Publication Date:
2010-09-14
Description:
Messenger RNA lacking stop codons ('non-stop mRNA') can arise from errors in gene expression, and encode aberrant proteins whose accumulation could be deleterious to cellular function. In bacteria, these 'non-stop proteins' become co-translationally tagged with a peptide encoded by ssrA/tmRNA (transfer-messenger RNA), which signals their degradation by energy-dependent proteases. How eukaryotic cells eliminate non-stop proteins has remained unknown. Here we show that the Saccharomyces cerevisiae Ltn1 RING-domain-type E3 ubiquitin ligase acts in the quality control of non-stop proteins, in a process that is mechanistically distinct but conceptually analogous to that performed by ssrA: Ltn1 is predominantly associated with ribosomes, and it marks nascent non-stop proteins with ubiquitin to signal their proteasomal degradation. Ltn1-mediated ubiquitylation of non-stop proteins seems to be triggered by their stalling in ribosomes on translation through the poly(A) tail. The biological relevance of this process is underscored by the finding that loss of Ltn1 function confers sensitivity to stress caused by increased non-stop protein production. We speculate that defective protein quality control may underlie the neurodegenerative phenotype that results from mutation of the mouse Ltn1 homologue Listerin.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2988496/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2988496/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bengtson, Mario H -- Joazeiro, Claudio A P -- R01 GM083060/GM/NIGMS NIH HHS/ -- R01 GM083060-03/GM/NIGMS NIH HHS/ -- R01GM083060/GM/NIGMS NIH HHS/ -- England -- Nature. 2010 Sep 23;467(7314):470-3. doi: 10.1038/nature09371. Epub 2010 Sep 12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cell Biology, The Scripps Research Institute, CB168, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20835226" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Codon, Terminator/genetics
;
Mice
;
Models, Biological
;
Peptide Chain Termination, Translational
;
Polylysine/biosynthesis/metabolism
;
Proteasome Endopeptidase Complex/metabolism
;
Protein Binding
;
Protein Biosynthesis/*physiology
;
Ribosomes/*enzymology/*metabolism
;
Saccharomyces cerevisiae/cytology/enzymology/genetics/metabolism
;
Saccharomyces cerevisiae Proteins/genetics/*metabolism
;
Stress, Physiological
;
Ubiquitin/metabolism
;
Ubiquitin-Protein Ligases/deficiency/genetics/*metabolism
;
*Ubiquitination
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
