title: Hsp90 regulates nongenetic variation in response to environmental stress.
abstract: Nongenetic cell-to-cell variability often plays an important role for the survival of a clonal population in the face of fluctuating environments. However, the underlying mechanisms regulating such nongenetic heterogeneity remain elusive in most organisms. We report here that a clonal yeast population exhibits morphological heterogeneity when the level of Hsp90, a molecular chaperone, is reduced. The morphological heterogeneity is driven by the dosage of Cdc28 and Cla4, a key regulator of septin formation. Low Hsp90 levels reduce Cla4 protein stability and cause a subpopulation of cells to switch to a filamentous form that has been previously suggested to be beneficial under certain hostile environments. Moreover, Hsp90-dependent morphological heterogeneity can be induced by environmental stress and is conserved across diverse yeast species. Our results suggest that Hsp90 provides an evolutionarily conserved mechanism that links environmental stress to the induction of morphological diversity.
authors: Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan.
authors: Yu-Ying
authors: YY
authors: Hsieh
authors: Po-Hsiang
authors: PH
authors: Hung
authors: Jun-Yi
authors: JY
authors: Leu
mesh_terms: D017489:CDC28 Protein Kinase, S cerevisiae / Q000378:metabolism; D015536:Down-Regulation; D019143:Evolution, Molecular; D015966:Gene Expression Regulation, Fungal; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018869:Heat-Shock Response; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D055550:Protein Stability; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D058112:Septins / Q000378:metabolism; D013045:Species Specificity; D020068:Zygosaccharomyces / Q000235:genetics / Q000378:metabolism
chemical_list: C074510:HSP82 protein, S cerevisiae; D018841:HSP90 Heat-Shock Proteins; D029701:Saccharomyces cerevisiae Proteins; C095212:CLA4 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; D017489:CDC28 Protein Kinase, S cerevisiae; D058112:Septins