Infrequent Translation of a Nonsense Codon Is Sufficient to Decrease mRNA Level
AUTOR(ES)
Buzina, Alla
FONTE
The American Society for Cell Biology
RESUMO
In many organisms nonsense mutations decrease the level of mRNA. In the case of mammalian cells, it is still controversial whether translation is required for this nonsense-mediated RNA decrease (NMD). Although previous analyzes have shown that conditions that impede translation termination at nonsense codons also prevent NMD, the residual level of termination was unknown in these experiments. Moreover, the conditions used to impede termination might also have interfered with NMD in other ways. Because of these uncertainties, we have tested the effects of limiting translation of a nonsense codon in a different way, using two mutations in the immunoglobulin μ heavy chain gene. For this purpose we exploited an exceptional nonsense mutation at codon 3, which efficiently terminates translation but nonetheless maintains a high level of μ mRNA. We have shown 1) that translation of Ter462 in the double mutant occurs at only ∼4% the normal frequency, and 2) that Ter462 in cis with Ter3 can induce NMD. That is, translation of Ter462 at this low (4%) frequency is sufficient to induce NMD.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=25184Documentos Relacionados
- Intranuclear degradation of nonsense codon-containing mRNA
- Efficient initiation of mammalian mRNA translation at a CUG codon.
- Recognition of Yeast mRNAs as “Nonsense Containing” Leads to Both Inhibition of mRNA Translation and mRNA Degradation: Implications for the Control of mRNA Decapping
- The N-terminal half of the influenza virus NS1 protein is sufficient for nuclear retention of mRNA and enhancement of viral mRNA translation.
- Translation repression by GLD-1 protects its mRNA targets from nonsense-mediated mRNA decay in C. elegans