Presence of membrane‐associated phosphatidate phosphohydrolase activity in cultured islets and its stimulation by glucose

FEBS Letters

Larkins, Richard G.¹  Dunlop, Marjorie¹ 

[1] University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Parkville, 3050 Victoria, Australia

关键词: Phosphatidic acid metabolism;    Diacylglycerol;    Ca2+;    Mg2+;    (Pancreatic islet);   

DOI  :  10.1016/0014-5793(85)80158-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The cellular location at which exogenous phosphatidic acid is hydrolysed in cultured neonatal rat islets was examined. Phosphatidate phosphohydrolase activity could be demonstrated in both whole cell sonicates and isolated plasma membranes. In the whole cell fraction phosphatidic acid hydrolysis to diacylglycerol was stimulated 43% by the presence of Mg²⁺. The activity present in isolated membranes was totally dependent on the presence of Mg²⁺ and was increased in plasma membranes from glucose-stimulated islets. Following exposure of islets to low glucose concentrations, raising the Ca²⁺ concentration from 150 nM to 40 μM in the presence of Mg²⁺ did not affect the formation of diacylglycerol in whole cell fractions or plasma membranes. These results indicate the presence within the islet of membrane-bound phosphatidate phosphohydrolase activity and demonstrate its activation by glucose.

【 授权许可】

Unknown