Indole induces the expression of multidrug exporter genes in Escherichia coli

  • Hirakawa H
  • Inazumi Y
  • Masaki T
 et al. 
  • 109

    Readers

    Mendeley users who have this article in their library.
  • 160

    Citations

    Citations of this article.

Abstract

Our comprehensive expression cloning studies previously revealed that 20 intrinsic xenobiotic exporter systems are encoded in the Escherichia coli chromosome, but most of them are not expressed under normal conditions. In this study, we investigated the compounds that induce the expression of these xenobiotic exporter genes, and found that indole induces a variety of xenobiotic exporter genes including acrD, acrE, cusB, emrK, mdtA, mdtE and yceL. Indole treatment of E. coli cells confers rhodamine 6G and SDS resistance through the induction of mdtEF and acrD gene expression respectively. The induction of mdtE by indole is independent of the EvgSA two-component signal transduction system that regulates the mdtE gene, but mediated by GadX. On the other hand, the induction of acrD and mdtA was mediated by BaeSR and CpxAR, two-component systems. Interestingly, CpxAR system-mediated induction required intrinsic baeSR genes, whereas BaeSR-mediated induction was observed in the cpxAR gene-deletion mutant. BaeR and CpxR directly bound to different sequences of the acrD and mdtA promoter regions. These observations indicate that BaeR is a primary regulator, and CpxR enhances the effect of BaeR.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • Hidetada Hirakawa

  • Yoshihiko Inazumi

  • Takeshi Masaki

  • Takahiro Hirata

  • Akihito Yamaguchi

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free