Heat shock-induced accumulation of translation elongation and termination factors precedes assembly of stress granules in S. cerevisiae

PLoS One. 2013;8(2):e57083. doi: 10.1371/journal.pone.0057083. Epub 2013 Feb 25.

Abstract

In response to severe environmental stresses eukaryotic cells shut down translation and accumulate components of the translational machinery in stress granules (SGs). Since they contain mainly mRNA, translation initiation factors and 40S ribosomal subunits, they have been referred to as dominant accumulations of stalled translation preinitiation complexes. Here we present evidence that the robust heat shock-induced SGs of S. cerevisiae also contain translation elongation factors eEF3 (Yef3p) and eEF1Bγ2 (Tef4p) as well as translation termination factors eRF1 (Sup45p) and eRF3 (Sup35p). Despite the presence of the yeast prion protein Sup35 in heat shock-induced SGs, we found out that its prion-like domain is not involved in the SGs assembly. Factors eEF3, eEF1Bγ2 and eRF1 were accumulated and co-localized with Dcp2 foci even upon a milder heat shock at 42°C independently of P-bodies scaffolding proteins. We also show that eEF3 accumulations at 42°C determine sites of the genuine SGs assembly at 46°C. We suggest that identification of translation elongation and termination factors in SGs might help to understand the mechanism of the eIF2α factor phosphorylation-independent repression of translation and SGs assembly.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cytoplasmic Granules / metabolism*
  • Heat-Shock Response*
  • Molecular Sequence Data
  • Peptide Elongation Factors / chemistry
  • Peptide Elongation Factors / metabolism*
  • Peptide Termination Factors / chemistry
  • Peptide Termination Factors / metabolism*
  • Ribonucleoproteins / metabolism
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Stress, Physiological

Substances

  • Peptide Elongation Factors
  • Peptide Termination Factors
  • Ribonucleoproteins
  • Saccharomyces cerevisiae Proteins

Grant support

This work was supported by the grants of the Czech Science Foundation 204/09/1924, P305/12/0480 and P305/10/P253, and RVO61388971. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.