Small Regulatory RNAs in the Enterobacterial Response to Envelope Damage and Oxidative Stress

Microbiol Spectr. 2018 Jul;6(4):10.1128/microbiolspec.RWR-0022-2018. doi: 10.1128/microbiolspec.RWR-0022-2018.

Abstract

The ability of bacteria to thrive in diverse habitats and to adapt to ever-changing environmental conditions relies on the rapid and stringent modulation of gene expression. It has become evident in the past decade that small regulatory RNAs (sRNAs) are central components of networks controlling the bacterial responses to stress. Functioning at the posttranscriptional level, sRNAs base-pair with cognate mRNAs to alter translation, stability, or both to either repress or activate the targeted transcripts; the RNA chaperone Hfq participates in stabilizing sRNAs and in promoting pairing between target and sRNA. In particular, sRNAs act at the heart of crucial stress responses, including those dedicated to overcoming membrane damage and oxidative stress, discussed here. The bacterial cell envelope is the outermost protective barrier against the environment and thus is constantly monitored and remodeled. Here, we review the integration of sRNAs into the complex networks of several major envelope stress responses of Gram-negative bacteria, including the RpoE (σE), Cpx, and Rcs regulons. Oxidative stress, caused by bacterial respiratory activity or induced by toxic molecules, can lead to significant damage of cellular components. In Escherichia coli and related bacteria, sRNAs also contribute significantly to the function of the RpoS (σS)-dependent general stress response as well as the specific OxyR- and SoxR/S-mediated responses to oxidative damage. Their activities in gene regulation and crosstalk to other stress-induced regulons are highlighted.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bacteria / metabolism
  • Bacterial Proteins / metabolism
  • Enterobacteriaceae / metabolism*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / metabolism
  • Gene Expression Regulation, Bacterial*
  • Oxidative Stress / physiology*
  • RNA, Bacterial / metabolism*
  • RNA, Messenger / metabolism
  • RNA, Small Untranslated / metabolism
  • Regulon
  • Repressor Proteins / metabolism
  • Sigma Factor / metabolism
  • Stress, Physiological
  • Trans-Activators / metabolism
  • Transcription Factors / metabolism

Substances

  • Bacterial Proteins
  • Escherichia coli Proteins
  • RNA, Bacterial
  • RNA, Messenger
  • RNA, Small Untranslated
  • Repressor Proteins
  • Sigma Factor
  • Trans-Activators
  • Transcription Factors
  • oxyR protein, E coli
  • sigma factor KatF protein, Bacteria
  • SoxR protein, Bacteria
  • SoxS protein, E coli