Asc1, homolog of human RACK1, prevents frameshifting in yeast by ribosomes stalled at CGA codon repeats.

Content Provider	Europe PMC
Author	Wolf, Andrew S. Grayhack, Elizabeth J.
Copyright Year	2015
Abstract	Quality control systems monitor and stop translation at some ribosomal stalls, but it is unknown if halting translation at such stalls actually prevents synthesis of abnormal polypeptides. In yeast, ribosome stalling occurs at Arg CGA codon repeats, with even two consecutive CGA codons able to reduce translation by up to 50%. The conserved eukaryotic Asc1 protein limits translation through internal Arg CGA codon repeats. We show that, in the absence of Asc1 protein, ribosomes continue translating at CGA codons, but undergo substantial frameshifting with dramatically higher levels of frameshifting occurring with additional repeats of CGA codons. Frameshifting depends upon the slow or inefficient decoding of these codons, since frameshifting is suppressed by increased expression of the native tRNAArg(ICG) that decodes CGA codons by wobble decoding. Moreover, the extent of frameshifting is modulated by the position of the CGA codon repeat relative to the translation start site. Thus, translation fidelity depends upon Asc1-mediated quality control.
ISSN	13558382
Journal	RNA
Volume Number	21
PubMed Central reference number	PMC4408800
Issue Number	5
PubMed reference number	25792604
e-ISSN	14699001
DOI	10.1261/rna.049080.114
Language	English
Publisher	Cold Spring Harbor Laboratory Press
Publisher Date	2015-03-19
Access Restriction	Open
Rights License	This article is distributed exclusively by the RNA Society for the first 12 months after the full-issue publication date (see http://rnajournal.cshlp.org/site/misc/terms.xhtml). After 12 months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/. © 2015 Wolf and Grayhack; Published by Cold Spring Harbor Laboratory Press for the RNA Society
Subject Keyword	translation stalls reading frame ribosome frameshift Asc1 Rack1
Content Type	Text
Resource Type	Article
Subject	Molecular Biology