Energy and information transduction of bacteria flagellar motor of chimeric cell

大肠杆菌细胞将化学感受器感受到的细胞外刺激转换为细胞内信号分子的状态，其调节鞭毛马达的旋转方向从逆时针（CCW）到顺时针（CW）的切换。在这里，我们对鞭毛马达旋转进行了高速成像，并表明细胞上两个不同马达的切换是由细胞内信号蛋白磷酸化CheY（CheY-P）协调控制的。这种转换是高度协调的，电机之间的亚秒级延迟与每个电机与化学感受器贴片的距离相关，化学感受器贴片位于细胞极点。协调开关被组成型活性CheY蛋白的表达所扰乱，该蛋白模仿CW旋转刺激功能。此外，协调开关所需的CheZ，这是一种磷酸酶的CheY-P。我们的研究结果表明，一个短暂的增加和减少的信号蛋白的浓度从化学感受器补丁，这可能是一个波浪状的变化，在第二，触发和调节鞭毛电机的协调开关。我们首先测量了在一个单一的细菌细胞内的信号传播的同时测量多个鞭毛马达的旋转。

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.