secretion","display_name":"Parathyroid hormone secretion","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"cc1b624f-c621-56a6-8efb-1b4efc874d28","stable_key":"0f17db03-207f-5910-ac8e-13dfc2f378ce:pertussis-toxin-removes-low-mg-pth-block-event","event_type":"biochemical_relationship","label":"Blocking Gi/o signaling removed the low-Mg secretory brake, placing these signaling proteins in the experimental pathway.","description":"Pertussis-toxin pretreatment abolished the suppression of PTH release by low Mg in the parathyroid-cell assay.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"1ca418db-3137-5dba-8ae2-8941432f0156","slug":"g-alpha-i-o","display_name":"Gi/o-family G protein alpha subunits","entity_type_key":"protein_family"},"role":"inhibited pathway","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"bff427ab-35f9-59c2-bb24-fd5953bbaec2","slug":"magnesium-ion","display_name":"Mg2+","entity_type_key":"ion"},"role":"low-exposure variable","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"1c0d5c58-d358-5501-9bdf-8999bcf79fd4","slug":"casr","display_name":"Calcium-sensing receptor / CaSR","entity_type_key":"protein"},"role":"upstream receptor context","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"7824cac0-054d-5565-8be0-af68fd125901","slug":"pertussis-toxin","display_name":"Pertussis toxin","entity_type_key":"protein_complex"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"003d1a6f-e672-5a4e-b78b-fac58daaa987","slug":"pth-secretion","display_name":"Parathyroid hormone secretion","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; 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unverified.","entity":null}],"evidence":[{"id":"95696a70-e397-5949-ab27-2ca2ba969d27","evidence_kind":"source_excerpt","locator":"Lines 445-455","start_line":445,"end_line":455,"excerpt":"### pertussis-toxin-removes-low-mg-pth-block\nPertussis-toxin pretreatment abolished the suppression of PTH release by low Mg in the parathyroid-cell assay.\nCondition category: nutrient_deficiency\nnutrient_topic: Magnesium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Blocking Gi/o signaling removed the low-Mg secretory brake, placing these signaling proteins in the experimental pathway.\norganism: Homo sapiens\ntissue_or_cell_type: Parathyroid cells in vitro\nexperimental_model: Dispersed human parathyroid cells from hyperparathyroid tissue\nlimitations: Pharmacologic pathway probe, not evidence for toxin use in patients; no full in-vivo chain tested.\ncross_nutrient: magnesium -> CaSR/PTH -> calcium\n[quitterer-2001-magnesium-paradox] Paradoxical block of parathormone secretion is mediated by increased activity of G alpha subunits (2001). https://pubmed.ncbi.nlm.nih.gov/11102444/ DOI: 10.1074/jbc.M007727200","model_system":"Dispersed human parathyroid cells from hyperparathyroid tissue","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [quitterer-2001-magnesium-paradox] Paradoxical block of parathormone secretion is mediated by increased activity of G alpha subunits (2001). https://pubmed.ncbi.nlm.nih.gov/11102444/ DOI: 10.1074/jbc.M007727200","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"dd101e28-1a2e-5a48-9d1e-809c77514866","stable_key":"import-0f17db03-207f-5910-ac8e-13dfc2f378ce","title":"Magnesium: cross-nutrient mechanisms and deficiency (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":"e111c412f57143a17e8e65e74e8f7888b5bb9a61099873f4767f527fac19bb07","revision_id":"6b7f04f2-66ed-5859-955f-c2b50d4bf041","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}