Defining a role for Hfq in Gram-positive bacteria: evidence for Hfq-dependent antisense regulation in Listeria monocytogenes

Nucleic Acids Res. 2010 Jan;38(3):907-19. doi: 10.1093/nar/gkp1081. Epub 2009 Nov 26.

Abstract

Small trans-encoded RNAs (sRNAs) modulate the translation and decay of mRNAs in bacteria. In Gram-negative species, antisense regulation by trans-encoded sRNAs relies on the Sm-like protein Hfq. In contrast to this, Hfq is dispensable for sRNA-mediated riboregulation in the Gram-positive species studied thus far. Here, we provide evidence for Hfq-dependent translational repression in the Gram-positive human pathogen Listeria monocytogenes, which is known to encode at least 50 sRNAs. We show that the Hfq-binding sRNA LhrA controls the translation and degradation of its target mRNA by an antisense mechanism, and that Hfq facilitates the binding of LhrA to its target. The work presented here provides the first experimental evidence for Hfq-dependent riboregulation in a Gram-positive bacterium. Our findings indicate that modulation of translation by trans-encoded sRNAs may occur by both Hfq-dependent and -independent mechanisms, thus adding another layer of complexity to sRNA-mediated riboregulation in Gram-positive species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Pairing
  • Base Sequence
  • Gene Expression Regulation, Bacterial*
  • Host Factor 1 Protein / genetics
  • Host Factor 1 Protein / metabolism
  • Host Factor 1 Protein / physiology*
  • Listeria monocytogenes / genetics*
  • Listeria monocytogenes / metabolism
  • Molecular Sequence Data
  • Mutation
  • Peptide Chain Initiation, Translational
  • Protein Biosynthesis
  • RNA Stability
  • RNA, Antisense / chemistry*
  • RNA, Antisense / genetics
  • RNA, Messenger / chemistry
  • RNA, Messenger / metabolism
  • RNA, Untranslated / chemistry*
  • RNA, Untranslated / genetics

Substances

  • Host Factor 1 Protein
  • RNA, Antisense
  • RNA, Messenger
  • RNA, Untranslated