Insulin rapidly increases glycerol-3-phosphate-acyltransferase activity in rat adipocytes.
Glycerol-3-phosphate acyltransferase (G3PAT) was activated by insulin in intact rat adipocytes within 1 min: this activation persisted for 10 min, and was due to a decrease in the Km of the enzyme. The addition of insulin to control adipocyte membranes also increased G3PAT activity, and this effect was mimicked by phosphatidylinositol-specific phospholipase C. Cytosol fractions from insulin-treated adipocytes stimulated G3PAT activity of control membranes, suggesting that a soluble mediator is released during insulin action, possibly through activation of a PI-specific PLC.
Vila
M C
MC
Research Service J.A. Haley Veterans' Hospital, Tampa, FL 33611.
Farese
R V
RV
D000273:Adipose Tissue / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D000818:Animals; D003600:Cytosol / Q000502:physiology; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000494:pharmacology; D051381:Rats; D013379:Substrate Specificity
D007328:Insulin; D005992:Glycerol-3-Phosphate O-Acyltransferase; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D043265:Phosphatidylinositol Diacylglycerol-Lyase