Heat shock causes transient inhibition of yeast rRNA gene transcription.

The heat-shock response in the yeast Saccharomyces cerevisiae includes transiently decreased production of the full-size pre-rRNA transcript. Here we have used quantitative hybridization of pulse-labeled RNA to cloned, immobilized sequences derived from the external transcribed spacer of yeast rDNA, coupled with determinations of relative changes in ATP pool specific activities, to show that the heat shock associated with the transfer of growing cells from 23 to 36 degrees C caused decreased transcription of the rRNA genes. This decrease in hybridization to DNA sequences complementary to the immediate 5' end of the pre-rRNA transcript suggests that the decreased transcription reflects decreased initiation of pre-rRNA transcription.