Rubinstein Boris Y, Mogilner Alex
Stowers Institute, Kansas City, Missouri, New York University, New York, New York.
Courant Institute of Mathematical Sciences, New York University, New York, New York; Department of Biology, New York University, New York, New York.
Biophys J. 2017 Aug 22;113(4):937-947. doi: 10.1016/j.bpj.2017.07.003.
Myosin-powered force generation and contraction in nonmuscle cells underlies many cell biological processes and is based on contractility of random actin arrays. This contractility must rely on a microscopic asymmetry, the precise mechanism of which is not completely clear. A number of models of mechanical and structural asymmetries in actomyosin contraction have been posited. Here, we examine a contraction mechanism based on a finite size of myosin clusters and anisotropy of force generation by myosin heads at the ends of the myosin clusters. We use agent-based numerical simulations to demonstrate that if average lengths of actin filaments and myosin clusters are similar, then the proposed microscopic asymmetry leads to effective contraction of random 1D actomyosin arrays. We discuss the model's implication for mechanics of contractile rings and stress fibers.
肌球蛋白驱动的非肌肉细胞中的力产生和收缩是许多细胞生物学过程的基础，并且基于随机肌动蛋白阵列的收缩性。这种收缩性必须依赖于微观不对称性，其精确机制尚不完全清楚。已经提出了许多关于肌动球蛋白收缩中机械和结构不对称性的模型。在这里，我们研究了一种基于肌球蛋白簇有限大小以及肌球蛋白簇末端肌球蛋白头部产生力的各向异性的收缩机制。我们使用基于智能体的数值模拟来证明，如果肌动蛋白丝和肌球蛋白簇的平均长度相似，那么所提出的微观不对称性会导致随机一维肌动球蛋白阵列的有效收缩。我们讨论了该模型对收缩环和应力纤维力学的意义。
