TrkH钾离子通道介导的电信号调控大肠杆菌生物被膜形成的机制研究

Bacteria in biofilms have an increased tolerance to antibiotics and are difficult to be eradicated. Clarifying the ways and the regulation mechanisms of cell-to-cell communication in bacterial communities will be an important prerequisite for controlling and taking advantage of biofilms. The electrical signals mediated by potassium channels are important ways for the communication in human, animal and plant cells. However, the roles and mechanisms of potassium channels in the communication of bacteria are not clear. In our previous study, the TrkH potassium channel was found to affect the biofilm forming capability of Escherichia coli. Thus, we proposed that the TrkH potassium channel is related to signal communication between bacteria. In this project, the roles and mechanisms of the electrical signals mediated by TrkH potassium channel in the cell-to-cell communications of Escherichia coli biofilms will be investigated. The genome editing techniques, such as CRISPR/Cas9 will be employed to edit DNA sequences which code the structural proteins of TrkH potassium channel, and then the influences of these molecular modifications on the biofilm-forming ability and the morphological structures of Escherichia coli biofilms will be studied. Furthermore, the influences and regulation mechanisms of electrical signals mediated by TrkH potassium channels on the communication of bacteria in biofilms and the communication between biofilm and floating bacteria will be studied. Finally, the mechanisms of TrkH potassium channel in regulating the formation of biofilm will be illuminated. The scientific hypothesis proposed in this research that bacteria can communicate by the electrical signal mediated by TrkH potassium channel, it is expected to provide new insights into the understanding of the ways and mechanisms for bacteria communication, and provide new ideas and new approaches for effective control, utilization of biofilm and combating bacterial resistance.

生物被膜内细菌耐药性强，难以清除，明确细菌间的通讯机制是有效控制和利用生物被膜的重要前提。目前对细菌通讯方式的认识非常有限，主要集中于群感现象。钾离子通道介导的电信号是人类、动植物细胞信号传导的重要方式，但其在细菌信号交流中的作用及机制尚不清楚。申请人前期研究发现，TrkH钾离子通道影响大肠杆菌生物被膜的形成能力，推测其与细菌间信号传导有关。本项目以大肠杆菌为研究对象，利用CRISPR/Cas9等基因编辑技术，对TrkH钾离子通道结构蛋白的基因序列进行编辑，研究对生物被膜形成能力和形态结构的影响；解析TrkH钾离子通道介导的电信号在生物被膜细菌间、生物被膜与游离细菌间信号交流的作用与机理，进而阐明TrkH钾离子通道调控生物被膜的机制。本项目提出的细菌可通过TrkH钾离子通道进行电信号交流的设想，有望从新的方向揭开细菌间的通讯机制，为有效控制、利用生物被膜及解决细菌耐药性问题提供新的思路。

生物被膜内细菌耐药性强，难以清除，明确细菌间的通讯机制是有效控制和利用生物被膜的重要前提。钾离子通道介导的电信号是人类、动植物细胞信号传导的重要方式，但其在细菌信号传导中的作用及机制尚不清楚。本项目提出细菌可通过离子通道进行交流的设想，探究TrkH钾离子通道对大肠杆菌生物被膜形成的影响及作用机制。利用CRISPR/Cas9等基因编辑技术，成功构建了敲除TrkH钾离子通道结构蛋白TrkA 或TrkH 的大肠杆菌重组菌株△TrkA或△TrkH，研究了TrkH钾离子通道对生物被膜形成能力和形态结构的影响，结果表明，与大肠杆菌原始菌株相比，△TrkA或△TrkH生物被膜形成能力减弱，形成的生物被膜物理性质发生变化，不仅结构较为松散，而且疏水性增强，证实TrkH钾离子通道影响生物被膜的形成。此外，项目还解析了表面静电作用对生物被膜的影响及机制。本项目的研究，有望拓展对细菌间通讯方式和调控机制的认识，为有效控制和利用生物被膜、解决细菌耐药性问题及新型抗菌材料的研发提供新的思路和方法。