Control of cell cycle in response to osmostress: lessons from yeast

To maximize the probability of survival and proliferation, cells coordinate various intracellular activities in response to changes in the extracellular environment. Eukaryotic cells transduce diverse cellular stimuli by multiple mitogen-activated protein kinase (MAPK) cascades. Exposure of cells to stress results in rapid activation of a highly conserved family of MAPKs, known as stress-activated protein kinases (SAPKs). Activation of SAPKs results in the generation of a set of adaptive responses that leads to the modulation of several aspects of cell physiology essential for cell survival, such as gene expression, translation, and morphogenesis. This chapter proposes that regulation of cell cycle progression is another general stress response critical for cell survival. Studies from yeast, both Schizosaccharomyces pombe and Saccharomyces cerevisiae, have served to start understanding how SAPKs control cell cycle progression in response to stress.