Ribosomes regulate the stability and action of the exoribonuclease RNase R

Wenxing Liang, Murray P. Deutscher

Research output: Contribution to journalArticlepeer-review

32 Scopus citations


Ribonucleases play an important role in RNA metabolism. Yet, they are also potentially destructive enzymes whose activity must be controlled. Here we describe a novel regulatory mechanism affecting RNase R, a 3' to 5' exoribonuclease able to act on essentially all RNAs including those with extensive secondary structure. Most RNaseRis sequestered on ribosomes in growing cells where it is stable and participates in trans-translation. In contrast, the free form of the enzyme, which is deleterious to cells, is extremely unstable, turning over with a half-life of 2 min. RNaseRbinding to ribosomes is dependent on transfer-messenger RNA (tmRNA)-SmpB, nonstop mRNA, and the modified form of ribosomal protein S12. Degradation of the free form of RNase R also requires tmRNA-SmpB, but this process is independent of ribosomes, indicating two distinct roles for tmRNA-SmpB. Inhibition of RNase R binding to ribosomes leads to slower growth and a massive increase in RNA degradation. These studies indicate a previously unknown role for ribosomes in cellular homeostasis.

Original languageEnglish (US)
Pages (from-to)34791-34798
Number of pages8
JournalJournal of Biological Chemistry
Issue number48
StatePublished - Nov 29 2013

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'Ribosomes regulate the stability and action of the exoribonuclease RNase R'. Together they form a unique fingerprint.

Cite this