Premium
Not4‐dependent translational repression is important for cellular protein homeostasis in yeast
Author(s) -
Preissler Steffen,
Reuther Julia,
Koch Miriam,
Scior Annika,
Bruderek Michael,
Frickey Tancred,
Deuerling Elke
Publication year - 2015
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.15252/embj.201490194
Subject(s) - biology , polysome , p bodies , psychological repression , microbiology and biotechnology , repressor , translational regulation , translation (biology) , protein biosynthesis , messenger rna , ribosome , gene expression , rna , genetics , gene
Translation of aberrant or problematic mRNA s can cause ribosome stalling which leads to the production of truncated or defective proteins. Therefore, cells evolved cotranslational quality control mechanisms that eliminate these transcripts and target arrested nascent polypeptides for proteasomal degradation. Here we show that Not4, which is part of the multifunctional Ccr4–Not complex in yeast, associates with polysomes and contributes to the negative regulation of protein synthesis. Not4 is involved in translational repression of transcripts that cause transient ribosome stalling. The absence of Not4 affected global translational repression upon nutrient withdrawal, enhanced the expression of arrested nascent polypeptides and caused constitutive protein folding stress and aggregation. Similar defects were observed in cells with impaired mRNA decapping protein function and in cells lacking the mRNA decapping activator and translational repressor Dhh1. The results suggest a role for Not4 together with components of the decapping machinery in the regulation of protein expression on the mRNA level and emphasize the importance of translational repression for the maintenance of proteome integrity.