Comprehensive analysis of transcriptional regulatory network in Escherichia coli

点击翻译按钮获取中文摘要

In this project, we tried to analyze the whole function of all two component systems in E coli For this, we isolated 36 two component deletion mutants in which each system is deleted individually. By using the microarray and the SELEX methods, we could identify or suggest the target genes (or regulon) controlled and cis-acting sequences recognized by two component systems. Moreover, we could identify the stress signals that were perceived by two component systems, and we revealed that the stresses could be categorized into metabolic' signals (carbon, nitrogen, and compound related to respiration etc), ion/metal stresses (Fe, Cu, Mg, Zn, K, and P etc.), and the diverse stresses (cell surface stress, oxidation stress, and osmotic stress, etc). We also suggested that there are signaling networks between two component systems.On the other hand, we purified all His kinases and response regulators and carried out every phosphorylation experiment in vitro. As a result, we could identify the non cognate pairs of His kinase and response regulators that could cross talk (trans phosphorylate) each other. It is necessary to reveal the physiological significance of the suggested cross talk in vivo in the future.In an individual analysis, we identified two component systems that regulate stationary specific sigma factor (RpoS). We also identified two component systems that regulate flagella expression.In this project, useful resources such as deletion mutants of all two component systems, expression plasmids of all two component genes, purified proteins, plasmids for two hybrid analysis in E coli etc. were prepared.