Casein kinase II stimulates rat liver mitochondrial glycerophosphate acyltransferase activity

Biochem Biophys Res Commun. 2002 Sep 6;296(5):1091-6. doi: 10.1016/s0006-291x(02)02064-8.

Abstract

Rat liver mitochondrial glycerophosphate acyltransferase (mtGAT) possesses 14 consensus sites for casein kinase II (CKII) phosphorylation. To study the functional relevance of phosphorylation to the activity of mtGAT, we treated isolated rat liver mitochondria with CKII and found that CKII stimulated mtGAT activity approximately 2-fold. Protein phosphatase-lambda treatment reversed the stimulation of mtGAT by CKII. Labeling of both solubilized and non-solubilized mitochondria with CKII and [gamma-32P]ATP resulted in a 32P-labeled protein of 85kDa, the molecular weight of mtGAT. Our findings suggest that CKII stimulates mtGAT activity by phosphorylation of the acyltransferase. The significance of this observation with respect to hormonal control of the enzyme is discussed.

Publication types

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

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Casein Kinase II
  • Enzyme Activation
  • Glycerol-3-Phosphate O-Acyltransferase / chemistry
  • Glycerol-3-Phosphate O-Acyltransferase / metabolism*
  • Male
  • Mitochondria, Liver / drug effects
  • Mitochondria, Liver / enzymology*
  • Mitochondrial Proteins / metabolism
  • Phosphoprotein Phosphatases / pharmacology
  • Phosphorylation
  • Protein Serine-Threonine Kinases / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Sequence Analysis, Protein

Substances

  • Mitochondrial Proteins
  • Adenosine Triphosphate
  • Glycerol-3-Phosphate O-Acyltransferase
  • Casein Kinase II
  • Protein Serine-Threonine Kinases
  • Phosphoprotein Phosphatases