希瓦氏奥内达菌鞭毛组装调控的分子机制研究

Shewanella oneidensis is renowned for its respiratory capacity and thus in recent years receives enormous attentions from both fundamental and applied research fields. The flagellar system is not only essential to bacterial motility but also is implicated in many important physiological processes such as chemotaxis, biofilm formation, respiration on solid electron acceptors. For four years, the flagellar system has been one of our research focuses, aiming at providing great insights into current understanding of the flagellar system and its impacts on the physiology of S. oneidensis in general. This study, which is based on our previous findings and accumulated experimental materials, emphasizes on regulation of the flagellar system, attempting to solve two long-standing puzzles: the control of the number of filament and its location. We anticipate that these sutdy would allow us to understand the mechanism underlying the functional difference between two highly homologous flagellins and through evolutional analysis propose the major function of the flagellar system in this particular microorganism; to determine the position of the FlrBC two-component system in the regulatory hierarchy and to pinpoint those under its direct control; to illustrate the precise processes affected by FlrC that is independent of FlrB and the FlrC partners as well as the interaction between them; to investigate the mechanism by which the flagellar system is confined to the pole of cells. To address these fundamental scientific questions would ensure us as one of the leading research teams in the S. oneidensis and bacterial research society.

希瓦氏奥内达菌呼吸能力出众，在基础和应用领域目前都受到广泛关注。由于细菌的鞭毛与包括运动、趋化、群落形成、固体电子受体呼吸等生命过程直接相关，本实验室近年针对该菌的鞭毛系统展开了深入研究。本申请课题基于实验室已有发现和物质基础，关注鞭毛系统组装的调控，旨在在分子层面理解细菌鞭毛的数目控制和细胞定位。通过研究，期望弄清导致两个序列高度一致但功能差异极大的鞭毛丝亚基的机制，通过进化分析了解鞭毛系统在希瓦氏奥内达菌中的关键作用；确定二元调控系统FlrBC在鞭毛调控层级中的位置和作用，找出被其影响的鞭毛基因；阐明FlrC不依赖于FlrB的具体功能及其信号伙伴蛋白，分析其相互作用方式；探明极性鞭毛的定位机制。这些重要基础科学问题的解答将保证本课题组在希瓦氏奥内达菌研究方面居于世界前列。

希瓦氏菌呼吸能力出众，在基础和应用领域目前都受到广泛关注。由于细菌的鞭毛与包括运动、趋化、群落形成、固体电子受体呼吸等生命过程直接相关，本实验室近年来针对该菌的鞭毛系统展开了深入研究。本课题基于实验室已有发现和物质基础，关注鞭毛系统组装的调控，旨在在分子层面理解细菌鞭毛的数目控制和细胞定位。课题在开展过程中，严格依照研究内容，对提出的科学问题逐层分析解决，取得了丰硕的成果。具体为：通过研究，弄清了导致两个序列高度一致但功能差异极大的鞭毛丝亚基的机制，及各自在希瓦氏奥内达菌中的关键作用；确定了二元调控系统FlrBC 在鞭毛调控层级中的位置和作用，找出被其影响的鞭毛基因；阐明FlrC 不依赖于FlrB 的具体功能及其信号伙伴蛋白，揭示了其相互作用方式；初步探明了极性鞭毛的定位机制。这些重要基础科学问题的解答不但在分子层面上解释了这一大类遍布海洋的细菌的生存策略，保证本课题组在希瓦氏奥内达菌研究方面居于世界前列，而且为该类细菌在生物修复、生物能源、生物新材料等方面的应用提供指导。