Impact of High pH Stress on Yeast Gene Expression: A Comprehensive Analysis of mRNA Turnover During Stress Responses.

Environmental alkalinisation represents a stress condition for yeast Saccharomyces cerevisiae, to which this organism responds with extensive gene expression remodelling. We show here that alkaline pH causes an overall decrease in the transcription rate (TR) and a fast destabilisation of mRNAs, followed by a more prolonged stabilisation phase. In many cases, augmented mRNA levels occur without the TR increasing, which can be attributed to mRNA stabilisation. In contrast, the reduced amount of mRNAs is contributed by both a drop in the TR and mRNA stability. A comparative analysis with other forms of stress shows that, unlike high pH stress, heat-shock, osmotic and oxidative stresses present…