Effects of okadaic acid on the activities of two distinct phosphatidate phosphohydrolases in rat hepatocytes

FEBS Letters

Brindley, David N.¹  Hatch, Grant M.¹  Martin, Ashley¹  Gomez-Muñoz, Antonio¹  Vance, Dennis E.¹  Jamal, Zahirali¹ 

[1] Department of Biochemistry and Lipid and Lipoprotein Research Group, Faculty of Medicine, University of Alberta, Edmonton, Alberta T6G 2S2, Canada

关键词: Diacylglycerol;    Phosphatidylcholine;    Protein phosphatase;    Signal transduction;    Triacylglycerol;   

DOI  :  10.1016/0014-5793(92)80219-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Incubation of hepatocytes with okadaic acid displaced the N-ethylmaleimide-sensitive phosphatidate phosphohydrolase from the membrane fraction into the cytosol and partially prevented the oleate-induced movement of phosphohydrolase from cytosol to membranes. However, higher concentrations of oleate still caused translocation and activation of the phosphohydrolase. This enzyme is stimulated by Mg²⁺, and is probably involved in glycerolipid synthesis. Okadaic acid also decreased the concentration of diacylglycerol within the hepatocytes. Okadaic acid had no observable effect on the activity of an N-ethylmaleimide-insensitive phosphatidate phosphohydrolase which remained firmly attached to membranes. This activity is not stimulated by Mg²⁺ and is probably involved in signal transduction by the phospholipase D pathway.

【 授权许可】

Unknown