Yeast translational response to high salinity: Global analysis reveals regulation at multiple levels

  1. Daniel Melamed,
  2. Lilach Pnueli, and
  3. Yoav Arava
  1. Faculty of Biology, Technion—Israel Institute of Technology, Haifa 32000, Israel

Abstract

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.

Keywords

Footnotes

  • Reprint requests to: Yoav Arava, Faculty of Biology, Technion—Israel Institute of Technology, Haifa 32000, Israel; e-mail: arava{at}tx.technion.ac.il; fax: 972-4-822-5153.

  • Article published online ahead of print. Article and publication date are at http://www.rnajournal.org/cgi/doi/10.1261/rna.864908.

    • Received October 7, 2007.
    • Accepted March 27, 2008.
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