HySP26 gene transcription is strongly induced during Saccharomyces cerevisiae growth at low pH.

During exponential growth of Saccharomyces cerevisiae at the inhibitory pH 2.5, the transcription of the major small-heat-shock-protein-encoding gene HSP26 was strongly induced while at the optimal pH 5.0, the mRNA levels from the HSP26 gene were undetectable. When yeast cells entered the stationary phase of growth at pH 5.0, transcription was dramatically enhanced and the level of the HSP26 transcripts reached similar values in stationary cells grown at optimal or inhibitory low pH.