The activation of stress protein kinases is essential for proper cellular adaptation to external stimuli. In the yeast Saccharomyces cerevisiae, an increase of extra cellular osmolarity activates the MAP kinase pathway of Hog1, which is derived from a complex adaptive response. Researchers at the Universitat Pompeu Fabric and Universitat International de Catalonia have characterized various aspects of the response, revealing that one of the protective mechanisms induced Hog1 arrests the cell cycle in G1 phase, through a twofold process that ends with inhibition of CDK (cyclin dependent kinase), a key enzyme that allows cell cycle progression. (more...)