Targeting the MEF2-Like Transcription Factor Smp1 by the Stress-Activated Hog1 Mitogen-Activated Protein Kinase

• DOI: 10.1128/mcb.23.1.229-237.2003
• Publication Date: 2002-12-13T21:43:47Z
• Authors: Eulàlia de Nadal; Laura Casadomé; Francesc Posas
• Keywords: Osmotic shock

Exposure ofSaccharomyces cerevisiae to increases in extracellular osmolarity activates the stress-activated Hog1 mitogen-activated protein kinase (MAPK), which is essential for cell survival upon osmotic stress.Yeast cells respond stress by inducing expression of a very large number genes, and MAPK plays critical role gene transcription stress.To understand how controls expression, we designed genetic screen isolate new factors under control identified MEF2-like factor, Smp1, as target Hog1.Overexpression SMP1 induced Hog1-dependent osmoresponsive genes such STL1, whereas smp1⌬ were defective their expression.Consistently, displayed reduced viability shock.In vivo coprecipitation phosphorylation studies showed that Smp1 interact phosphorylated manner.Hog1 vitro at C-terminal region.Phosphorylation its function, since mutant allele unable be displays impaired responses.Thus, our data indicate acts downstream Hog1, controlling subset responses MAPK.Moreover, concentrates nucleus during stationary phase, lack results lose phase.Localization depends on HOG1, consistently, hog1⌬ also this growth phase.These suggest could mediating phase.