Department of Chemistry, University of Chicago, Chicago, IL 60637, USA.
Mol Syst Biol. 2010 Dec 21;6:445. doi: 10.1038/msb.2010.95.
Sensor histidine kinases underlie the regulation of a range of physiological processes in bacterial cells, from chemotaxis to cell division. In the gram-negative bacterium Caulobacter crescentus, the membrane-bound histidine kinase, DivJ, is a polar-localized regulator of cell cycle progression and development. We show that DivJ localizes to the cell pole through a dynamic diffusion and capture mechanism rather than by active localization. Analysis of single C. crescentus cells in microfluidic culture demonstrates that controlled expression of divJ permits facile tuning of both the mean and noise of the cell division period. Simulations of the cell cycle that use a simplified protein interaction network capture previously measured oscillatory protein profiles, and recapitulate the experimental observation that deletion of divJ increases the cell cycle period and noise. We further demonstrate that surface adhesion and swarming motility of C. crescentus in semi-solid media can also be tuned by divJ expression. We propose a model in which pleiotropic control of polar cell development by the DivJ-DivK-PleC signaling pathway underlies divJ-dependent tuning of cell swarming and adhesion behaviors.
传感器组氨酸激酶是细菌细胞中一系列生理过程（从趋化作用到细胞分裂）调节的基础。在革兰氏阴性菌新月柄杆菌中，膜结合组氨酸激酶 DivJ 是细胞周期进程和发育的极性定位调节剂。我们表明，DivJ 通过动态扩散和捕获机制而不是主动定位定位于细胞极。在微流控培养中对单个新月柄杆菌细胞的分析表明，divJ 的受控表达允许轻松调整细胞分裂周期的平均值和噪声。使用简化的蛋白质相互作用网络模拟细胞周期可以捕获之前测量的振荡蛋白谱，并再现实验观察结果，即 divJ 的缺失会增加细胞周期周期和噪声。我们进一步证明，在半固体培养基中，新月柄杆菌的表面粘附和群集运动也可以通过 divJ 的表达进行调节。我们提出了一个模型，其中 DivJ-DivK-PleC 信号通路对极性细胞发育的多效性控制是 divJ 依赖性调节细胞群集和粘附行为的基础。
