Post-transcriptional regulation of gene expression in yeast under ethanol stress.

The selective export of mRNA from the nucleus plays an important role in the regulation of yeast gene expression under ethanol-stressed conditions, and it has been clarified that expression of the transcriptionally activated HSP (heat-shock protein) genes are inhibited in the mRNA processing and export steps. In actual alcoholic fermentation, during the late brewing process for wine in which the ethanol concentration has been increased, the export of bulk poly(A)+ (polyadenylated) mRNA is blocked and protein synthesis is considerably repressed. These observations clearly suggest that variation in the mRNA level is not necessarily reflected in the variation of the protein level in yeast cells during the brewing process. The present minireview outlines the regulation of yeast gene expression at the mRNA-processing and nuclear-export steps under ethanol-stressed conditions, highlighting their usefulness in the brewing industry.