The effects of Gpr1 and Gpa2 on the mating pathway in <i>Saccharomyces cerevisiae</i>

Abstract

Nutrient sensing and mating are clearly linked in a number of different fungal species. The mechanisms by which these two processes interact appear to differ in different species. We have observed that glucose sensing and mating are closely linked in Saccharomyces cerevisiae, with disruptions in the glucose sensing pathway causing reduction in mating pathway activity. In this study we sought to determine the mechanisms by which this reduction occurs. In a series of gene replacement experiments we have shown that overexpressing the mating receptor in glucose receptor (Gpr1) deficient cells restores the mating pathway. Likewise, overexpression of the g protein associated with glucose sensing, Gpa2, is able to restore the mating pathway in Gpr1蜐 cells. These effects seem to be independent of the activity of the g‐protein. Dominant negative effects were seen with some modified forms of Gpr1. We propose a mechanism of interaction that involves the formation of a complex involving potentially Ste2, Gpr1, Gpa2, and Gpa1. This research was funded by the NSF, Project #0952519