{"id":"b1643f02-3685-5cd1-b083-9d8b1f6a9e67","stable_key":"c9aa15a1-8ba2-5913-b2dd-372af304bf87:fast-pdk4","predicate":"increases_expression","statement":"Muscle PDK4 expression increased 13-fold, alongside greater inhibitory PDH phosphorylation.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"2530474d-6261-5132-950e-78093b707dc4","mechanism_event_label":"Muscle reduced access from carbohydrate into oxidation.","subject":{"id":"2d5df4b9-44d7-56a5-8ecf-7c08c0ae9f4f","slug":"fasting","display_name":"Fasting / abstention from energy intake","entity_type_key":"cellular_process"},"object":{"id":"2aac5c93-3c25-5394-b180-55d685aef78b","slug":"pdk4","display_name":"Human pyruvate dehydrogenase kinase 4 / PDK4","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"2530474d-6261-5132-950e-78093b707dc4","stable_key":"c9aa15a1-8ba2-5913-b2dd-372af304bf87:fast-pdk4-event","event_type":"observed_relationship","label":"Muscle reduced access from carbohydrate into oxidation.","description":"Muscle PDK4 expression increased 13-fold, alongside greater inhibitory PDH phosphorylation.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"2d5df4b9-44d7-56a5-8ecf-7c08c0ae9f4f","slug":"fasting","display_name":"Fasting / abstention from energy intake","entity_type_key":"cellular_process"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"2aac5c93-3c25-5394-b180-55d685aef78b","slug":"pdk4","display_name":"Human pyruvate dehydrogenase kinase 4 / PDK4","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"feb6d60e-90f7-54c6-bbc3-27df5347ac62","slug":"muscle-pdh-inhibitory-phosphorylation","display_name":"Inhibitory phosphorylation of skeletal-muscle PDH","entity_type_key":"cellular_process"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"6d908873-0745-523a-96bf-9cf25bda2676","slug":"pyruvate-dehydrogenase-complex","display_name":"Human pyruvate dehydrogenase complex","entity_type_key":"protein_complex"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Thirteen adults; seven-day fast, muscle biopsies and exercise testing.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Co-occurrence supports the pathway interpretation but does not isolate causality.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Fasting physiological-state collection; human protocols, cellular deprivation and refeeding are distinguished.","comparator":null,"unit":null,"notes":"","entity":{"slug":"fasting","display_name":"Fasting / abstention from energy intake","entity_type_key":"cellular_process"}},{"dimension":"plain_language","value_text":"Muscle reduced access from carbohydrate into oxidation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Effects of seven days' fasting on physical performance and metabolic adaptation during exercise in humans. · 2025 · https://pubmed.ncbi.nlm.nih.gov/39747857/ · DOI 10.1038/s41467-024-55418-0","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"5f552a39-555d-5da9-a6c2-9f1bef966891","evidence_kind":"source_excerpt","locator":"Lines 176-182","start_line":176,"end_line":182,"excerpt":"## fast-pdk4\nMuscle reduced access from carbohydrate into oxidation.\nMuscle PDK4 expression increased 13-fold, alongside greater inhibitory PDH phosphorylation.\nModel: Thirteen adults; seven-day fast, muscle biopsies and exercise testing.\nLimitations: Co-occurrence supports the pathway interpretation but does not isolate causality.\nEvidence access: Primary abstract\nEffects of seven days' fasting on physical performance and metabolic adaptation during exercise in humans. · 2025 · https://pubmed.ncbi.nlm.nih.gov/39747857/ · DOI 10.1038/s41467-024-55418-0","model_system":"Thirteen adults; seven-day fast, muscle biopsies and exercise testing.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access and experimental limitations specified.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"921d1eb5-2c88-52b9-9898-60b2b5bf6029","stable_key":"import-c9aa15a1-8ba2-5913-b2dd-372af304bf87","title":"Fasting: fuel switching, nutrient sensing, ketone signaling, nutrient dependencies and refeeding (2026-09-18)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"991b7fd94be84c0f1e622e0672eda03d600b388dfd7825e219aa1678d1c7983a","revision_id":"ce85d3f4-4eaf-5aee-bddb-0f0ce7fe2211","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}