Open AccessMechanism of Isoprenaline-Stimulated Diacylglycerol Formation in Rat Parotid Acinar Cells
Author(s) -
Keiichi Enomoto,
Kazuko Hayama,
Masako Takano,
Takeo Asakawa
Publication year - 1993
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.62.103
Subject(s) - calmodulin , cyclase , adenylate kinase , isoprenaline , beta (programming language) , chemistry , diacylglycerol kinase , enzyme activator , enzyme , biochemistry , receptor , biology , endocrinology , protein kinase c , stimulation , computer science , programming language
Adenylate cyclase purified by affinity chromatography was activated about 2.5-fold in a Ca(2+)- and calmodulin-dependent fashion. G protein beta gamma-subunits, an inhibitor in the receptor-mediated inhibition of adenylate cyclase, inhibited the purified cyclase by more than 80%. The extent of beta gamma-induced inhibition was not affected by the activation with Ca2+ and calmodulin. Moreover, the prior addition of the beta gamma-subunits to the cyclase did not prevent the subsequent activation of the enzyme by Ca2+ and calmodulin. We conclude that the beta gamma-subunits inhibit adenylate cyclase activity in a calmodulin-independent mode.