Limited processivity of single motors improves overall transport flux of self-assembled motor-cargo complexes
Limited processivity of single motors improves overall transport flux of self-assembled motor-cargo complexes
复制标题
单个电机的有限加工能力提高了自组装汽车货运综合体的整体运输通量
DOI：
10.1103/physreve.100.022408
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发表时间：
2019
影响因子：
2.4
通讯作者：
Newby, Jay M.
中科院分区：
文献类型：
--
作者：
Patel, Keshav B.;Mao, Shengtan;Forest, M. Gregory;Lai, Samuel K.;Newby, Jay M.
单个驱动蛋白分子马达在解离前可沿微管（MT）连续沿着移动几微米。然而，发生运输的细胞长度尺度是几百微米或更大。为什么看似不可靠的发动机被用来运输细胞货物仍然知之甚少。我们提出了一个理论，如何低的持续性，一轮定向运动的平均长度，可以增强细胞运输时，电机和货物必须首先扩散自组装成复合物。我们采用随机建模，以确定对整体货物运输流量的持续合成能力的影响。我们发现，在广泛的生理相关条件下，拥有“无限”的持续合成能力并不能最大限度地提高沿着MT的通量。相反，我们发现降低持续合成能力，即，马达与MT的结合较弱，可以提高运输通量。这些结果揭示了持续合成能力和运输效率之间的关系，并为低运动持续合成能力的生理益处提供了理论。
Single kinesin molecular motors can processively move along a microtubule (MT) a few micrometers on average before dissociating. However, cellular length scales over which transport occurs are several hundred microns and more. Why seemingly unreliable motors are used to transport cellular cargo remains poorly understood. We propose a theory for how low processivity, the average length of a single bout of directed motion, can enhance cellular transport when motors and cargos must first diffusively self-assemble into complexes. We employ stochastic modeling to determine the effect of processivity on overall cargo transport flux. We show that, under a wide range of physiologically relevant conditions, possessing “infinite” processivity does not maximize flux along MTs. Rather, we find that lowering processivity, i.e., weaker binding of motors to MTs, can improve transport flux. These results shed light on the relationship between processivity and transport efficiency and offer a theory for the physiological benefits of low motor processivity.