title: Acclimation of Saccharomyces cerevisiae to low temperature: a chemostat-based transcriptome analysis.
abstract: Effects of suboptimal temperatures on transcriptional regulation in yeast have been extensively studied in batch cultures. To eliminate indirect effects of specific growth rates that are inherent to batch-cultivation studies, genome-wide transcriptional responses to low temperatures were analyzed in steady-state chemostats, grown at a fixed specific growth rate (0.03 h(-1)). Although in vivo metabolic fluxes were essentially the same in cultures grown at 12 and at 30 degrees C, concentrations of the growth-limiting nutrients (glucose or ammonia) were higher at 12 degrees C. This difference was reflected by transcript levels of genes that encode transporters for the growth-limiting nutrients. Several transcriptional responses to low temperature occurred under both nutrient-limitation regimes. Increased transcription of ribosome-biogenesis genes emphasized the importance of adapting protein-synthesis capacity to low temperature. In contrast to observations in cold-shock and batch-culture studies, transcript levels of environmental stress response genes were reduced at 12 degrees C. Transcription of trehalose-biosynthesis genes and intracellular trehalose levels indicated that, in contrast to its role in cold-shock adaptation, trehalose is not involved in steady-state low-temperature adaptation. Comparison of the chemostat-based transcriptome data with literature data revealed large differences between transcriptional reprogramming during long-term low-temperature acclimation and the transcriptional responses to a rapid transition to low temperature.
authors.affiliation: Department of Biotechnology, Delft University of Technology, 2628 BC Delft, The Netherlands.
authors.forename: Siew Leng
authors.initials: SL
authors.lastname: Tai
authors.forename: Pascale
authors.initials: P
authors.lastname: Daran-Lapujade
authors.forename: Michael C
authors.initials: MC
authors.lastname: Walsh
authors.forename: Jack T
authors.initials: JT
authors.lastname: Pronk
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Daran
mesh_terms: D000064:Acclimatization; D000693:Anaerobiosis; D050260:Carbohydrate Metabolism; D003080:Cold Temperature; D015536:Down-Regulation; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D014176:Protein Biosynthesis; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology*; D015854:Up-Regulation