Mechanism of Microtubule Dynamics Regulation by Kinesins

动蛋白是真核细胞骨架蛋白，以其运动活性而闻名，但它们 也是微管动力学的重要调节者，即微管聚合物生长的能力 或者是心理医生。本项目旨在建立微管动力学的分子机制。 动蛋白超家族成员的调控。它们对微管动力学的调节作用 动蛋白在多种细胞过程中发挥着重要作用，如有丝分裂、胞质分裂、神经 纤毛和中心粒长度的发育和控制，但它们的机制 运动蛋白对微管的稳定或不稳定仍不清楚。目前还不知道有多大不同 Kinesin可能适用于看似不同的功能，或者它们是否具有共同的功能 机械装置。为了解决这一问题，我们建议进行比较结构和 几种具有不同功能的动蛋白的功能分析：微管解聚酶 KLP10A(Kinesin-13)、运动性和微管稳定剂KIF14(Kinesin-3)和EG5(Kinesin-3)。 5)和KIF5B中的典型运动运动蛋白(kinesin-1)。该提案分为四个目标。 前两个目的是基于我们最近的工作验证假设，即相同的ATPase与 运动蛋白-1s运动域中发生的构象变化适应于运动蛋白-13s 解聚微管。第二个目的是研究EG5的作用机制。 促进微管聚合，抑制解聚。第四个目标使用冷冻机- EM结构分析用于指导KIF14靶向药物的开发和优化 研究和潜在的临床应用。

Kinesins are eukaryotic cytoskeletal proteins best known for their motile activity, but they are also important regulators of microtubule dynamics, the ability of the microtubule polymer to grow or shrink. This project seeks to establish the molecular mechanism of microtubule dynamics regulation by members of the kinesin superfamily. Regulation of microtubule dynamics by these kinesins play important roles in a variety of cell processes such as mitosis, cytokinesis, neural development and control of cilia and centriole length, but the mechanisms by which these kinesins stabilize or destabilize microtubules is still not clear. It is not known how different kinesin may be adapted for seemingly different functionalities or whether they share common mechanisms. To address this issue we propose to conduct comparative structural and functional analysis of several kinesins with distinct functionalities: the microtubule depolymerase KLP10A (kinesin-13), the motile and microtubule stabilizers KIF14 (kinesin-3) and EG5 (kinesin- 5) and the archetypical motile kinesin KIF5B (kinesin-1). The proposal is divided in four aims. The first two aims test the hypothesis based on our recent work that the same ATPase related confomational changes occurring in the motor domain of kinesin-1s are adapted in kinesin-13s to depolymerize microtubules. The second aim investigates the mechanism by which EG5 promotes microtubule polymerization and inhibits depolymerization. The fourth aim uses cryo- em structural analysis to guide the development and optimization of KIF14 specific drugs for research and potentially clinical use.