RcsB-BglJ activates the Escherichia coli leuO gene, encoding an H-NS antagonist and pleiotropic regulator of virulence determinants.
Title | RcsB-BglJ activates the Escherichia coli leuO gene, encoding an H-NS antagonist and pleiotropic regulator of virulence determinants. |
Publication Type | Journal Article |
Year of Publication | 2012 |
Authors | Stratmann, T, Pul, Ü, Wurm, R, Wagner, R, Schnetz, K |
Journal | Mol Microbiol |
Volume | 83 |
Issue | 6 |
Pagination | 1109-23 |
Date Published | 2012 Mar |
ISSN | 1365-2958 |
Keywords | Base Sequence, DNA-Binding Proteins, Escherichia coli, Escherichia coli Proteins, Fimbriae Proteins, Gene Expression Regulation, Bacterial, Molecular Chaperones, Molecular Sequence Data, Operon, Promoter Regions, Genetic, Protein Binding, Trans-Activators, Transcriptional Activation, Transcription Factors, Virulence Factors |
Abstract | The LysR-type transcription factor LeuO is involved in regulation of pathogenicity determinants and stress responses in Enterobacteriaceae, and acts as antagonist of the global repressor H-NS. Expression of the leuO gene is repressed by H-NS, and it is upregulated in stationary phase and under amino acid starvation conditions. Here, we show that the heterodimer of the FixJ/NarL-type transcription regulators RcsB and BglJ strongly activates expression of leuO and that RcsB-BglJ regulates additional loci. Activation of leuO by RcsB-BglJ is independent of the Rcs phosphorelay system. RcsB-BglJ binds to the leuO promoter region and activates one of two leuO promoters mapped in vivo. Moreover, LeuO antagonizes activation of leuO by RcsB-BglJ and acts as negative autoregulator in vivo and in vitro. Further, the H-NS paralogue StpA causes repression of leuO in addition to H-NS. Together, our data suggest a complex arrangement of regulatory elements and they indicate a feedback control mechanism of leuO expression. |
DOI | 10.1111/j.1365-2958.2012.07993.x |
Alternate Journal | Mol. Microbiol. |