Visualization of functional rotor proteins of the bacterial flagellar motor in the cell membrane
Visualization of functional rotor proteins of the bacterial flagellar motor in the cell membrane
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DOI：
10.1016/j.jmb.2007.01.015
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发表时间：
2007-03-30
影响因子：
5.6
通讯作者：
Homma, Michio
中科院分区：
文献类型：
--
作者：
Fukuoka, Hajime;Sowa, Yoshiyuki;Homma, Michio
细菌鞭毛马达是由特定离子穿过细胞膜的电化学电势驱动的旋转马达。转子蛋白FliG和定子蛋白MotA之间的直接相互作用被认为产生旋转扭矩。在这里，我们使用全内反射荧光显微镜观察绿色荧光蛋白（GFP）融合的FliG在大肠杆菌细胞中的定位。我们鉴定了三种类型的荧光点状信号：非移动的点、表现出简单扩散的移动的点和表现出受限扩散的移动的点。当GFP-FliG在Delta fliG背景中表达时，大多数细胞不是移动的。然而，当细胞被拴系到玻璃侧时，通常观察到旋转细胞，并且在拴系细胞的旋转中心处总是观察到单个荧光点。这些荧光点可能是功能性GFP-FliG已被并入鞭毛马达的位置。我们的研究结果表明，鞭毛基体在细胞质膜中扩散，直到轴向结构和/或其他结构组装。(c)2007爱思唯尔有限公司保留所有权利。
The bacterial flagellar motor is a rotary motor driven by the electrochemical potentials of specific ions across the cell membrane. Direct interactions between the rotor protein FliG and the stator protein MotA are thought to generate the rotational torque. Here, we used total internal reflection fluorescent microscopy to observe the localization of green fluorescent protein (GFP)-fused FliG in Escherichia coli cells. We identified three types of fluorescent punctate signals: immobile dots, mobile dots that exhibited simple diffusion, and mobile dots that exhibited restricted diffusion. When GFP-FliG was expressed in a Delta fliG background, most of the cells were not mobile. When the cells were tethered to a glass side, however, rotating cells were commonly observed and a single fluorescent dot was always observed at the rotational center of the tethered cell. These fluorescent dots were likely positions at which functional GFP-FliG had been incorporated into a flagellar motor. Our results suggest that flagellar basal bodies diffuse in the cytoplasmic membrane until the axial structure and/or other structures assemble. (c) 2007 Elsevier Ltd. All rights reserved.