[show abstract][hide abstract] ABSTRACT: FA (fatty acid) recycling in adipose tissue appears to be an important pathway for regulating FA release into the blood during fasting. Re-esterification requires G3P (glycerol 3-phosphate), which cannot be synthesized from glucose because glycolysis is much reduced under such circumstances. In addition, G3P can scarcely originate from glycerol since glycerol kinase has a very low activity in white adipose tissue. It was shown about 35 years ago that a metabolic pathway named glyceroneogenesis, which allows G3P synthesis from non-carbohydrate precursors like pyruvate, lactate or amino acids, is activated during fasting. The major enzyme in this pathway was shown to be PEPCK-C [cytosolic phosphoenolpyruvate carboxykinase (GTP); EC 126.96.36.199]. The present review analyses the mechanisms by which a series of hormones and nutrients affect PEPCK-C gene transcription and glyceroneogenesis and describes evidence for dysregulation of this pathway in type 2 diabetes.
Biochemical Society Transactions 01/2004; 31(Pt 6):1125-9. · 2.59 Impact Factor