Motor processivity and speed determine structure and dynamics of microtubule-motor assemblies.
Motor processivity and speed determine structure and dynamics of microtubule-motor assemblies.
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DOI：
10.7554/elife.79402
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发表时间：
2023-02-08
期刊：
影响因子：
7.7
通讯作者：
Phillips R
中科院分区：
文献类型：
--
作者：
Banks RA;Galstyan V;Lee HJ;Hirokawa S;Ierokomos A;Ross TD;Bryant Z;Thomson M;Phillips R
活性物质系统可以产生高度有序的结构，通过消耗单个成分的能量来避免平衡。表征活性剂的微观参数如何转化为观察到的组装的介观性质仍然是一个悬而未决的问题。这些活性系统在生物物质中普遍存在；例如，在细胞中，通过许多沿着微管行走的运动蛋白的协调活动，细胞骨架被组织成诸如有丝分裂纺锤体之类的结构。在这里，我们研究微观电机-微管相互作用如何影响重构电机-微管系统中形成的相干结构。这个问题具有更深层次的进化意义，因为我们怀疑运动和微管类型对最终结构的形状和大小有贡献。我们从实验和理论上探索关键参数，使用各种不同速度、加工速度和方向的电机。我们证明了aster的尺寸取决于用于创建aster的电机，并开发了稳态aster中电机和微管分布的模型，该模型取决于与电机速度和加工能力相关的参数。在准一维收缩实验中，我们进一步证明了网络收缩速率与单电机速度呈线性关系。总而言之，这项理论和实验工作有助于阐明微观电机特性如何转化为更大规模的集体电机微管组件。
Active matter systems can generate highly ordered structures, avoiding equilibrium through the consumption of energy by individual constituents. How the microscopic parameters that characterize the active agents are translated to the observed mesoscopic properties of the assembly has remained an open question. These active systems are prevalent in living matter; for example, in cells, the cytoskeleton is organized into structures such as the mitotic spindle through the coordinated activity of many motor proteins walking along microtubules. Here, we investigate how the microscopic motor-microtubule interactions affect the coherent structures formed in a reconstituted motor-microtubule system. This question is of deeper evolutionary significance as we suspect motor and microtubule type contribute to the shape and size of resulting structures. We explore key parameters experimentally and theoretically, using a variety of motors with different speeds, processivities, and directionalities. We demonstrate that aster size depends on the motor used to create the aster, and develop a model for the distribution of motors and microtubules in steady-state asters that depends on parameters related to motor speed and processivity. Further, we show that network contraction rates scale linearly with the single-motor speed in quasi-one-dimensional contraction experiments. In all, this theoretical and experimental work helps elucidate how microscopic motor properties are translated to the much larger scale of collective motor-microtubule assemblies.