ROLE OF PROTEIN-KINASE-C AND CARBOXYL-TERMINAL REGION IN ACUTE DESENSITIZATION OF VASOPRESSIN V1A RECEPTOR

The role of protein kinase C activation and carboxyl-terminal region i n rapid desensitization of the vasopressin Via receptor was investigat ed in Xenopus oocytes. Preincubation of the oocytes with vasopressin o r with the diacylglycerol analog 1-oleoyl-2-acetyl-sn-glycerol (GAG), or direct injection of active protein kinase C, all blunted the calciu m response of the Via receptor, Truncation of the 51 terminal amino ac ids (S374STOP) modified neither the intracellular calcium response to vasopressin nor its desensitization by vasopressin or GAG. These data suggest that desensitization of the Via receptor is mediated by PKC ac tivation and that its carboxyl-terminal domain is not required for sig nal transduction and rapid desensitization, (C) 1997 Federation of Eur opean Biochemical Societies.