Noise-Induced Increase of Sensitivity in Bacterial Chemotaxis
Noise-Induced Increase of Sensitivity in Bacterial Chemotaxis
复制标题
噪声引起的细菌趋化敏感性增加
DOI：
10.1016/j.bpj.2016.06.013
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发表时间：
2016-07-26
影响因子：
3.4
通讯作者：
Yuan, Junhua
中科院分区：
文献类型：
--
作者：
He, Rui;Zhang, Rongjing;Yuan, Junhua
鞭毛细菌，如大肠杆菌，可以通过趋化性信号转导网络调节鞭毛马达的旋转方向，向有益的环境游去。该网络的噪声，即细胞内信号蛋白CheY-P浓度随时间的随机波动，已在单细胞行为变异性的研究中被发现，并发现在细菌中多个马达的协调和化学梯度中细菌漂移速度的增强中起重要作用。在这里，通过比较野生型大肠杆菌和没有信号噪声的突变体的马达之间的行为差异，我们测量了野生型细胞中这种噪音的大小，发现噪音在鞭毛马达水平上增加了下游细菌趋化网络的敏感性。这为噪声诱导趋化漂移的增强提供了一个简单的机制，我们通过模拟大肠杆菌在不同化学引诱剂浓度的空间剖面上的趋化运动来证实这一点。
Flagellated bacteria, like Escherichia coli, can swim toward beneficial environments by modulating the rotational direction of their flagellar motors through a chemotaxis signal transduction network. The noise of this network, the random fluctuation of the intracellular concentration of the signal protein CheY-P with time, has been identified in studies of single cell behavioral variability, and found to be important in coordination of multiple motors in a bacterium and in enhancement of bacterial drift velocity in chemical gradients. Here, by comparing the behavioral difference between motors of wild-type E. coli and mutants without signal noise, we measured the magnitude of this noise in wild-type cells, and found that the noise increases the sensitivity of the bacterial chemotaxis network downstream at the level of the flagellar motor. This provided a simple mechanism for the noise-induced enhancement of chemotactic drift, which we confirmed by simulating the E. coli chemotactic motion in various spatial profiles of chemo-attractant concentration.