Inhibitory effects of calmodulin antagonists on plasma membrane cyclases in Tetrahymena: calmodulin-dependent guanylate cyclase and calmodulin-independent adenylate cyclase.

Abstract

Trifluoperazine was shown previously to inhibit the activation of Tetrahymena guanylate cyclase activity by calmodulin [S. Nagao, S. Kudo and Y Nozawa, Biochem. Pharmac. 19, 2709 (1981)]. The present paper reports that N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), another representative calmodulin inhibitor, inhibited the calmodulin-induced activation of the guanylate cyclase, and that trifluoperazine and W-7 also inhibited Tetrahymena adenylate cyclase. The adenylate cyclase activity was found to be present in a membrane-bound form and not to be influenced by calmodulin. The inhibitions of the adenylate cyclase activity by these agents were dose-dependent and not Ca2+-dependent. These findings suggest that the inhibitory actions of these drugs may not necessarily be specific for calmodulin-dependent enzymes in T. pyriformis.

Cite this paper

@article{Nagao1983InhibitoryEO, title={Inhibitory effects of calmodulin antagonists on plasma membrane cyclases in Tetrahymena: calmodulin-dependent guanylate cyclase and calmodulin-independent adenylate cyclase.}, author={Shizuko Nagao and Sanae Kudo and Yoshinori Nozawa}, journal={Biochemical pharmacology}, year={1983}, volume={32 17}, pages={2501-4} }