Energy and information transduction of bacteria flagellar motor of chimeric cell

大肠杆菌细胞将化学感受器感知的细胞外刺激转换为细胞内信号分子状态，从而调节鞭毛马达的旋转方向从逆时针（CCW）转向顺时针（CW）。在这里，我们对鞭毛马达旋转进行了高速成像，并显示细胞上两个不同马达的开关是由细胞内磷酸化的CheY （CheY- p）信号蛋白协调控制的。开关是高度协调的，马达之间的亚秒延迟与每个马达到化学感受器贴片的距离有关，这是定位在细胞极点。协调开关被组成活性CheY蛋白的表达扰乱，该蛋白模拟了cw旋转刺激功能。同时，协调的切换需要CheZ，这是CheY-P的磷酸酶。我们的研究结果表明，来自化学受体贴片的信号蛋白浓度的短暂增加和减少，可能是在不到一秒的时间内发生的波状变化，触发并调节鞭毛马达的协调开关。我们首先通过同时测量多个鞭毛马达的旋转来测量单个细菌细胞内信号的传播。

An Escherichia coli cell transduces extracellular stimuli sensed by chemoreceptors to the state of an intracellular signal molecule, which regulates switching of the rotational direction of the flagellar motors from counterclockwise (CCW) to clockwise (CW). Here, we performed high-speed imaging of flagellar motor rotation and showed that the switching of two different motors on a cell is controlled coordinately by an intracellular signal protein, phosphorylated CheY (CheY-P). The switching is highly coordinated, with a sub-second delay between motors that is correlated with the distance of each motor from the chemoreceptor patch, which is localized at the cell pole. The coordinated switching was disordered by the expression of constitutively active CheY protein, which mimics the CW-rotation stimulating function. Also, the coordinated switching was required the CheZ, which is a phosphatase for CheY-P. Our results suggest that a transient increase and decrease in the concentration of a signal protein from the chemoreceptor patch, which is probably a wave-like change in under a second, triggers and regulates the coordinated switching of flagellar motors. We firstly measured the propagation of intracellular signaling in a single bacterial cell by applying the simultaneous measurement for the rotation of multiple flagellar motors.