{"id":"80ceff91-9757-56a2-bfc1-2eb31ec3cf49","stable_key":"db0fc92e-b5ef-5667-a4c5-3ef257edbc9b:glutathione-ggt-cysteine","predicate":"makes_available_from_gsh","statement":"Human-GGT-expressing fibroblasts used extracellular GSH as a cysteine source in cysteine-free medium.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"4c094234-521b-521a-a4b8-8e457cc23a59","mechanism_event_label":"Breaking down glutathione outside a cell can supply building blocks inside.","subject":{"id":"f45b3142-8b5d-5e45-92f4-049010fa5658","slug":"ggt1","display_name":"Human gamma-glutamyltransferase 1 / GGT1","entity_type_key":"protein"},"object":{"id":"ff209c82-1f28-5bce-bfea-84f5e25251ab","slug":"extracellular-cysteine","display_name":"extracellular cysteine","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"4c094234-521b-521a-a4b8-8e457cc23a59","stable_key":"db0fc92e-b5ef-5667-a4c5-3ef257edbc9b:glutathione-ggt-cysteine-event","event_type":"biochemical_relationship","label":"Breaking down glutathione outside a cell can supply building blocks inside.","description":"Human-GGT-expressing fibroblasts used extracellular GSH as a cysteine source in cysteine-free medium.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"b44c9e27-4bbb-52d3-a022-14cddded5073","slug":"glutathione","display_name":"GSH","entity_type_key":"small_molecule"},"role":"extracellular_source","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"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":1,"notes":""},{"entity":{"id":"ff209c82-1f28-5bce-bfea-84f5e25251ab","slug":"extracellular-cysteine","display_name":"extracellular cysteine","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"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":"Breaking down glutathione outside a cell can supply building blocks inside.","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":"df04c7fe-dac8-5200-8772-c358cd945717","evidence_kind":"source_excerpt","locator":"Lines 632-643","start_line":632,"end_line":643,"excerpt":"### glutathione-ggt-cysteine\nHuman-GGT-expressing fibroblasts used extracellular GSH as a cysteine source in cysteine-free medium.\nCondition category: normal\nnutrient_topic: Glutathione research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Breaking down glutathione outside a cell can supply building blocks inside.\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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