Subcellular localization and some properties of the adenylate cyclase activity of the yeast, Saccharomyces cerevisiae

Saccharomyces cerevisiae was grown in the presence of 5% (w.v) Glucose and converter to protoplasts. The total particulate material obtained from lysed protoplasts was fractionated by sucrose density gradient ultracentrifugation and the distribution of adenylate cyclase throughout the gradient determined. Adenylate cyclase activity was found to be larger associated whith intracellular particulate fractions. Little activity was found in the plasma membrane-rich fraction.The adenylate cyclase activity was found to be inhibited by F^?, pyrophosphate and aminophylline, whereas glucagon, 5-hydroxytryptamine and concanavalin A were without effect.The enzymic activity appeared to be modulated by “catabolite repressors” (glucose, fructose and α-methylglucoside) as well as by acetate. A possible role for adenylate cyclase in regulating the levels of cyclic AMP in the cell during glucose repression is suggested.