Article

Dom34:Hbs1 Plays a General Role in Quality-Control Systems by Dissociation of a Stalled Ribosome at the 3′ End of Aberrant mRNA

Graduate School of Pharmaceutical Science, Tohoku University, Sendai, Japan.
Molecular cell (Impact Factor: 14.46). 04/2012; 46(4):518-29. DOI: 10.1016/j.molcel.2012.03.013
Source: PubMed

ABSTRACT Translation arrest leads to an endonucleolytic cleavage of mRNA that is termed no-go decay (NGD). It has been reported that the Dom34:Hbs1 complex stimulates this endonucleolytic cleavage of mRNA induced by translation arrest in vivo and dissociates subunits of a stalled ribosome in vitro. Here we report that Dom34:Hbs1 dissociates the subunits of a ribosome that is stalled at the 3' end of mRNA in vivo, and has a crucial role in both NGD and nonstop decay. Dom34:Hbs1-mediated dissociation of a ribosome that is stalled at the 3' end of mRNA is required for degradation of a 5'-NGD intermediate. Dom34:Hbs1 facilitates the decay of nonstop mRNAs from the 3' end by exosomes and is required for the complete degradation of nonstop mRNA decay intermediates. We propose that Dom34:Hbs1 stimulates degradation of the 5'-NGD intermediate and of nonstop mRNA by dissociating the ribosome that is stalled at the 3' end of the mRNA.

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Available from: Toshifumi Inada, Apr 01, 2014
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    • "Nonsense-mediated mRNA decay (NMD) is one of three conserved eukaryotic surveillance pathways ensuring mRNA quality control in the cytoplasm [1] [2] [3] [4]. NMD is activated by mechanistic differences between normal and premature translation termination and utilizes three conserved factors (Upf1, Upf2, and Upf3) [5] [6] [7] to couple nonsense codon recognition to the release factors (eRF1 and eRF3), the ribosome, and the mRNA decapping complex [8] [9] [10] [11] [12] [13] [14]. "
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    Journal of Molecular Biology 09/2014; 426(22). DOI:10.1016/j.jmb.2014.09.015 · 4.33 Impact Factor
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    • "In our study, we split ribosomes using Pelota, Hbs1, and ABCE1, factors identified to recycle empty and stalled 80S ribosomes in earlier in vitro experiments (Pisareva et al., 2011). The physiologic targets of these factors are only now emerging and clearly include ribosomes at the end of truncated mRNAs (Guydosh and Green, 2014; Tsuboi et al., 2012). Because we employed a truncated mRNA in our experiments, the use of Pelota/Hbs1/ABCE1 is appropriate and physiologically relevant. "
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    • "The level of translated GFP- Rz was increased in ltn1D or ltn1Dnot4D mutant cells, but peptidyl-tRNA was barely detectable, even in the mutants (Fig. 1D), suggesting that peptidyltRNA on stalled 80S ribosomes might not be a substrate for the ligase, as previously proposed (Bengtson & Joazeiro 2010; Brandman et al. 2012). Dom34: Hbs1 is known to be required for the dissociation of ribosomes that are stalled at the 3′ end of GFP-Rz mRNA and for peptide release from tRNA in vivo (Tsuboi et al. 2012). To examine whether peptidyltRNA was stabilized in ltn1Ddom34D mutant cells, polysome analysis followed by NuPAGE and Western blotting with an anti-GFP antibody was carried out. "
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