Gene Expression Analysis of Cold and Freeze Stress in Baker's Yeast
AUTOR(ES)
Rodriguez-Vargas, Sonia
FONTE
American Society for Microbiology
RESUMO
We used mRNA differential display to assess yeast gene expression under cold or freeze shock stress conditions. We found both up- and down-regulation of genes, although repression was more common. We identified and sequenced several cold-induced genes exhibiting the largest differences. We confirmed, by Northern blotting, the specificity of the response for TPI1, which encodes triose-phosphate isomerase; ERG10, the gene for acetoacetyl coenzyme A thiolase; and IMH1, which encodes a protein implicated in protein transport. These genes also were induced under other stress conditions, suggesting that this cold response is mediated by a general stress mechanism. We determined the physiological significance of the cold-induced expression change of these genes in two baker's yeast strains with different sensitivities to freeze stress. The mRNA level of TPI1 and ERG10 genes was higher in freeze-stressed than in control samples of the tolerant strain. In contrast, both genes were repressed in frozen cells of the sensitive strain. Next, we examined the effects of ERG10 overexpression on cold and freeze-thaw tolerance. Growth of wild-type cells at 10°C was not affected by high ERG10 expression. However, YEpERG10 transformant cells exhibited increased freezing tolerance. Consistent with this, cells of an erg10 mutant strain showed a clear phenotype of cold and freeze sensitivity. These results give support to the idea that a cause-and-effect relationship between differentially expressed genes and cryoresistance exists in Saccharomyces cerevisiae and open up the possibility of design strategies to improve the freeze tolerance of baker's yeast.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=123965Documentos Relacionados
- Aquaporin Expression Correlates with Freeze Tolerance in Baker's Yeast, and Overexpression Improves Freeze Tolerance in Industrial Strains
- Analysis of sequences conferring autonomous replication in baker's yeast.
- Disruption of the CAR1 Gene Encoding Arginase Enhances Freeze Tolerance of the Commercial Baker's Yeast Saccharomyces cerevisiae
- Genetic Analysis of Haploids from Industrial Strains of Baker's Yeast
- Rox3 and Rts1 Function in the Global Stress Response Pathway in Baker's Yeast