Processive kinesins require loose mechanical coupling for efficient collective motility
Processive kinesins require loose mechanical coupling for efficient collective motility
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DOI：
10.1038/embor.2008.169
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发表时间：
2008-11-01
期刊：
影响因子：
7.7
通讯作者：
Surrey, Thomas
中科院分区：
文献类型：
--
作者：
Bieling, Peter;Telley, Ivo A.;Surrey, Thomas
进行性马达蛋白是随机步进器，其执行实际机械步骤的时间仅为它们结合到细丝轨道的时间的一小部分。电动机通常在团队中工作，因此问题出现了，当电动机机械耦合时，步进的随机性是否会导致相互干扰。我们使用生物相容性表面以机械定义明确的方式在受控的表面密度下对驱动蛋白-1马达进行处理。这有助于我们定量研究马达之间的机械耦合如何影响集体微管运输的效率。我们发现，驱动蛋白-1的结构，缺乏大部分的非电机序列时，集体运输微管，根据相互作用的电机的数量减慢对方。对于运动系综观察到的这种负干扰可以通过使用驱动蛋白-1的单个分子的已知物理性质的数学模型来定量地解释。驱动蛋白-1的非马达延伸减少了这种相互干扰，这表明马达之间的松散机械耦合是进行性马达的合奏所需的有效运输。
Processive motor proteins are stochastic steppers that perform actual mechanical steps for only a minor fraction of the time they are bound to the filament track. Motors usually work in teams and therefore the question arises whether the stochasticity of stepping can cause mutual interference when motors are mechanically coupled. We used biocompatible surfaces to immobilize processive kinesin-1 motors at controlled surface densities in a mechanically well-defined way. This helped us to study quantitatively how mechanical coupling between motors affects the efficiency of collective microtubule transport. We found that kinesin-1 constructs that lack most of the non-motor sequence slow each other down when collectively transporting a microtubule, depending on the number of interacting motors. This negative interference observed for a motor ensemble can be explained quantitatively by a mathematical model using the known physical properties of individual molecules of kinesin-1. The non-motor extension of kinesin-1 reduces this mutual interference, indicating that loose mechanical coupling between motors is required for efficient transport by ensembles of processive motors.