Enterococcal Rgg-like regulator ElrR activates expression of the elrA operon

J Bacteriol. 2013 Jul;195(13):3073-83. doi: 10.1128/JB.00121-13. Epub 2013 May 3.

Abstract

The Enterococcus faecalis leucine-rich protein ElrA promotes virulence by stimulating bacterial persistence in macrophages and production of the interleukin-6 (IL-6) cytokine. The ElrA protein is encoded within an operon that is poorly expressed under laboratory conditions but induced in vivo. In this study, we identify ef2687 (renamed elrR), which encodes a member of the Rgg (regulator gene for glucosyltransferase) family of putative regulatory proteins. Using quantitative reverse transcription-PCR, translational lacZ fusions, and electrophoretic mobility shift assays, we demonstrate that ElrR positively regulates expression of elrA. These results correlate with the attenuated virulence of the ΔelrR strain in a mouse peritonitis model. Virulence of simple and double elrR and elrA deletion mutants also suggests a remaining ElrR-independent expression of elrA in vivo and additional virulence-related genes controlled by ElrR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Enterococcus faecalis / genetics
  • Enterococcus faecalis / metabolism*
  • Enterococcus faecalis / pathogenicity*
  • Gene Expression Regulation, Bacterial / genetics
  • Gene Expression Regulation, Bacterial / physiology*
  • Mice
  • Operon / genetics
  • Operon / physiology*
  • Virulence / genetics
  • Virulence / physiology

Substances

  • Bacterial Proteins