The flagellar motor as a sensor

描述(申请人提供)：鞭毛马达作为传感器细菌利用螺旋鞭毛的旋转来推动自己通过散装液体(游泳)或通过 固体表面上的一层薄薄的液体(成群的)。化学传感通路通常将环境信息传递给双向旋转马达，调节其顺向/逆时针偏向，以优化细菌向有利地点的迁移。这些途径是众所周知的。在大肠杆菌和其他细菌中，马达本身也是一个感官细胞器，使细菌能够适应化学信号，直接对增加的c-di-GMP做出反应，并机械地感觉到固体表面。这些途径，尤其是机械传感，并不为人所知。鉴于最近的证据表明，电机在化学传感和机械传感过程中都会重构其定子和转子部件，我们提出了一个新的可测试的电机作为机械传感器的模型。该模型将转子-定子界面识别为电机的感觉中枢。我们考虑了有限数量的结构组件，它们可以接收和转换来自这个中枢的感觉信号。它们是：MOTA/B、FliG、Flim、FliL、YcgR和H-NS。这项建议的前两个目的是研究在电机对两个内部信号-Chey~P和c-di-GMP产生不同反应的情况下，这些组件的子集的重塑。第三个目标得益于这一知识，以监测这些组件响应机械信号的重塑。从这些研究中得出的见解有望最终追踪到运动的输入信号(S)，以输出促进运动或静止(生物膜)的反应，这两者在细菌感染、表面定植、发病机制和持久性方面都发挥着关键作用。

DESCRIPTION (provided by applicant): The Flagellar Motor as a Sensor Bacteria use rotation of helical flagella to propel themselves either through bulk liquid (swimming), or through a thin film of liquid on a solid surface (swarming). Chemosensory pathways normally communicate environmental information to the bidirectional rotary motor, modulating its CW/CCW bias to optimize bacterial migration towards favorable locales. These pathways are well-understood. In E. coli and other bacteria, the motor is also itself a sensory organelle, allowing bacteria to adapt to chemical signals, respond directly to increased c-di- GMP, and mechanically 'sense' a solid surface. These pathways, particularly mechanosensing, are not understood. In light of recent evidence showing that the motor restructures its stator and rotor components during both chemosensing and mechanosensing, we propose a new testable model for how the motor acts as a mechanosensor. The model identifies the rotor-stator interface as the sensory hub of the motor. We consider a finite number of structural components that could receive and transduce sensory signals from this hub. These are: MotA/B, FliG, FliM, FliL, YcgR and H-NS. The first two aims of this proposal investigate remodeling of a subset of these components under situations where the motor elicits a distinct response to two internal signals - CheY~P and c-di-GMP. The third aim benefits from this knowledge to monitor remodeling of these components in response to mechano-signals. The insights derived from these studies are expected to eventually trace the input signal(s) at the motor to output responses that promote either motility or sessility (biofilms), both of which play critical roles i bacterial infection, surface colonization, pathogenesis, and persistence.