Genome-wide analyses revealing a signaling network of the RcsC-YojN-RcsB phosphorelay system in Escherichia coli
Genome-wide analyses revealing a signaling network of the RcsC-YojN-RcsB phosphorelay system in Escherichia coli
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DOI：
10.1128/jb.185.19.5735-5746.2003
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发表时间：
2003-10-01
影响因子：
3.2
通讯作者：
Mizuno, T
中科院分区：
文献类型：
--
作者：
Hagiwara, D;Sugiura, M;Mizuno, T
在大肠杆菌中，荚膜柯拉酸多糖的合成通过多步RcsC-->YojN-->RcsB磷酸化来调节。通过监测一个标志性的cps：：lacZ报告基因，我们首先寻找传播RCS信号系统的生理刺激。当细胞在低温（20 ℃）下生长时，在葡萄糖作为碳源和相对高浓度的外部锌（1 mM ZnCl 2）存在下，cps：：lacZ的表达被激活。在这个Rcs信号系统中，rcsF基因产物（一种假定的外膜定位脂蛋白）也是一种重要的信号成分。基于Rcs信号传导系统的定义的信号传导途径和生理刺激，我们用微阵列进行了全基因组分析以阐明Rcs转录组（即，Rcs调节子）。32个基因被确定为推定的RCS调节子成员，这些基因包括15个新的基因，除了17个先前描述的CPS基因。使用一组37个双组分系统突变体，我们进行了替代全基因组分析。结果表明，锌响应Rcs信号系统的传播在很大程度上依赖于另一个双组分系统，PhoQ/P。考虑到PhoQ/P信号系统对外部镁的响应，我们获得的证据支持存在一个信号网络连接Res系统和PhoQ/P系统的观点，其响应于二价阳离子的外部浓度协调调节胞外多糖合成。
In Escherichia coli, capsular colanic acid polysaccharide synthesis is regulated through the multistep RcsC-->YojN-->RcsB phosphorelay. By monitoring a hallmarked cps::lacZ reporter gene, we first searched for physiological stimuli that propagate the Rcs signaling system. The expression of cps::lacZ was activated when cells were grown at a low temperature (20degreesC) in the presence of glucose as a carbon source and in the presence of a relatively high concentration of external zinc (1 mM ZnCl2). In this Rcs signaling system, the rcsF gene product (a putative outer membrane-located lipoprotein) was also an essential signaling component. Based on the defined signaling pathway and physiological stimuli for the Rcs signaling system, we conducted genome-wide analyses with microarrays to clarify the Rcs transcriptome (i.e., Rcs regulon). Thirty-two genes were identified as putative Rcs regulon members; these genes included 15 new genes in addition to 17 of the previously described cps genes. Using a set of 37 two-component system mutants, we performed alternative genome-wide analyses. The results showed that the propagation of the zinc-responsive Rcs signaling system was largely dependent on another two-component system, PhoQ/P. Considering the fact that the PhoQ/P signaling system responds to external magnesium, we obtained evidence which supports the view that there is a signaling network that connects the Res system with the PhoQ/P system, which coordinately regulates extracellular polysaccharide synthesis in response to the external concentrations of divalent cations.