{"id":"2a910ddf-beea-5b5c-b71e-6d41724e0d3d","stable_key":"db0fc92e-b5ef-5667-a4c5-3ef257edbc9b:glutathione-ggt-replenishment","predicate":"supports","statement":"GGT-positive cells replenished intracellular GSH from extracellular GSH under cysteine deprivation; GGT-negative cells did not.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"7a01ea77-0c02-5675-8e2d-c46281d98edc","mechanism_event_label":"Extracellular breakdown can support intracellular rebuilding.","subject":{"id":"f45b3142-8b5d-5e45-92f4-049010fa5658","slug":"ggt1","display_name":"Human gamma-glutamyltransferase 1 / GGT1","entity_type_key":"protein"},"object":{"id":"c6ed781b-12f5-586e-8a8b-b721c9fd82cb","slug":"ggt-positive-gsh-replenishment","display_name":"Intracellular GSH replenishment in human-GGT-expressing NIH/3T3 cells","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"7a01ea77-0c02-5675-8e2d-c46281d98edc","stable_key":"db0fc92e-b5ef-5667-a4c5-3ef257edbc9b:glutathione-ggt-replenishment-event","event_type":"biochemical_relationship","label":"Extracellular breakdown can support intracellular rebuilding.","description":"GGT-positive cells replenished intracellular GSH from extracellular GSH under cysteine deprivation; GGT-negative cells did not.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"f45b3142-8b5d-5e45-92f4-049010fa5658","slug":"ggt1","display_name":"Human gamma-glutamyltransferase 1 / GGT1","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"c6ed781b-12f5-586e-8a8b-b721c9fd82cb","slug":"ggt-positive-gsh-replenishment","display_name":"Intracellular GSH replenishment in human-GGT-expressing NIH/3T3 cells","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/glutathione-research/8099811.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"53a6b1a1855863d8fe1d0be289055e7cd6ca39b33e936e82dfed2d7d084c9d5b\", \"start_char\": 0, \"end_char\": 984, \"text_sha256\": \"53a6b1a1855863d8fe1d0be289055e7cd6ca39b33e936e82dfed2d7d084c9d5b\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human GGT transfection in mouse fibroblasts","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Cysteine-free medium supplemented with extracellular GSH","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Precursor salvage after extracellular cleavage; not proof of intact oral GSH entry into every tissue.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Glutathione research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"glutathione","display_name":"GSH","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Human GGT; NIH/3T3 host","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Extracellular breakdown can support intracellular rebuilding.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[glutathione-p8099811] Extracellular glutathione is a source of cysteine for cells that express gamma-glutamyl transpeptidase. (1993). https://pubmed.ncbi.nlm.nih.gov/8099811/ DOI: 10.1021/bi00075a026","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cell surface and intracellular pools","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"e6f8338e-b859-5bc4-bf57-5a8194f7cdc8","evidence_kind":"source_excerpt","locator":"Lines 645-656","start_line":645,"end_line":656,"excerpt":"### glutathione-ggt-replenishment\nGGT-positive cells replenished intracellular GSH from extracellular GSH under cysteine deprivation; GGT-negative cells did not.\nCondition category: normal\nnutrient_topic: Glutathione research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Extracellular breakdown can support intracellular rebuilding.\norganism: Human GGT; NIH/3T3 host\ntissue_or_cell_type: Cell surface and intracellular pools\nexperimental_model: Human GGT transfection in mouse fibroblasts\nlimitations: Precursor salvage after extracellular cleavage; not proof of intact oral GSH entry into every tissue.\nexposure: Cysteine-free medium supplemented with extracellular GSH\nevidence_span: {\"source_cache\": \"artifacts/glutathione-research/8099811.abstract.txt\", \"locator\": \"Primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"53a6b1a1855863d8fe1d0be289055e7cd6ca39b33e936e82dfed2d7d084c9d5b\", \"start_char\": 0, \"end_char\": 984, \"text_sha256\": \"53a6b1a1855863d8fe1d0be289055e7cd6ca39b33e936e82dfed2d7d084c9d5b\"}\n[glutathione-p8099811] Extracellular glutathione is a source of cysteine for cells that express gamma-glutamyl transpeptidase. 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