REGULATION OF TYPE-V ADENYLYL-CYCLASE BY PMA-SENSITIVE AND PMA-INSENSITIVE PROTEIN-KINASE-C ISOENZYMES IN INTACT-CELLS

Type V adenylyl cyclase (AC) was stably overexpressed in HEK293 cells (293AC-V). Forskolin-stimulated cAMP accumulation in 293AC-V was 5 tim es as great as that in control cells. PMA, a protein kinase C (PKC) ac tivator, enhanced cAMP accumulation in 293AC-V cells dose-and time-dep endently and this enhancement was abolished by staurosporine. Insulin also enhanced cAMP accumulation in 293AC-V cells. Co-transfection of P KC-zeta, but not PKC-alpha, potentiated the effects of insulin. These data suggest that type V AC activity is regulated in cells by PKC isoe nzymes through different extracellular stimuli.