Hyperosmotic stress response and regulation of cell wall integrity in Saccharomyces cerevisiae share common functional aspects.
The osmosensitive phenotype of the hog1 strain is suppressed at elevated temperature. Here, we show that the same holds true for the other commonly used HOG pathway mutant strains pbs2 and sho1ssk2ssk22, but not for ste11ssk2ssk22. Instead, the ste11ssk2ssk2 strain displayed a hyperosmosensitive phenotype at 37 degrees C. This phenotype is suppressed by overexpression of LRE1, HLR1 and WSC3, all genes known to influence cell wall composition. The suppression of the temperature-induced hyperosmosensitivity by these genes prompted us to investigate the role of STE11 and other HOG pathway components in cellular integrity and, indeed, we were able show that HOG pathway mutants display sensitivity to cell wall-degrading enzymes. LRE1 and HLR1 were also shown to suppress the cell wall phenotypes associated with the HOG pathway mutants. In addition, the isolated multicopy suppressor genes suppress temperature-induced cell lysis phenotypes of PKC pathway mutants that could be an indication for shared targets of the PKC pathway and high-osmolarity response routes.
Alonso-Monge
R
R
Department of Biochemistry and Molecular Biology, IMBW, Biocentrum Amsterdam, Vrije Universiteit, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
Real
E
E
Wojda
I
I
Bebelman
J P
JP
Mager
W H
WH
Siderius
M
M
D000220:Adaptation, Biological / Q000235:genetics*; D015153:Blotting, Western; D002473:Cell Wall / Q000502:physiology*; D004789:Enzyme Activation; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal / Q000235:genetics; D004693:Glucan Endo-1,3-beta-D-Glucosidase / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D009994:Osmolar Concentration; D010641:Phenotype; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013489:Suppression, Genetic / Q000235:genetics; D013696:Temperature
D029701:Saccharomyces cerevisiae Proteins; D011493:Protein Kinase C; C088589:HOG1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; C089356:PBS2 protein, S cerevisiae; D004693:Glucan Endo-1,3-beta-D-Glucosidase