Helmholtz-University Group Molecular Epidemiology, German Cancer Research Center, Im Neuenheimer Feld 581, D-69120 Heidelberg, Germany.
The Barbara Ann Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI 48201, USA.
Microbiology (Reading). 2010 May;156(Pt 5):1505-1516. doi: 10.1099/mic.0.032847-0. Epub 2010 Jan 21.
In addition to the known response regulator ErbR (former AgmR) and the two-component regulatory system EraSR (former ExaDE), three additional regulatory proteins have been identified as being involved in controlling transcription of the aerobic ethanol oxidation system in Pseudomonas aeruginosa. Two putative sensor kinases, ErcS and ErcS', and a response regulator, ErdR, were found, all of which show significant similarity to the two-component flhSR system that controls methanol and formaldehyde metabolism in Paracoccus denitrificans. All three identified response regulators, EraR (formerly ExaE), ErbR (formerly AgmR) and ErdR, are members of the luxR family. The three sensor kinases EraS (formerly ExaD), ErcS and ErcS' do not contain a membrane domain. Apparently, they are localized in the cytoplasm and recognize cytoplasmic signals. Inactivation of gene ercS caused an extended lag phase on ethanol. Inactivation of both genes, ercS and ercS', resulted in no growth at all on ethanol, as did inactivation of erdR. Of the three sensor kinases and three response regulators identified thus far, only the EraSR (formerly ExaDE) system forms a corresponding kinase/regulator pair. Using reporter gene constructs of all identified regulatory genes in different mutants allowed the hierarchy of a hypothetical complex regulatory network to be established. Probably, two additional sensor kinases and two additional response regulators, which are hidden among the numerous regulatory genes annotated in the genome of P. aeruginosa, remain to be identified.
除了已知的应答调节子 ErbR（前称 AgmR）和双组分调节系统 EraSR（前称 ExaDE）之外，还鉴定出另外三个调节蛋白参与控制铜绿假单胞菌有氧乙醇氧化系统的转录。发现了两个假定的传感器激酶 ErcS 和 ErcS'，以及一个应答调节子 ErdR，它们都与控制甲醇和甲醛代谢的 Paracoccus denitrificans 中的双组分 flhSR 系统具有显著的相似性。鉴定出的三个应答调节子 EraR（前称 ExaE）、ErbR（前称 AgmR）和 ErdR 都是 luxR 家族的成员。三个传感器激酶 EraS（前称 ExaD）、ErcS 和 ErcS'不包含膜结构域。显然，它们定位于细胞质中并识别细胞质信号。基因 ercS 的失活导致在乙醇上的延长的迟滞期。基因 ercS 和 ercS'的同时失活导致在乙醇上完全不能生长， ErdR 的失活也是如此。在迄今为止鉴定出的三个传感器激酶和三个应答调节子中，只有 EraSR（前称 ExaDE）系统形成相应的激酶/调节子对。使用不同突变体中所有鉴定的调节基因的报告基因构建体，建立了一个假设的复杂调节网络的层次结构。可能，在铜绿假单胞菌基因组中注释的众多调节基因中，还有另外两个传感器激酶和另外两个应答调节子有待鉴定。
