Interaction of sugar transporters and signalling proteins in E. coli chemotaxis

细胞信号和运输网络之间的相互作用协调了对环境变化的反应，因此对微生物具有特别重要的意义。在这里，我们建议调查之间的相互作用感知和吸收的营养物质的例子糖趋向性在大肠杆菌。虽然大肠杆菌趋化作用中的信号转导途径是细胞信号处理定量分析的最受欢迎的模型系统之一，但人们对趋化作用中对氨基酸的信号传递不依赖于运输的分支是很清楚的。研究较少的是糖的信号传递，这与两大类转运蛋白ABC和PTS转运蛋白的摄取有关。基于我们最近对ABC转运相关糖信号的定量描述，我们将在这里研究由PTS输入的各种糖所引起的趋化信号中研究最少的分支。为了阐明这种类型的信号转导的分子机制，我们将使用基于FRET的细胞内途径活性分析来定量分析细胞对PTS糖的反应。此外，我们将结合FRET和生物化学来表征参与PTS介导的趋向性的转运蛋白和趋化蛋白之间的调控相互作用。

Interactions among cellular signalling and transport networks coordinate responses to changes in the environment, and are thus of outstanding importance for microbial organisms. Here we propose to investigate the interplay between sensing and uptake of nutrients on an example of sugar taxis in Escherichia coli. Although the signal transduction pathway in E. coli chemotaxis is one of the favourite model systems for quantitative analyses of cellular signal processing, only the transport-independent branch of the chemotaxis signalling towards amino acid is well understood. Much less investigated is signalling by sugars, which is coupled to uptake by the two major classes of transporters, the ABC and the PTS transporters. Building upon our recent quantitative characterization of the ABC-transport related sugar signalling, we will study here the least-studied branch of the chemotaxis signalling, by a variety of PTS-imported sugars. To elucidate the molecular mechanisms underlying this type of signalling, we will quantitatively analyze cellular responses to PTS sugars using the intracellular assay of the pathway activity based on FRET. Moreover, we will combine FRET and biochemistry to characterize the regulatory interactions among transporter and chemotaxis proteins that are involved in the PTS-mediated taxis.