{"id":"370bf67b-45ac-51fe-bb8d-a3f8a7bfc305","stable_key":"ec174d5a-4903-5745-8646-df0e9d4265e8:qdpr-folate-repair","predicate":"opposes","statement":"Biochemical experiments identified QDPR activity that repairs oxidatively damaged tetrahydrofolate.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"35274465-7314-508a-b31b-6919c6636401","mechanism_event_label":"An enzyme also used in biopterin metabolism helps preserve reduced folate.","subject":{"id":"d255add1-af3d-5e6c-8d5e-b87c3248a7c5","slug":"qdpr","display_name":"Human quinoid dihydropteridine reductase / QDPR","entity_type_key":"protein"},"object":{"id":"b77055e9-624d-52de-9840-b1deccbc6f5e","slug":"folate-oxidative-degradation","display_name":"Oxidative degradation of reduced folates","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"35274465-7314-508a-b31b-6919c6636401","stable_key":"ec174d5a-4903-5745-8646-df0e9d4265e8:qdpr-folate-repair-event","event_type":"biochemical_relationship","label":"An enzyme also used in biopterin metabolism helps preserve reduced folate.","description":"Biochemical experiments identified QDPR activity that repairs oxidatively damaged tetrahydrofolate.","status":"provisional","compartment":{"slug":"cytosol","display_name":"Cytosol"},"participants":[{"entity":{"id":"d2b23343-c688-5fc3-9f42-bfac0050552b","slug":"tetrahydrofolate","display_name":"Tetrahydrofolate","entity_type_key":"small_molecule"},"role":"repaired folate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"d255add1-af3d-5e6c-8d5e-b87c3248a7c5","slug":"qdpr","display_name":"Human quinoid dihydropteridine reductase / QDPR","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"b77055e9-624d-52de-9840-b1deccbc6f5e","slug":"folate-oxidative-degradation","display_name":"Oxidative degradation of reduced folates","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Shared QDPR machinery connects biopterin and folate redox maintenance.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Biochemical enzyme experiments","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Assay conditions described in the linked primary study.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Repair capacity is finite; no human dietary requirement was determined.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"folate","display_name":"Folate (vitamin B9)","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"An enzyme also used in biopterin metabolism helps preserve reduced folate.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[zheng-2018] Mitochondrial One-Carbon Pathway Supports Cytosolic Folate Integrity in Cancer Cells (2018). https://pubmed.ncbi.nlm.nih.gov/30500537/ DOI: 10.1016/j.cell.2018.09.041","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cell-free and cancer-cell experiments","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"b7d4c021-07f9-5489-81e1-9de09ee1aa04","evidence_kind":"source_excerpt","locator":"Lines 1230-1241","start_line":1230,"end_line":1241,"excerpt":"### qdpr-folate-repair\nBiochemical experiments identified QDPR activity that repairs oxidatively damaged tetrahydrofolate.\nCondition category: normal\nnutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: An enzyme also used in biopterin metabolism helps preserve reduced folate.\norganism: Homo sapiens\ntissue_or_cell_type: Cell-free and cancer-cell experiments\nexperimental_model: Biochemical enzyme experiments\nlimitations: Repair capacity is finite; no human dietary requirement was determined.\nexposure: Assay conditions described in the linked primary study.\ncross_nutrient: Shared QDPR machinery connects biopterin and folate redox maintenance.\n[zheng-2018] Mitochondrial One-Carbon Pathway Supports Cytosolic Folate Integrity in Cancer Cells (2018). https://pubmed.ncbi.nlm.nih.gov/30500537/ DOI: 10.1016/j.cell.2018.09.041","model_system":"Biochemical enzyme experiments","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [zheng-2018] Mitochondrial One-Carbon Pathway Supports Cytosolic Folate Integrity in Cancer Cells (2018). https://pubmed.ncbi.nlm.nih.gov/30500537/ DOI: 10.1016/j.cell.2018.09.041","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"f4ce1a62-9582-5f7a-84f5-a23d0e1bfc68","stable_key":"import-ec174d5a-4903-5745-8646-df0e9d4265e8","title":"Folate and folic acid: mechanisms, 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":"e564d43989ece1006c95cd0748e9af6fe369074599a2eebba0a99ebff864b0dd","revision_id":"76674a33-b2a1-5e41-b71b-44399038ff7c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}