In vitro activation of the Saccharomyces cerevisiae Ras/adenylate cyclase system by glucose and some of its analogues

Using crude membrane preparations of Saccharomyces cerevisiae, we have demonstrated that glucose and glucose analogues which are not efficiently phosphorylated activate the guanine nucleotide-dependent adenylate cyclase in vitro. The activation appears to be mediated by the Ras proteins. Moreover, data are presented indicating that glucose and its analogues activate adenylate cyclase by stimulating the exchange of guanine nucleotides at its regulatory component. Thus, it has been possible to show the action of a physiological effector on the nucleotide exchange reaction in a member of the ras superfamily