Transcriptome profiling of Saccharomyces cerevisiae during a transition from fermentative to glycerol-based respiratory growth reveals extensive metabolic and structural remodeling.

Transcriptome analyses using a wild-type strain of Saccharomyces cerevisiae were performed to assess the overall pattern of gene expression during the transition from glucose-based fermentative to glycerol-based respiratory growth. These experiments revealed a complex suite of metabolic and structural changes associated with the adaptation process. Alterations in gene expression leading to remodeling of various membrane transport systems and the cortical actin cytoskeleton were observed. Transition to respiratory growth was accompanied by alterations in transcript patterns demonstrating not only a general stress response, as seen in earlier studies, but also the oxidative and osmotic stress responses. In some contrast to earlier studies, these experiments identified modulation of expression for many genes specifying transcription factors during the transition to glycerol-based growth. Importantly and unexpectedly, an ordered series of changes was seen in transcript levels from genes encoding components of the TFIID, SAGA (Spt-Ada-Gcn5-Acetyltransferase), and SLIK (Saga LIKe) complexes and all three RNA polymerases, suggesting a modulation of structure for the basal transcriptional machinery during adaptation to respiratory growth. In concert with data given in earlier studies, the results presented here highlight important aspects of metabolic and other adaptations to respiratory growth in yeast that are common to utilization of multiple carbon sources. Importantly, they also identify aspects specific to adaptation of this organism to growth on glycerol as sole carbon source.