Heat-induced ribosome pausing triggers mRNA co-translational decay in Arabidopsis thaliana
Date
2015-04-06
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Publisher
Oxford University Press
Abstract
The reprogramming of gene expression in heat
stress is a key determinant to organism survival.
Gene expression is downregulated through translation
initiation inhibition and release of free mRNPs
that are rapidly degraded or stored. In mammals,
heat also triggers 5 -ribosome pausing preferentially
on transcripts coding for HSC/HSP70 chaperone
targets, but the impact of such phenomenon on
mRNA fate remains unknown. Here, we provide evidence
that, in Arabidopsis thaliana, heat provokes
5 -ribosome pausing leading to the XRN4-mediated
5 -directed decay of translating mRNAs. We also
show that hindering HSC/HSP70 activity at 20◦C recapitulates
heat effects by inducing ribosome pausing
and co-translational mRNA turnover. Strikingly,
co-translational decay targets encode proteins with
high HSC/HSP70 binding scores and hydrophobic
N-termini, two characteristics that were previously
observed for transcripts most prone to pausing in
animals. This work suggests for the first time that
stress-induced variation of translation elongation
rate is an evolutionarily conserved process leading
to the polysomal degradation of thousands of ‘nonaberrant’
mRNAs.
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Citation
Merret, Rémy, et al. "Heat-induced ribosome pausing triggers mRNA co-translational decay in Arabidopsis thaliana." Nucleic acids research (2015): gkv234.