Elevated levels of σs inhibit biofilm formation in Escherichia coli: a role for the Rcs phosphorelay
Elevated levels of σs inhibit biofilm formation in Escherichia coli: a role for the Rcs phosphorelay
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DOI：
10.1099/mic.0.032722-0
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发表时间：
2009-11-01
期刊：
影响因子：
2.8
通讯作者：
Clarke, David J.
中科院分区：
文献类型：
--
作者：
Ferrieres, Lionel;Thompson, Aoife;Clarke, David J.
Res磷酸化中继由RcsC、RcsD和反应调节剂RcsB组成，并且该信号传导途径已涉及许多肠道细菌中的毒力和生物膜形成。先前显示rcsC中的突变导致大肠杆菌中有缺陷的生物膜形成[Ferrieres，L. & Clarke，D. J.（2003）Mol Microbiol 50，1665-1682]。为了确定所观察到的生物膜缺陷的分子机制，我们进行了筛选，寻找在rcsC突变体背景中恢复生物膜形成的抑制突变体。其中一个突变体被鉴定为rprA，rprA是一种编码小RNA分子的基因，该小RNA分子参与替代性sigma因子sigma（s）的转录后控制。rprA的表达受Res磷酸化介导的调节，并且由于在此背景下rprA的过表达，rcsC突变体中存在升高的sigma水平。使用不同的方法，我们已经确定sigma水平的增加是生物膜缺陷的原因。因此，在大肠杆菌中生物膜形成期间，Res磷酸化介导参与维持适当水平的σ。
The Res phosphorelay is composed of RcsC, RcsD and the response regulator RcsB, and this signalling pathway has been implicated in virulence and biofilm formation in many enteric bacteria. It was previously shown that a mutation in rcsC resulted in defective biofilm formation in Escherichia coli [Ferrieres, L. & Clarke, D. J. (2003) Mol Microbiol 50, 1665-1682]. To identify the molecular mechanisms underlying the observed biofilm defect we carried out a screen looking for suppressor mutants that restored biofilm formation in the rcsC mutant background. One of the mutants was identified to be in rprA, a gene encoding a small RNA molecule that is involved in the post-transcriptional control of the alternative sigma factor, sigma(s). The expression of rprA is regulated by the Res phosphorelay, and there are elevated sigma(s) levels present in the rcsC mutant due to the overexpression of rprA in this background. Using different approaches, we have established that the increase in sigma(s) levels is responsible for the biofilm defect. Therefore, the Res phosphorelay is involved in maintaining appropriate levels of sigma(s) during biofilm formation in E coli.