Microbiorogical Adaptation and Signal Transduction

本实验室发现了一个新的双组分系统，即evgS和evgA基因（Gene 140，73 - 77，1994）。利用该系统，我们研究了大肠杆菌适应环境变化和生存的信号转导机制。结果表明，多药耐药基因（emrK、emrY，登录号，D 78168）的表达受EvgA和EvgS的调节（J.Gen.Microbiol，出版中）。同时，四环素耐药菌株出现频率较高。本研究首次揭示了细菌对药物的适应性和突变机制，通过EvgS和EvgA构建的系统是了解适应性突变机制的理想工具。在未来，这是有希望的发展这方面的研究，并显示详细的分子机制。这些结果将有助于建立一种新的抗菌药物筛选方法，并为进化工程开辟一条道路。

A new two component system, evgS and evgA genes were identified (Gene 140,73-77,1994) in this esearch, Using this system, we have been studying the signal transduction mechanism how E.coli can adapt to the environmental changes and survival. At the results, multidrug-resistance genes (emrK,emrY,accession #, D78168) expression were shown to be regulated by EvgA and EvgS (J.Gen.Microbiol, in press).When E.coli was cultured in the presence of the drugs, the emrK and emrY genes expression were induced by tetracycline. At the same time, tetracycline-resistant strains appeared at the high frequency. These results how bacteria adapt to drug and be mutated was shown at first in this research.This system via EvgS and EvgA is ideal to understand the mechanism of the adaptated mutation. In the future, it is hopeful to develop this research and show the molecular mechanism in detail. These results should be useful to make a new screening method of antimicrobial agents as well as to lead a way to the evolutional engineering.