Regulation of Cytoplasmic Dynein

细胞质动力蛋白的调节

• 批准号: 9206422
• 负责人: Andres Leschziner
• 金额: $ 29.56万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-10 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9206422
• 关键词: Regulation; Cytoplasmic; Dynein

DESCRIPTION (provided by applicant): The long-term goal of this research project is to understand how the microtubule (MT)-based motor cytoplasmic dynein ("dynein") is regulated. Dynein is the largest and most complex of all cytoskeletal motors; this >1 MDa dimeric complex contains numerous mechanical elements whose movements must be coordinated over strikingly long molecular distances to achieve processive motility along MTs. In addition to its enormous size, dynein is also the most versatile of the molecular motors; in sharp contrast to the 45 kinesins and 39 myosins present in humans, a single dynein gene product is responsible for transporting macromolecules within neurons, constructing the mitotic spindle, polarizing cells, and anchoring mRNAs during development. To give dynein the functional plasticity necessary for carrying out its many roles, several ubiquitous co-factors interact with dynein, including Lis1 and the dynactin complex. This project will apply our combined expertise in biochemistry, single-molecule biophysics and cryo-electron microscopy to address the structural and mechanistic bases of dynein's interaction with MTs and its regulation by Lis1 and dynactin. We recently showed that binding of dynein to MTs is accompanied by conformational changes in its MT- binding domain and that Lis1 acts as a "clutch" to uncouple MT binding and release from ATP hydrolysis, promoting a strongly MT-attached state. Dynactin, a 1.2 MDa complex, enhances dynein's processivity and is required for nearly all dynein functions in cells, but its mechanism o action is poorly understood. This grant will address major mechanistic questions about dynein and its regulation. What are the structural and mechanistic bases of MT binding (Aim 1), and of regulation by Lis1 (Aim 2) and dynactin (Aim 3)?

描述（由申请人提供）：该研究项目的长期目标是了解基于微管（MT）的运动细胞质动力蛋白（“动力蛋白”）是如何调节的。动力蛋白是所有细胞骨架马达中最大、最复杂的；这种 >1 MDa 二聚体复合物包含许多机械元件，其运动必须在极长的分子距离内协调，才能实现沿 MT 的加工运动。除了尺寸巨大之外，动力蛋白还是用途最广泛的分子马达。与人类体内存在的 45 种驱动蛋白和 39 种肌球蛋白形成鲜明对比的是，单个动力蛋白基因产物负责在神经元内运输大分子、构建有丝分裂纺锤体、极化细胞以及在发育过程中锚定 mRNA。为了赋予动力蛋白发挥其多种作用所需的功能可塑性，一些普遍存在的辅助因子与动力蛋白相互作用，包括 Lis1 和动力蛋白复合物。该项目将应用我们在生物化学、单分子生物物理学和冷冻电子显微镜方面的综合专业知识来解决动力蛋白与 MT 相互作用的结构和机制基础及其受 Lis1 和 dynactin 的调节。 我们最近表明，动力蛋白与 MT 的结合伴随着其 MT 结合域的构象变化，并且 Lis1 充当“离合器”来解开 MT 的结合和 ATP 水解的释放，从而促进强 MT 附着状态。 Dynactin 是一种 1.2 MDa 复合物，可增强动力蛋白的持续合成能力，并且是细胞中几乎所有动力蛋白功能所必需的，但其作用机制尚不清楚。这笔赠款将解决有关动力蛋白及其调节的主要机械问题。 MT 结合（目标 1）以及 Lis1（目标 2）和 dynactin（目标 3）调节的结构和机制基础是什么？