LITHIUM IN THE MATING RESPONSE AND CELL-CYCLE OF SACCHAROMYCES-CEREVISIAE

Studies with Lit, an inhibitor of phosphoinositide metabolism, demonst rated that an early response of Saccharomyces cerevisiae to a-factor p heromone was negatively affected by this cation. This was monitored by the production of beta-galactosidase from a reporter construct contai ning the promoter region of the yeast STE3 gene and the coding region of the E. coli LacZ gene. Growth and progression through the cell cycl e were also affected by Li+ and analysis of budded/unbudded ratios rev ealed that Lit caused yeast cells to arrest in G1. These data provide support for the role of inositol phosphates in the mating response and cell cycle of Saccharomyces cerevisiae. (C) 1995 Academic Press, Inc.