Home
This Title All WIREs
WIREs RSS Feed
How to cite this WIREs title:
WIREs RNA
Impact Factor: 6.913

RNA decay modulates gene expression and controls its fidelity

Full article on Wiley Online Library:   HTML PDF

Can't access this content? Tell your librarian.

Abstract Maintenance of cellular function relies on the expression of genetic information with high fidelity, a process in which RNA molecules form an important link. mRNAs are intermediates that define the proteome, rRNAs and tRNAs are effector molecules that act together to decode mRNA sequence information, and small noncoding RNAs can regulate mRNA half‐life and translatability. The steady‐state levels of these RNAs occur through transcriptional and posttranscriptional regulatory mechanisms, of which RNA decay pathways are integral components. RNA decay can initiate from the ends of a transcript or through endonucleolytic cleavage, and numerous factors that catalyze or promote these reactions have been identified and characterized. The rate at which decay occurs depends on RNA sequence or structural elements and usually requires the RNA to be modified in a way that allows recruitment of the decay machinery to the transcript through the binding of accessory factors or small RNAs. The major RNA decay pathways also play important roles in the quality control (QC) of gene expression. Acting in both the nucleus and cytoplasm, multiple QC factors monitor newly synthesized transcripts, or mRNAs undergoing translation, for properties essential to function, including structural integrity or the presence of complete open‐reading frames. Transcripts targeted by these surveillance mechanisms are rapidly shunted into conventional decay pathways where they are degraded rapidly to ensure that they do not interfere with the normal course of gene expression. Collectively, degradative mechanisms are important determinants of the extent of gene expression and play key roles in maintaining its accuracy. Copyright © 2010 John Wiley & Sons, Ltd. This article is categorized under: RNA Turnover and Surveillance > Regulation of RNA Stability

Eukaryotic mRNA decay pathways. (a) Deadenylation‐dependent mRNA decay pathways. The 3‐poly(A) tail is removed by the Ccr4–Not or poly(A)‐specific ribonuclease deadenylases. Following deadenylation, two mechanisms can degrade the mRNA further: either decapping‐dependent 5 → 3 decay or 3 → 5 exosome‐mediated mRNA decay. In the 5 → 3 decay pathway, the Lsm1–7p complex associates with the 3 end of the mRNA transcript and induces decapping by the Dcp1p/Dcp2p complex. The mRNA is then degraded by the 5 → 3 exoribonuclease, Xrn1p. Alternatively, the exosome can mediate 3 → 5 digestion of the deadenylated transcript. (b) Deadenylation‐independent mRNA decay pathways require recruitment of the decapping machinery. For example, in yeast, Rps28B protein interacts with Edc3p to recruit the Dcp1p/Dcp2p decapping enzyme. Following decapping, the mRNA is degraded by Xrn1p. (c) Endonuclease‐mediated mRNA decay involves an internal cleavage event in an mRNA, generating two fragments with unprotected ends. These fragments subsequently undergo digestion by Xrn1p or the exosome (reprinted with permission from Ref 5. Copyright 2007 Macmillan Publishers Ltd).

[ Normal View | Magnified View ]

Related Articles

Networks controlling mRNA decay in the immune system
No‐go decay: a quality control mechanism for RNA in translation
The role of AUF1 in regulated mRNA decay
The role of KSRP in mRNA decay and microRNA precursor maturation
The roles of TTP and BRF proteins in regulated mRNA decay
Viruses and the cellular RNA decay machinery
Bacillus subtilis mRNA decay: new parts in the toolkit
Exonucleases and endonucleases involved in polyadenylation‐ assisted RNA decay
Mechanisms of deadenylation‐dependent decay
Mechanisms of endonuclease‐mediated mRNA decay

Browse by Topic

RNA Turnover and Surveillance > Regulation of RNA Stability

Access to this WIREs title is by subscription only.

Recommend to Your
Librarian Now!

The latest WIREs articles in your inbox

Sign Up for Article Alerts