Regulation of Escherichia coli cell envelope proteins involved in protein folding and degradation by the Cpx two-component system
Regulation of Escherichia coli cell envelope proteins involved in protein folding and degradation by the Cpx two-component system
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DOI：
10.1101/gad.11.9.1169
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发表时间：
1997-05-01
影响因子：
10.5
通讯作者：
Beckwith, J
中科院分区：
文献类型：
--
作者：
Pogliano, J;Lynch, AS;Beckwith, J
我们发现，大肠杆菌的双组分信号转导系统，CpxA-CpxR，控制编码细胞包膜蛋白参与蛋白质折叠和降解的基因的表达。这些发现基于三条证据。首先，Cpx途径的激活诱导DsbA（二硫键形成所需）和DegP（主要周质蛋白酶）的合成增加5至10倍。第二，使用电泳迁移率变化和DNA酶I保护测定，我们已经表明，磷酸化CpxR结合到元件上游的转录起始位点的dsbA，degP和ppiA（rotA），后者编码的肽基脯氨酰顺/反异构酶。第三，我们已经证明，当Cpx通路被激活时，所有三个基因dsbA、degP和ppiA的体内转录增加。我们已经确定了一个推定的CpxR的共识结合位点，发现上游的一些其他E。coli基因。这些发现表明可能存在广泛的Cpx调节子，包括由sigma（70）和sigma（E）转录的基因，其编码参与蛋白质折叠以及其他细胞功能的因子。
We show that the two-component signal transduction system of Escherichia coli, CpxA-CpxR, controls the expression of genes encoding cell envelope proteins involved in protein folding and degradation. These findings are based on three lines of evidence. First, activation of the Cpx pathway induces 5- to 10-fold the synthesis of DsbA, required for disulfide bond formation, and DegP, a major periplasmic protease. Second, using electrophoretic mobility shift and DNase I protection assays, we have shown that phosphorylated CpxR binds to elements upstream of the transcription start sites of dsbA, degP, and ppiA (rotA), the latter coding for a peptidyl-prolyl cis/trans isomerase. Third, we have demonstrated increased in vivo transcription of all three genes, dsbA, degP, and ppiA, when the Cpx pathway is activated. We have identified a putative CpxR consensus binding site that is found upstream of a number of other E. coli genes. These findings suggest a potentially extensive Cpx regulon including genes transcribed by sigma(70) and sigma(E), which encode factors involved in protein folding as well as other cellular functions.