Phosphorylation of a 16-kDa protein by diacylglycerol-activated protein kinase C in vitro and by vasopressin in intact hepatocytes.
A 16-kDa protein present in a purified rat liver plasma membrane fraction and also in cytosol can be phosphorylated by endogenous diacylglycerol-activated protein kinase C. In intact hepatocytes prelabeled with 32P, vasopressin causes a rapid increase in the phosphorylation of a 16-kDa protein having a similar pI value to that observed in in vitro studies. These findings suggest that vasopressin-induced phosphorylation of the 16-kDa in the intact hepatocyte may reflect increased activity of protein kinase C, secondary to membrane polyphosphoinositide breakdown. Phosphorylation of the 16-kDa protein may thus be part of the coordinated mechanism associated with hormonal regulation of cellular Ca2+ fluxes.
D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D002118:Calcium / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D004075:Diglycerides / Q000502:physiology*; D005989:Glycerides / Q000502:physiology*; D008099:Liver / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D011494:Protein Kinases / Q000502:physiology*; D051381:Rats
D004075:Diglycerides; D005989:Glycerides; D008565:Membrane Proteins; D010716:Phosphatidylinositols; D010750:Phosphoproteins; D001127:Arginine Vasopressin; D011494:Protein Kinases; D002118:Calcium