Coordinated Regulation of Growth Genes in Saccharomyces cerevisiae

It is imperative that quiescent Saccharomyces cerevisiae cells respond rapidly to fresh medium: the cell that initiates growth and division soonest has the most progeny. Several laboratories have used DNA microarrays to identify transcripts that are altered when fresh medium is added to quiescent cells. We combined published data with our own to address several questions: Do these experiments taken together identify a core set of genes that is reproducibly affected when quiescent cells are stimulated by nutrient repletion? Is this gene set co-regulated in response to other environmental challenges? Does promoter histone occupancy correlate with the mRNA data? Despite diverse experimental designs, the data were highly correlated, generating a set of nutrient repletion transcripts. Glucose addition accounted for the response. These transcripts were also coregulated in response to diverse stresses. Promoters were associated with increased histone acetylation and decreased histone occupancy when induced, and high histone occupancy with low acetylation when repressed. The presence of RRPE and PAC promoter elements correlated with nutrient responsiveness and a dynamic pattern of histone occupancy and acetylation. Correlative evidence supports the idea that some mRNAs may be upregulated by release from sequestration in RNA-protein complexes.