Modulation of the mechano-chemical properties of myosin V by drebrin-E
Modulation of the mechano-chemical properties of myosin V by drebrin-E
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DOI：
10.1016/j.bbrc.2010.08.120
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发表时间：
2010-10-01
影响因子：
3.1
通讯作者：
Ishiwata, Shin'ichi
中科院分区：
文献类型：
--
作者：
Kubota, Hiroaki;Ishikawa, Ryoki;Ishiwata, Shin'ichi
各种蛋白质对肌动蛋白丝网络的调节在生长锥动力学中具有重要作用。在这项研究中，我们专注于肌动蛋白-肌球蛋白的相互作用，已被认为是一个重要的球员在神经突起的延伸。我们研究了在体外如何装饰的肌动蛋白丝与侧结合蛋白，drebrin-E，影响细胞内转运肌球蛋白V的运动特性。单个肌球蛋白V分子降落在drebrin-E装饰的肌动蛋白丝上，频率较低，运行距离较短;然而，它们的速度是正常的。此外，在光阱中的肌球蛋白V分子的运动的分析表明，装饰肌动蛋白丝与drebrin-E显着增加肌球蛋白V步进的负载敏感性。这些结果可归因于延迟的附件电机的领先头（ADP.P-i状态）肌动蛋白，诱导的竞争性结合drebrin-E肌动蛋白，而ADP释放率从拖尾头（限速步骤中的ATP酶的肌球蛋白V的循环）不受影响。我们的研究表明，除了调节肌球蛋白V的结合亲和力，drebrin-E还调节能动肌球蛋白V分子中的化学-机械耦合，可能影响生长锥的运动。(c)2010年爱思唯尔公司All rights reserved.
The regulation of actin filament networks by various proteins has essential roles in the growth cone dynamics. In this study we focused on the actin-myosin interaction which has been suggested to be an important player in the neurite extension. We examined in vitro how the decoration of actin filaments with a side-binding protein, drebrin-E, affects the motile properties of an intracellular transporter myosin V. Single myosin V molecules landed on the drebrin-E-decorated actin filaments with a lower frequency and ran over shorter distances; however, their velocities were normal. Furthermore, the analysis of the movement of myosin V molecules in the optical trap revealed that the decoration of actin filaments with drebrin-E markedly increased the load-sensitivity of the myosin V stepping. These results are attributable to the delay in the attachment of the motor's leading head (ADP.P-i state) to actin, induced by the competitive binding of drebrin-E to actin, whereas the rate of ADP release from the trailing head (the rate-limiting step in the ATPase cycle of myosin V) is unaffected. Our study indicates that, in addition to the regulation of binding affinity of myosin V. drebrin-E also modulates the chemo-mechanical coupling in the motile myosin V molecules, presumably affecting the movement of the growth cone. (c) 2010 Elsevier Inc. All rights reserved.