Cargo navigation across 3D microtubule intersections
Cargo navigation across 3D microtubule intersections
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DOI：
10.1073/pnas.1707936115
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发表时间：
2018-01-16
影响因子：
11.1
通讯作者：
Vershinin, Michael D.
中科院分区：
文献类型：
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作者：
Bergman, Jared P.;Bovyn, Matthew J.;Vershinin, Michael D.
真核细胞的微管细胞骨架是一个复杂的三维纤维网络。微管以各种各样的分离距离和角度交叉。先前的体内和体外研究表明，货物运输受到交叉口几何形状的影响。然而，几何复杂性尚未被广泛理解为其本身的调节因素，并且这种调节模式的机制也没有得到很好的理解。我们已经使用我们最近报道的3D微管操作系统在纯化的体外环境中从头构建丝交叉，并使用它们来检测驱动蛋白-1驱动的模型货物导航。我们发现，3D微管网络的几何形状确实显著影响货物路线，特别是有可能通过改变灯丝间距或角度来偏置货物通过或切换。此外，我们在一个模型中捕获了我们的实验结果，该模型考虑了完整的3D几何形状，货物和相关电机的随机运动，以及电机力产生和力依赖行为。我们采用实验和理论分析相结合的方法来建立微管交叉口货物导航的详细机制。
The eukaryotic cell's microtubule cytoskeleton is a complex 3D filament network. Microtubules cross at a wide variety of separation distances and angles. Prior studies in vivo and in vitro suggest that cargo transport is affected by intersection geometry. However, geometric complexity is not yet widely appreciated as a regulatory factor in its own right, and mechanisms that underlie this mode of regulation are not well understood. We have used our recently reported 3D microtubule manipulation system to build filament crossings de novo in a purified in vitro environment and used them to assay kinesin-1-driven model cargo navigation. We found that 3D microtubule network geometry indeed significantly influences cargo routing, and in particular that it is possible to bias a cargo to pass or switch just by changing either filament spacing or angle. Furthermore, we captured our experimental results in a model which accounts for full 3D geometry, stochastic motion of the cargo and associated motors, as well as motor force production and force-dependent behavior. We used a combination of experimental and theoretical analysis to establish the detailed mechanisms underlying cargo navigation at microtubule crossings.