Angiotensin II but not potassium induces subcellular redistribution of protein kinase C in bovine adrenal glomerulosa cells.
The distribution of calcium-activated, phospholipid-dependent protein kinase (protein kinase C) between cytosol and membrane fractions was examined in bovine adrenal glomerulosa cells treated with angiotensin II or potassium. Protein kinase C was isolated from cytosol and from detergent-solubilized particulate fractions by DEAE-cellulose chromatography. A major peak of activity for both the soluble and particulate forms of adrenal glomerulosa protein kinase C was eluted at 0.05-0.09 M NaCl. The soluble and particulate forms were found to constitute about 95 and 5%, respectively, of the total enzyme activity in unstimulated cells. A second peak of kinase activity was eluted with 0.15-0.19 M NaCl, which was not dependent on the presence of phospholipids. Exposure of isolated cells for 20 min to 10(-8) M angiotensin II resulted in a decrease in cytosolic activity to 30-40% of control values, and in a corresponding increase in protein kinase C activity associated with the particulate fraction. This hormone-induced redistribution was found to be dose-dependent with an ED50 of 2 nM for angiotensin II, and it occurred rapidly, reaching a plateau within 5-10 min. It was prevented by the specific antagonist [Sar1,Ala8]angiotensin II. By contrast, stimulation with 12 mM KCl did not change the subcellular distribution of protein kinase C activity. These results suggest that redistribution of protein kinase C represents an early step in the post-receptor activation cascade following angiotensin II, but not potassium stimulation of adrenal glomerulosa cells.
D000311:Adrenal Glands / Q000187:drug effects / Q000201:enzymology*; D000450:Aldosterone / Q000096:biosynthesis; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D002417:Cattle; D002458:Cell Fractionation; D002462:Cell Membrane / Q000201:enzymology; D003600:Cytosol / Q000201:enzymology; D007700:Kinetics; D011188:Potassium / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism*
D000804:Angiotensin II; D000450:Aldosterone; D011493:Protein Kinase C; D011188:Potassium