A model for kinesin movement from nanometer-level movements of kinesin and cytoplasmic dynein and force measurements
A model for kinesin movement from nanometer-level movements of kinesin and cytoplasmic dynein and force measurements
复制标题
驱动蛋白运动的模型，来自驱动蛋白和细胞质动力蛋白的纳米级运动以及力测量
DOI：
10.1242/jcs.1991.supplement_14.27
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发表时间：
1991
影响因子：
4
通讯作者：
M. Sheetz
中科院分区：
文献类型：
--
作者：
S. Kuo;J. Gelles;E. Steuer;M. Sheetz
我们对驱动蛋白和动力蛋白包被的乳胶珠的运动的详细测量揭示了马达的几个重要特征，这些特征是马达运动机制的基本机械方面的基础。驱动蛋白包被的珠子将以高保真度沿着单个微管原丝的路径沿着移动，并且在低ATP条件下将沿着微管轴以沿着4nm的间隔暂停。相比之下，细胞质动力蛋白包被的珠子在沿着微管沿着行进时横向移动穿过许多原丝，没有任何规律的停顿，这表明驱动蛋白包被的珠子的移动不是该方法的假象。这些驱动蛋白珠的运动提出了驱动蛋白运动的模型，其中两个头部以手牵手的方式沿着单个原丝行走。一个自由的头部只能与原丝上的下一个微管蛋白亚基结合，它的结合会拉下尾随的头部，重新开始循环。该模型与所观察到的头部之间的协同性和单个二聚体分子的运动是一致的。该模型的几个可测试的预测是，驱动蛋白应该能够结合α和β微管蛋白，并且分子的颈部区域的长度应该控制离轴运动性。在这篇文章中，我们描述了测量纳米级运动和驱动蛋白分子产生的力的技术。
Summary Our detailed measurements of the movements of kinesin- and dynein-coated latex beads have revealed several important features of the motors which underlie basic mechanical aspects of the mechanisms of motor movements. Kinesin-coated beads will move along the paths of individual microtubule protofilaments with high fidelity and will pause at 4nm intervals along the microtubule axis under low ATP conditions. In contrast, cytoplasmic dynein-coated beads move laterally across many protofilaments as they travel along the microtubule, without any regular pauses, suggesting that the movements of kinesin-coated beads are not an artefact of the method. These kinesin bead movements suggest a model for kinesin movement in which the two heads walk along an individual protofilament in a hand-over-hand fashion. A free head would only be able to bind to the next forward tubulin subunit on the protofilament and its binding would pull off the trailing head to start the cycle again. This model is consistent with the observed cooperativity between the heads and with the movement by single dimeric molecules. Several testable predictions of the model are that kinesin should be able to bind to both alpha and beta tubulin and that the length of the neck region of the molecule should control the off-axis motility. In this article, we describe the technology for measuring nanometer-level movements and the force generated by the kinesin molecule.
影响因子：
64.8
作者：
ASHKIN, A;DZIEDZIC, JM;YAMANE, T
通讯作者：
YAMANE, T