Involvement of EnvZ-OmpR two-component system in virulence control of Escherichia coli in Drosophila melanogaster.
Involvement of EnvZ-OmpR two-component system in virulence control of Escherichia coli in Drosophila melanogaster.
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DOI：
10.1016/j.bbrc.2013.07.062
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发表时间：
2013-08
影响因子：
3.1
通讯作者：
Pattraporn Pukklay;Y. Nakanishi;M. Nitta;Kaneyoshi Yamamoto;A. Ishihama;A. Shiratsuchi
中科院分区：
文献类型：
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作者：
Pattraporn Pukklay;Y. Nakanishi;M. Nitta;Kaneyoshi Yamamoto;A. Ishihama;A. Shiratsuchi
细菌通过改变基因表达模式来适应环境变化，这是借助于称为双组分调节系统（TCS）的信号转导机制，该系统由两种蛋白质组分组成，即传感激酶和反应调节剂。我们研究了TCS在细菌适应宿主环境中的作用，使用遗传上易处理的生物，大肠杆菌作为病原体，果蝇作为宿主。为了确定果蝇TCS编码基因转录启动子的强度，用一系列E.大肠杆菌表达GFP的启动子分别编码大肠杆菌的27种传感激酶和32种反应调节因子。coliTCS，然后测量荧光强度。我们进一步分析了由具有更强启动子的基因编码的TCS中的EnvZ-OmpR。一个木乃伊。缺失EnvZ-OmpR的大肠杆菌菌株对果蝇存活的致病力高于亲本菌株，而EnvZandompR在突变菌株中的强制表达降低了其致病力。EnvZ-OmpR的缺失对E.大肠杆菌培养基以及可形成菌落的大肠杆菌水平。大肠杆菌苍蝇。增加E。在Imd介导的体液应答缺陷的果蝇中观察到EnvZ-OmpR缺失的大肠杆菌毒力，并且突变体和亲本菌株在体外同样被血细胞吞噬。这些结果表明，EnvZ-OmpR减轻了E.大肠杆菌对果蝇的作用是一种不伴随细菌负荷变化的机制。这种行为E。大肠杆菌最有可能是一种细菌策略，以实现持续感染。
Bacteria adapt to environmental changes by altering gene expression patterns with the aid of signal transduction machinery called the two-component regulatory system (TCS), which consists of two protein components, a sensor kinase and response regulator. We examined the role of the TCS in bacterial adaptation to host environments using genetically tractable organisms,Escherichia colias a pathogen andDrosophila melanogasteras a host. To determine the strength of the transcription promoters of TCS-encoding genes inDrosophila, adult flies were infected with a series ofE. colistrains that expressed GFP driven by the promoters of genes coding for 27 sensor kinases and 32 response regulators ofE. coliTCS followed by the measurement of fluorescence intensities. We further analyzed EnvZ–OmpR among the TCS encoded by genes having stronger promoters. A mutantE. colistrain lacking EnvZ–OmpR had a higher pathogenic effect on fly survival than that of the parental strain, and the forced expression ofenvZandompRin the mutant strain lowered its pathogenicity. The lack of EnvZ–OmpR did not affect the growth ofE. coliin a culture medium as well as the level of colony-formableE. coliin flies. An increase inE. colivirulence with the loss of EnvZ–OmpR was observed in flies defective in an Imd-mediated humoral response, and both the mutant and parental strains were equally engulfed by hemocytesin vitro. These results suggest that EnvZ–OmpR mitigated the virulence ofE. coliinDrosophilaby a mechanism not accompanied by a change of bacterial burden. This behavior ofE. coliis most likely a bacterial strategy to achieve persistent infection.