Channing Laboratory, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
Genes Dev. 2011 Jul 15;25(14):1544-55. doi: 10.1101/gad.2061811.
Stochastic processes are thought to mediate localization of membrane-associated chemotaxis signaling clusters in peritrichous bacteria. Here, we identified a new family of ParA-like ATPases (designated ParC [for partitioning chemotaxis]) encoded within chemotaxis operons of many polar-flagellated γ-proteobacteria that actively promote polar localization of chemotaxis proteins. In Vibrio cholerae, a single ParC focus is found at the flagellated old pole in newborn cells, and later bipolar ParC foci develop as the cell matures. The cell cycle-dependent redistribution of ParC occurs by its release from the old pole and subsequent relocalization at the new pole, consistent with a "diffusion and capture" model for ParC dynamics. Chemotaxis proteins encoded in the same cluster as ParC have a similar unipolar-to-bipolar transition; however, they reach the new pole after the arrival of ParC. Cells lacking ParC exhibit aberrantly localized foci of chemotaxis proteins, reduced chemotaxis, and altered motility, which likely accounts for their enhanced colonization of the proximal small intestine in an animal model of cholera. Collectively, our findings indicate that ParC promotes the efficiency of chemotactic signaling processes. In particular, ParC-facilitated development of a functional chemotaxis apparatus at the new pole readies this site for its development into a functional old pole after cell division.
随机过程被认为介导了周质相关趋化信号簇在周毛菌中的定位。在这里，我们鉴定了许多极性鞭毛γ-变形菌的趋化操纵子内编码的新的 ParA 样 ATP 酶家族（命名为 ParC[用于分配趋化作用]），它们积极促进趋化蛋白的极性定位。在霍乱弧菌中，单个 ParC 焦点位于新生细胞的鞭毛旧极，随着细胞成熟，后来双极 ParC 焦点发展。ParC 的细胞周期依赖性重新分布是通过其从旧极释放并随后在新极重新定位来实现的，这与 ParC 动力学的“扩散和捕获”模型一致。与 ParC 编码在同一簇中的趋化蛋白也经历了从单极到双极的转变；然而，它们在 ParC 到达后到达新极。缺乏 ParC 的细胞表现出趋化蛋白的异常定位焦点、趋化作用降低和运动能力改变，这可能解释了它们在霍乱动物模型中增强了对近端小肠的定植。总的来说，我们的发现表明 ParC 促进了趋化信号过程的效率。特别是，ParC 促进了新极功能性趋化作用装置的发展，为细胞分裂后该部位发展成为功能性旧极做好了准备。
