Active contractility in actomyosin networks
Active contractility in actomyosin networks
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DOI：
10.1073/pnas.1204205109
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发表时间：
2012-04-24
影响因子：
11.1
通讯作者：
Wolynes, Peter G.
中科院分区：
文献类型：
--
作者：
Wang, Shenshen;Wolynes, Peter G.
收缩力是许多发育过程中必不可少的，包括细胞形状变化和组织变形。最近对重构的肌动球蛋白网络（收缩机制的主要组成部分）的实验表明，主动收缩性发生在阈值运动浓度以上和交联浓度的窗口内。我们提出了一个微观动力学模型，其中包括两个基本方面的肌动球蛋白自组织：不对称的负载响应的个别肌动蛋白丝和相关的电机驱动的事件模仿肌球蛋白诱导的丝滑动。利用计算机模拟，我们研究了马达的浓度和敏感性如何影响它们的集体行为，并与网络连接相互作用以调节宏观收缩性。我们的模型捕捉到的收缩结构的形成和动力学，并同意所观察到的依赖性的积极收缩微观参数，包括收缩性发作。力渗透结构中抗载荷电机的协同作用通过主动粗化过程将局部收缩/屈曲事件整合到全局收缩状态，这与易感电机的不相关反冲驱动的流动转变相反。
Contractile forces are essential for many developmental processes involving cell shape change and tissue deformation. Recent experiments on reconstituted actomyosin networks, the major component of the contractile machinery, have shown that active contractility occurs above a threshold motor concentration and within a window of cross-link concentration. We present a microscopic dynamic model that incorporates two essential aspects of actomyosin self-organization: the asymmetric load response of individual actin filaments and the correlated motor-driven events mimicking myosin-induced filament sliding. Using computer simulations, we examine how the concentration and susceptibility of motors contribute to their collective behavior and interplay with the network connectivity to regulate macroscopic contractility. Our model is shown to capture the formation and dynamics of contractile structures and agree with the observed dependence of active contractility on microscopic parameters, including the contractility onset. Cooperative action of load-resisting motors in a force-percolating structure integrates local contraction/buckling events into a global contractile state via an active coarsening process, in contrast to the flow transition driven by uncorrelated kicks of susceptible motors.