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

细胞信号和传输网络之间的相互作用协调了对环境变化的反应，因此对微生物有机体非常重要。本文以大肠杆菌的糖趋向性为例，研究了营养物质的感知和吸收之间的相互作用。虽然大肠杆菌趋化性的信号转导途径是细胞信号处理定量分析中最受欢迎的模型系统之一，但只有氨基酸趋化性信号的转运独立分支被很好地理解。较少研究的是糖的信号，它与两种主要转运体，ABC和PTS转运体的摄取相结合。基于我们最近对abc转运相关糖信号的定量表征，我们将通过各种pts进口糖来研究趋化性信号的研究最少的分支。为了阐明这类信号传导的分子机制，我们将利用基于FRET的通路活性的细胞内测定，定量分析细胞对PTS糖的反应。此外，我们将结合FRET和生物化学来表征转运蛋白和趋化蛋白之间的调节相互作用，这些蛋白参与了pts介导的趋化。

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.