Yeast translational response to high salinity: global analysis reveals regulation at multiple levels.
Genome-wide studies of steady-state mRNA levels revealed common principles underlying transcriptional changes in response to external stimuli. To uncover principles that govern other stages of the gene-expression response, we analyzed the translational response and its coordination with transcriptome changes following exposure to severe stress. Yeast cells were grown for 1 h in medium containing 1 M NaCl, which elicits a maximal but transient translation inhibition, and nonpolysomal or polysomal mRNA pools were subjected to DNA-microarray analyses. We observed a strong repression in polysomal association for most mRNAs, with no simple correlation with the changes in transcript levels. This led to an apparent accumulation of many mRNAs as a nontranslating pool, presumably waiting for recovery from the stress. However, some mRNAs demonstrated a correlated change in their polysomal association and their transcript levels (i.e., potentiation). This group was enriched with targets of the transcription factors Msn2/Msn4, and the translational induction of several tested mRNAs was diminished in an Msn2/Msn4 deletion strain. Genome-wide analysis of a strain lacking the high salinity response kinase Hog1p revealed that the group of translationally affected genes is significantly enriched with motifs that were shown to be associated with the ARE-binding protein Pub1. Since a relatively small number of genes was affected by Hog1p deletion, additional signaling pathways are likely to be involved in coordinating the translational response to severe salinity stress.
Melamed
Daniel
D
Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Pnueli
Lilach
L
Arava
Yoav
Y
D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D016681:Genome, Fungal; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D011132:Polyribosomes / Q000378:metabolism; D014176:Protein Biosynthesis; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D054712:Salinity; D012965:Sodium Chloride / Q000378:metabolism*; D015854:Up-Regulation
D029701:Saccharomyces cerevisiae Proteins; D012965:Sodium Chloride; C088589:HOG1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases