Roob Edward, Trendel Nicola, Rein Ten Wolde Pieter, Mugler Andrew
Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana.
Systems Biology Doctoral Training Centre, University of Oxford, Oxford, United Kingdom; FOM Institute AMOLF, Amsterdam, the Netherlands.
Biophys J. 2016 Apr 12;110(7):1661-1669. doi: 10.1016/j.bpj.2016.02.031.
Many membrane-bound molecules in cells form small clusters. It has been hypothesized that these clusters convert an analog extracellular signal into a digital intracellular signal and that this conversion increases signaling fidelity. However, the mechanism by which clusters digitize a signal and the subsequent effects on fidelity remain poorly understood. Here we demonstrate using a stochastic model of cooperative cluster formation that sufficient cooperation leads to digital signaling. We show that despite reducing the number of output states, which decreases fidelity, digitization also reduces noise in the system, which increases fidelity. The tradeoff between these effects leads to an optimal cluster size that agrees with experimental measurements.
细胞中的许多膜结合分子会形成小簇。据推测，这些簇将模拟的细胞外信号转化为数字的细胞内信号，并且这种转化会提高信号保真度。然而，簇将信号数字化的机制以及随后对保真度的影响仍知之甚少。在这里，我们使用协同簇形成的随机模型证明，足够的协同作用会导致数字信号传导。我们表明，尽管减少了输出状态的数量（这会降低保真度），但数字化也会降低系统中的噪声（这会提高保真度）。这些效应之间的权衡导致了一个与实验测量结果相符的最佳簇大小。
