A Csr-type regulatory system, including small non-coding RNAs, regulates the global virulence regulator RovA of Yersinia pseudotuberculosis through RovM.
The MarR-type regulator RovA controls expression of virulence genes of Yersinia pseudotuberculosis in response to environmental signals. Using a genetic strategy to discover components that influence rovA expression, we identified new regulatory factors with homology to components of the carbon storage regulator system (Csr). We showed that overexpression of a CsrB- or a CsrC-type RNA activates rovA, whereas a CsrA-like protein represses RovA synthesis. We further demonstrate that influence of the Csr system on rovA is indirect and occurs through control of the LysR regulator RovM, which inhibits rovA transcription. The CsrA protein had also a major influence on the motility of Yersinia, which was independent of RovM. The CsrB and CsrC RNAs are differentially expressed in Yersinia. CsrC is highly induced in complex but not in minimal media, indicating that medium-dependent rovM expression is mediated through CsrC. CsrB synthesis is generally very low. However, overexpression of the response regulator UvrY was found to activate CsrB production, which in turn represses CsrC synthesis independent of the growth medium. In summary, the post-transcriptional Csr-type components were shown to be key regulators in the co-ordinated environmental control of physiological processes and virulence factors, which are crucial for the initiation of Yersinia infections.
Heroven
Ann Kathrin
AK
Institut für Mikrobiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany.
Böhme
Katja
K
Rohde
Manfred
M
Dersch
Petra
P
D001426:Bacterial Proteins / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000502:physiology*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014774:Virulence / Q000235:genetics / Q000502:physiology*; D015011:Yersinia pseudotuberculosis / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*
D001426:Bacterial Proteins; C107123:CsrB RNA, E coli; D012329:RNA, Bacterial; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D016601:RNA-Binding Proteins; C405626:RovA protein, Yersinia; C517503:RovM protein, Yersinia pseudotuberculosis; D014157:Transcription Factors