Nitrogen Starvation‐induced Phosphorylation of Gpa2 Acts as a Molecular Switch in Promoting Sporulation

Abstract

G proteins are important molecular switches that facilitate the transmission of a variety of signals from outside to the inside of the cells. G proteins are highly conserved, which allows studying their mechanisms of regulation in model organisms such as the budding yeast Saccharomyces cerevisiae. Gpa2 is a yeast G alpha protein that functions in the nutrient signaling pathway. Through the usage of phos‐tag, we found that Gpa2 protein undergoes phosphorylation and its level of phosphorylation is markedly increased upon nitrogen starvation. Gpa2 interacts with glycogen synthase kinase (GSK), and disrupting GSK activity diminishes the level of Gpa2 phosphorylation. Functionally, phosphorylation enhances plasma membrane localization of Gpa2 and promotes sporulation in response to nutrient deprivation condition. Together, our study reveals a mechanism by which GSK‐and nutrient‐dependent phosphorylation of Gpa2 serves as a molecular switch that regulates sporulation in yeast.Support or Funding InformationWe thank Drs. Claudina Rodrigues‐Pousada, Henrik G. Dohlman, and Jeremy Thorner for generously providing strains, plasmids and antibodies.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.