RNase R is a highly unstable protein regulated by growth phase and stress

Glu Chen, Murray P. Deutscher

Research output: Contribution to journalArticlepeer-review

41 Scopus citations


RNase R is an important exoribonuclease that participates in the degradation of structured RNAs in Escherichia coli. In earlier work, it was shown that RNase R levels increase dramatically under certain stress conditions, particularly during cold shock and stationary phase. However, the regulatory processes that lead to this elevation are not well understood. We show here that the increase in RNase R in stationary phase is unaffected by the global regulators, RpoS and (p)ppGpp, and that it occurs despite a major reduction in rnr message. Rather, we find that RNase R is a highly unstable protein in exponential phase, with a half-life of ∼10 min, and that the protein is stabilized in stationary phase, leading to its relative increase. RNase R is also stabilized during cold shock and by growth in minimal medium, two other conditions that lead to its elevation. These data demonstrate that RNase R is subject to regulation by a novel, posttranslational mechanism that may have important implications for our complete understanding of RNA metabolism. Published by Cold Spring Harbor Laboratory Press.

Original languageEnglish (US)
Pages (from-to)667-672
Number of pages6
Issue number4
StatePublished - Apr 2010
Externally publishedYes


  • Cold shock
  • Exoribonuclease
  • Proteolysis
  • Stationary phase

ASJC Scopus subject areas

  • Molecular Biology


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