大肠杆菌中孔蛋白基因的渗透调节表达：EnvZ-OmpR磷酸转移信号转导中信号滴定的证据。
Osmoregulatory expression of the porin genes in Escherichia coli: evidence for signal titration in the signal transduction through EnvZ-OmpR phosphotransfer.
作者信息
Nakashima K, Kanamaru K, Aiba H, Mizuno T
机构信息
Laboratory of Microbiology, School of Agriculture, Nagoya University, Japan.
出版信息
FEMS Microbiol Lett. 1991 Jul 15;66(1):43-7. doi: 10.1016/0378-1097(91)90418-a.
The OmpR protein of Escherichia coli is a positive regulator specific for the ompF and ompC genes. The function of OmpR is modulated through phosphotransfer signaling mediated by the kinase, EnvZ. We previously demonstrated that OmpR contains two functional domains, which are physically separable; one is responsible for the interaction with EnvZ, whereas the other participates in interactions with cognate promoter DNAs. In this study, these domains of OmpR were overproduced in wild-type cells harboring the endogenous intact ompR gene on their chromosome. It was found that when the N-terminal domain of OmpR, which contains the phosphorylation site, was overproduced, expression of the ompF and ompC genes was markedly inhibited, irrespective of the osmolarity of the growth medium. Based on our current model for the molecular mechanism underlying signal transduction through Envz-OmpR phosphotransfer (T. Mizuno and S. Mizushima, Mol. Microbiol. 4, (1990), 1077-1082), we provide evidence that this phenomenon is best interpreted by the concept of 'signal titration' in the phosphotransfer signaling pathway.
大肠杆菌的OmpR蛋白是一种对ompF和ompC基因具有特异性的正调控因子。OmpR的功能通过由激酶EnvZ介导的磷酸转移信号传导来调节。我们先前证明，OmpR包含两个功能结构域，它们在物理上是可分离的；一个负责与EnvZ相互作用，而另一个参与与同源启动子DNA的相互作用。在本研究中，OmpR的这些结构域在其染色体上携带内源性完整ompR基因的野生型细胞中过量表达。结果发现，当含有磷酸化位点的OmpR的N端结构域过量表达时，无论生长培养基的渗透压如何，ompF和ompC基因的表达均受到明显抑制。基于我们目前关于通过Envz - OmpR磷酸转移进行信号转导的分子机制模型（T. Mizuno和S. Mizushima，《分子微生物学》4，（1990），1077 - 1082），我们提供证据表明，这种现象最好通过磷酸转移信号通路中的“信号滴定”概念来解释。
Zotero 插件