ppGpp regulation of RpoS degradation via anti-adaptor protein IraP
ppGpp regulation of RpoS degradation via anti-adaptor protein IraP
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DOI：
10.1073/pnas.0705561104
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发表时间：
2007-07-31
影响因子：
11.1
通讯作者：
Gottesman, Susan
中科院分区：
文献类型：
--
作者：
Bougdour, Alexandre;Gottesman, Susan
IraP是一种小蛋白，它通过阻断RssB（一种用于σS降解的衔接蛋白）的作用来干扰σS（RpoS）向ClpXP蛋白酶的传递。先前已表明IraP在磷酸盐饥饿期间介导σS的稳定。在此，我们表明iraP是响应磷酸盐饥饿而转录的；这种反应是由ppGpp介导的。iraP启动子受ppGpp正调控，这取决于iraP启动子的鉴别区域。对磷酸盐饥饿的感知需要SpoT但不需要RelA。这些结果证明了ppGpp正调控的一个靶点，并表明细胞利用ppGpp介导多种饥饿反应在一定程度上是通过调节σS水平来实现的。
lraP is a small protein that interferes with the delivery of os (RpoS) to the ClpXP protease by blocking the action of RssB, an adaptor protein for os degradation. lraP was previously shown to mediate stabilization of os during phosphate starvation. Here, we show that iraP is transcribed in response to phosphate starvation; this response is mediated by ppGpp. The iraP promoter is positively regulated by ppGpp, dependent on the discriminator region of the iraP promoter. Sensing of phosphate starvation requires SpoT but not RelA. The results demonstrate a target for positive regulation by ppGpp and suggest that the cell use of ppGpp to mediate a variety of starvation responses operates in part by modulating sigma(s) levels.