Study on the Vibro flagellar motor as the mechanosensor

某些海洋弧菌物种在海水中游动，由极鞭毛推动，并使用许多侧鞭毛在表面上游动。极性和侧鞭毛马达分别由钠和质子动力提供动力。侧鞭毛产生于高粘度的介质中，并且相关的粘度传感器是极鞭毛。细胞可以监测鞭毛马达的旋转速率或施加在鞭毛上的机械力。为了测试这些可能性，我们研究了阿米洛利及其衍生物，抑制旋转的dodium驱动的电机，侧鞭毛基因（laf）在副溶血性弧菌的表达的影响。非那米，阿米洛利类似物，抑制游泳微摩尔浓度，诱导laf转录介质中没有粘性剂在剂量依赖性的方式。在不同浓度的非那灭存在下，平均游泳速度和laf诱导之间的关系与改变粘度时观察到的非常相似。这些结果表明，海洋弧菌的感官降低旋转速率（或钠流入通过）的极性鞭毛电机作为触发器的laf诱导。

Certain marine Vibrio species swim in seawater propelled by a polar flagellum and swarm over surfaces using numerous lateral flagella. The polar and the lateral flagellar motors are powered by sodium-and proton-motive forces, respectively. The lateral flagella are produced in media of high viscosity, and the relevant viscosity sensor is the polar flagellum. The cell might monitor either the rotation rate of the flagellar motor or mechanical force applied against the flagellum. To test these possibilities, we examined the effects of amiloride and its derivatives, which inhibit the rotation of the dodium-driven motor, on lateral flagella gene (laf) expression in Vibrio parahaemolyticus. Phenamil, an amiloride analogue that inhibits swimming at micromolar concentrations, induced laf transcription in media devoid of viscous agents in a dose-dependent manner. The relationship between the average swimming speed and laf induction in the presence of various concentrations of phenamil was very similar to that observed when viscosity was changed. These results indicate that marine Vibrio senses decrease in the rotation rate of (or the sodium influx through) the polar flagellar motor as a trigger for laf induction.