The two-component network and the general stress sigma factor RpoS (σS) in Escherichia coli
The two-component network and the general stress sigma factor RpoS (σS) in Escherichia coli
复制标题
DOI：
10.1007/978-0-387-78885-2_4
复制
发表时间：
2008-01-01
期刊：
影响因子：
--
通讯作者：
Hengge, Regine
中科院分区：
文献类型：
--
作者：
Hengge, Regine
一般应力σ因子RpoS（σ（S））是在进入稳定期期间和响应于多种应力条件而产生的。RpoS在转录、翻译、蛋白水解和蛋白活性水平上受到调节。RpoS控制中的一个关键因素是双组分反应调节剂RssB，其充当ClpXP介导的RpoS蛋白水解的直接识别和靶向因子。RssB的一个主要但不是唯一的磷酸供体是复合组氨酸传感器激酶ArcB。ArcB还通过磷酸化反应调节因子ArcA来协调RpoS蛋白水解与rpoS转录，ArcA除了控制大的调节子之外，还充当rpoS的转录抑制因子。ArcB活性取决于呼吸链的氧化还原状态，其将RpoS控制与能量供应和可用的呼吸电子受体之间的平衡联系起来。此外，BarA/UvrY和Rcs磷酸化系统可以分别激活rpoS转录和翻译。这些系统参与运动性，生物膜形成和/或毒力的控制，这表明进一步研究RpoS在这些生理功能中的潜在作用可能是有益的。
The general stress sigma factor RpoS (sigma(S)) is induced during entry into stationary phase and in response to multiple stress conditions. RpoS is regulated at the levels of transcription, translation, proteolysis and protein activity. A key factor in RpoS control is the two-component response regulator RssB, which acts as a direct recognition and targeting factor for ClpXP-mediated RpoS proteolysis. A major, but not the only phosphodonor for RssB is the complex histidine sensor kinase ArcB. ArcB coordinates RpoS proteolysis with rpoS transcription by also phosphorylating the response regulator ArcA, which besides controlling a large regulon, also acts as a transcriptional repressor for rpoS. ArcB activity depends on the redox state of the respiratory chain, which links RpoS control to the balance between energy supply and available respiratory electron acceptor. In addition, the BarA/UvrY and Rcs phosphorelay systems can activate rpoS transcription and translation, respectively. These systems are involved in the control of motility, biofilm formation and/or virulence, suggesting that further studying a potential role of RpoS in these physiological functions may be rewarding.