BACKGROUND: In response to various stressful situations, including diauxic conditions, the Msn2 and Msn4 transcription factors induce STRE-mediated gene expression of many stress responsive genes in Saccharomyces cerevisiae. This is called the general stress response. The whi2 cells in the stationary phase are smaller than wild-type cells. RESULTS: Here we demonstrate that STRE-mediated gene expression in whi2 cells is reduced to half of that in the wild-type cells under various stress conditions. It is also delayed for several hours when the mutant cells enter the stationary phase. Using the two-hybrid system, we isolated a WHI2-interacting gene, PSR1, which is one of the redundant genes encoding plasma membrane phosphatases. whi2 and psr1 psr2 mutants had similar phenotypes, including reduced STRE-mediated gene expression, higher sensitivity to sodium ions and heat shock, and hyper-phosphorylation of Msn2. The phosphatase activity of Psr1 was necessary for the full activation of STRE-mediated gene expression. Furthermore, both Psr1 and Msn2 were co-immunoprecipitated with Whi2. CONCLUSIONS: Thus, Whi2 and its binding partner, Psr1-phosphatase, are required for a full activation of the general stress response, possibly through the dephosphorylation of Msn2. These results may explain why stationary phase whi2 cells are small.
BACKGROUND: In response to various stressful situations, including diauxic conditions, the Msn2 and Msn4 transcription factors induce STRE-mediated gene expression of many stress responsive genes in Saccharomyces cerevisiae. This is called the general stress response. The whi2 cells in the stationary phase are smaller than wild-type cells. RESULTS: Here we demonstrate that STRE-mediated gene expression in whi2 cells is reduced to half of that in the wild-type cells under various stress conditions. It is also delayed for several hours when the mutant cells enter the stationary phase. Using the two-hybrid system, we isolated a WHI2-interacting gene, PSR1, which is one of the redundant genes encoding plasma membrane phosphatases. whi2 and psr1psr2 mutants had similar phenotypes, including reduced STRE-mediated gene expression, higher sensitivity to sodium ions and heat shock, and hyper-phosphorylation of Msn2. The phosphatase activity of Psr1 was necessary for the full activation of STRE-mediated gene expression. Furthermore, both Psr1 and Msn2 were co-immunoprecipitated with Whi2. CONCLUSIONS: Thus, Whi2 and its binding partner, Psr1-phosphatase, are required for a full activation of the general stress response, possibly through the dephosphorylation of Msn2. These results may explain why stationary phase whi2 cells are small.
Authors: Jolanda van Leeuwen; Carles Pons; Joseph C Mellor; Takafumi N Yamaguchi; Helena Friesen; John Koschwanez; Mojca Mattiazzi Ušaj; Maria Pechlaner; Mehmet Takar; Matej Ušaj; Benjamin VanderSluis; Kerry Andrusiak; Pritpal Bansal; Anastasia Baryshnikova; Claire E Boone; Jessica Cao; Atina Cote; Marinella Gebbia; Gene Horecka; Ira Horecka; Elena Kuzmin; Nicole Legro; Wendy Liang; Natascha van Lieshout; Margaret McNee; Bryan-Joseph San Luis; Fatemeh Shaeri; Ermira Shuteriqi; Song Sun; Lu Yang; Ji-Young Youn; Michael Yuen; Michael Costanzo; Anne-Claude Gingras; Patrick Aloy; Chris Oostenbrink; Andrew Murray; Todd R Graham; Chad L Myers; Brenda J Andrews; Frederick P Roth; Charles Boone Journal: Science Date: 2016-11-04 Impact factor: 47.728