THE CPX 2-COMPONENT SIGNAL-TRANSDUCTION PATHWAY OF ESCHERICHIA-COLI REGULATES TRANSCRIPTION OF THE GENE SPECIFYING THE STRESS-INDUCIBLE PERIPLASMIC PROTEASE, DEGP
THE CPX 2-COMPONENT SIGNAL-TRANSDUCTION PATHWAY OF ESCHERICHIA-COLI REGULATES TRANSCRIPTION OF THE GENE SPECIFYING THE STRESS-INDUCIBLE PERIPLASMIC PROTEASE, DEGP
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DOI：
10.1101/gad.9.4.387
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发表时间：
1995-02-15
影响因子：
10.5
通讯作者：
SILHAVY, TJ
中科院分区：
文献类型：
--
作者：
DANESE, PN;SNYDER, WB;SILHAVY, TJ
DegP是大肠杆菌中热休克诱导的周质蛋白酶。与细胞质热休克蛋白不同，DegP不受由sigma协调的经典热休克调节子的转录调节（32）。相反，degP基因受交替的热休克sigma因子sigma（E）的转录调节。以前的研究已经证明了一个信号转导途径，监测外膜蛋白在细菌包膜的量，并调节degP水平，响应于此胞外参数。为了分析degP的转录调控，我们研究了改变degP-lacZ操纵子融合转录的突变。cpxA中的功能获得性突变，其指定双组分传感器蛋白，刺激从degP转录。cpxA或编码其同源反应调节因子cpxR的基因中的定义的无效突变降低了degP的转录。这些无效突变还阻止响应于指定包膜脂蛋白的基因的过表达的degP的转录诱导。Cpx介导的degP转录部分依赖于E sigma（E）的活性，表明Cpx途径与E sigma（E）以及可能的其他RNA聚合酶协同作用以驱动degP的转录。
DegP is a heat-shock inducible periplasmic protease in Escherichia coli. Unlike the cytoplasmic heat shock proteins, DegP is not transcriptionally regulated by the classical heat shock regulon coordinated by sigma(32) Rather, the degP gene is transcriptionally regulated by an alternate heat shock sigma factor, sigma(E). Previous studies have demonstrated a signal transduction pathway that monitors the amount of outer-membrane proteins in the bacterial envelope and modulates degP levels in response to this extracytoplasmic parameter. To analyze the transcriptional regulation of degP, we examined mutations that altered transcription of a degP-lacZ operon fusion. Gain-of-function mutations in cpxA, which specifies a two-component sensor protein, stimulate transcription from degP. Defined null mutations in cpxA or the gene encoding its cognate response regulator, cpxR, decrease transcription from degP. These null mutations also prevent transcriptional induction of degP in response to overexpression of a gene specifying an envelope lipoprotein. Cpx-mediated transcription of degP is partially dependent on the activity of E sigma(E), suggesting that the Cpx pathway functions in concert with E sigma(E) and perhaps other RNA polymerases to drive transcription of degP.