A genomic approach to defining the ethanol stress response in the yeast Saccharomyces cerevisiae

Gene array analysis was used to study changes in gene expression at two time intervals, one and three hours, during the acclimatisation of yeast to 5% (v/v) ethanol stress. Following one hour of ethanol exposure, 100 genes showed a greater than 3-fold increase in transcript level and 274 gene transcripts decreased greater than 3-fold. Functional categories of genes up-regulated at this time point included those associated with general stress responses, energy utilisation, transport mechanisms, cell surface interactions and lipid metabolism. Following three hours of exposure to ethanol stress the number of up-regulated genes had declined to 14 and these were associated with energy utilisation, general stress responses and vacuolar functions. Only 7 of these 14 genes were common to the one-hour time point. The number of down-regulated genes at three hours had decreased to 99. An analysis of promoter sequences in the up- and down-regulated genes is also presented here. The data generated for this work is compared to that of a previous study of the 'early' response to ethanol stress and while there is commonality across the two studies there are important differences.