mRNA Turnover


Messenger ribonucleic acid (mRNA) decay is an important cellular mechanism for regulating gene expression in both bacteria and eukaryotes. The enzymes involved and the factors that modulate their activity have been well‐characterized. Enzymes responsible for mRNA turnover attack either the 5′ or 3′ ends (exoribonucleases) or cleave the RNA in the middle (endoribonucleases). Transcripts generally have specific modifications at their ends, such as the 5′ cap and 3′ poly(A) tail in eukaryotes, to protect them from exonucleolytic decay. RNA‐binding proteins can modulate decay rates by recruiting mRNA degradation enzymes or by altering messenger ribonucleoprotein (mRNP) conformation to favour or impede decay. Here, we describe the enzymes and regulatory factors of the mRNA decay pathways in bacteria and eukaryotes, highlighting similarities between the two. We also discuss how mRNA degradation is regulated by RNA‐binding proteins, and how mRNA turnover pathways are used to identify and degrade aberrant mRNAs.

Keywords: mRNA decay; RNA‐binding protein; decapping; deadenylase; ribonuclease

Figure 1.

(a) 5′ end dependent mRNA decay in E. coli and (b) 3′→5′ exonucleolytic decay.

Figure 2.

The deadenylation‐dependent pathway of mRNA decay in eukaryotes.


Further Reading

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Khabar KS (2005) The AU‐rich transcriptome: more than interferons and cytokines, and its role in disease. Journal of Interferon & Cytokine Research 25: 1–10.

Lin‐Chao S, Chiou NT and Schuster G (2007) The PNPase, exosome and RNA helicases as the building components of evolutionarily conserved RNA degradation machines. Journal of Biomedical Science 14: 523–532.

Marzluff WF, Wagner EJ and Duronio RJ (2008) Metabolism and regulation of canonical histone mRNAs: life without a poly(A) tail. Nature Reviews. Genetics 9: 843–854.

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Shyu AB, Wilkinson MF and van Hoof A (2008) Messenger RNA regulation: to translate or to degrade? EMBO Journal 27: 471–481.

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How to Cite close
Dickson, Alexa M, Wilusz, Carol J, and Wilusz, Jeffrey(Sep 2009) mRNA Turnover. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0000893.pub2]