论文标题
受体协同对细菌趋化性甲基化动力学的影响，弱梯度弱梯度
Effect of receptor cooperativity on methylation dynamics in bacterial chemotaxis with weak and strong gradient
论文作者
论文摘要
我们研究化学感受器的甲基化动力学作为{\ sl e.coli}细胞在空间变化的化学吸引环境中移动。我们认为具有强和弱的空间梯度的吸引剂浓度。在细胞沿梯度的上坡和下坡运动期间，我们测量受体簇平均甲基化水平的时间变化。我们的数值模拟表明，甲基化动力学敏感地取决于受体簇的大小以及梯度的强度。在运行开始后的短时间内，甲基化动力学主要由通常与高受体活性相关的短期控制。这会在短时间内脱甲基化。但是对于中级或大型时期，长期发挥作用，取决于受体协同或梯度强度，在这个时代，甲基化的定性变化可能完全不同。对于较弱的梯度，对于上坡和下坡的运行，在初始脱甲基化之后，我们发现甲基化水平随着所有群集大小而稳定增加。在上坡运行期间，强大的梯度也观察到了类似的定性行为。然而，下坡的甲基化动力学在强梯度中运行，表明对受体簇尺寸的高度非平凡依赖性。我们解释了这一行为是由于信号网络的传感和适应模块之间的相互作用的结果。
We study methylation dynamics of the chemoreceptors as an {\sl E.coli} cell moves around in a spatially varying chemo-attractant environment. We consider attractant concentration with strong and weak spatial gradient. During the uphill and downhill motion of the cell along the gradient, we measure the temporal variation of average methylation level of the receptor clusters. Our numerical simulations show that the methylation dynamics depends sensitively on the size of the receptor clusters and also on the strength of the gradient. At short times after the beginning of a run, the methylation dynamics is mainly controlled by short runs which are generally associated with high receptor activity. This results in demethylation at short times. But for intermediate or large times, long runs play an important role and depending on receptor cooperativity or gradient strength, the qualitative variation of methylation can be completely different in this time regime. For weak gradient, both for uphill and downhill runs, after the initial demethylation, we find methylation level increases steadily with time for all cluster sizes. Similar qualitative behavior is observed for strong gradient during uphill runs as well. However, the methylation dynamics for downhill runs in strong gradient show highly non-trivial dependence on the receptor cluster size. We explain this behavior as a result of interplay between the sensing and adaptation modules of the signaling network.
