Regulation of Genes Controlling Carbohydrate Metabolism in the Heart of a Hibernating Mammal
Abstract
During hibernation, mammals rely heavily on lipid stores to provide the fuel necessary to survive the winter. Pyruvate dehydrogenase kinase isozyme 4 (PDK4) plays a key role in gating carbohydrate catabolism and allowing the switch to lipid metabolism. Earlier we reported that PDK-4 was up- regulated in the heart of the thirteen-lined ground squirrel during hibernation. PDK-4 is encoded by the nuclear genome and acts by phosphorylating pyruvate dehydrogenase (PDH) thus attenuating its activity. PDH catalyzes the oxidation of pyruvate to acetyl CoA, the first irreversible step in glycolysis. Northern blot analysis shows that PDK4 message is upregulated 20-fold in heart and 5- fold in skeletal muscle during hibernation. Unlike PDKA, two other differentially expressed genes located in the mitochondrial genome are down-regulated during hibernation in heart and one is down-regulated in skeletal muscle. These genes encode NADH dehydrogenase 5 (NDH5) and NADH dehydrogenase 6 (NDH6), two subunits of NADH ubiquinone-oxidoreductase (complex I).
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 15, 2000
- Accession Number
- ADA387047
Entities
People
- Matthew T Andrews
Organizations
- North Carolina State University