Regulation of vasopressin-sensitive adenylate cyclase by calmodulin.
It has recently been demonstrated that an established cell line from pig kidney, LLC-PK1, is a useful model for the study of vasopressin-sensitive adenylate cyclase (Roy, C., and Ausiello, D. A. (1981) J. Biol. Chem. 256, 3415-3422; Roy, C., Hall, D., Karish, M., and Ausiello, D. A. (1981) J. Biol. Chem. 256, 3423-3427). The present study on the regulation of this enzyme has led to the demonstration of the modulation of vasopressin-stimulated adenylate cyclase by Ca2+-calmodulin. The characteristics of calmodulin regulation were similar to those described for other enzymes: (a) activation required micromolar quantities of free Ca2+; (b) maximal enzyme rates were altered but not the Km for hormone activation; (c) activity was inhibitable by trifluoperazine; and (d) activation was dependent on the Mg2+ concentration. These findings should help to define the mechanisms of action of several agents known to alter vasopressin-sensitive adenylate cyclase and cell Ca2+ content.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002122:Calcium Chloride / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000494:pharmacology*; D002147:Calmodulin / Q000494:pharmacology*; D002460:Cell Line; D007668:Kidney; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D015636:Magnesium Chloride; D013552:Swine; D014268:Trifluoperazine / Q000494:pharmacology; D014667:Vasopressins / Q000494:pharmacology*
D002135:Calcium-Binding Proteins; D002147:Calmodulin; D015636:Magnesium Chloride; D014667:Vasopressins; D014268:Trifluoperazine; D000262:Adenylyl Cyclases; D008274:Magnesium; D002122:Calcium Chloride