Fatty acid recycling in adipocytes: a role for glyceroneogenesis and phosphoenolpyruvate carboxykinase

Biochem Soc Trans. 2003 Dec;31(Pt 6):1125-9. doi: 10.1042/bst0311125.

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 4.1.1.32]. 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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adipocytes / enzymology
  • Adipocytes / metabolism*
  • Animals
  • Fatty Acids / metabolism*
  • Glycerol / metabolism*
  • Phosphoenolpyruvate Carboxykinase (ATP) / metabolism*

Substances

  • Fatty Acids
  • Phosphoenolpyruvate Carboxykinase (ATP)
  • Glycerol