Elucidation of the Biochemical Mechanism and In Vivo Functions of Spastin

描述(由申请人提供)： 该奖项的目的是完成我的培训，并在美国的一家学术机构建立一个高度跨学科的实验室，专注于细胞骨架调节机制的研究。我的实验室将采取一种全面、多方面的方法，将原子分辨率结构信息与体外和细胞内更大范围内的单分子动力学联系起来。该奖项的研究重点是剖析痉挛蛋白的生化和细胞机制。痉挛蛋白基因的突变是遗传性痉挛截瘫的主要原因，遗传性痉挛截瘫是一组鲜为人知的神经退行性疾病，以轴索病为特征。我发现spastin切断了微管(Roll-Mecak和Vale，2005)。疾病突变损害切断，将痉挛蛋白对微管细胞骨架的重塑与神经退化联系起来。这里概述的研究计划是高度跨学科的，整合了结构生物学、生物物理学和细胞生物学的技术和概念，以回答关于spastin功能的三个基本问题：1)spastin在其ATPase周期中的原子结构是什么，它是如何结合和破坏微管的；2)它是如何利用ATP水解的能量来分解微管的；3)spastin如何影响活细胞中的微管结构和动力学？当spastin耗尽或突变时，会产生什么细胞后果？尽管痉挛蛋白对神经元的存活很重要，但人们对其知之甚少。对其机制和基本细胞生物学的详细了解对于了解疾病的原因至关重要，这一建议为进一步开发治疗方法奠定了基本的机制基础。微管动力学和结构的扰动已经成为各种神经退行性疾病的共同主题，对痉挛蛋白的影响的了解将对所有这些疾病的病因产生影响。这项研究的目标是了解一种酶--痉挛蛋白的功能，这种酶在大多数遗传性痉挛截瘫患者中存在缺陷，这是一组知之甚少的神经退行性疾病。我发现，spastin破坏了细胞骨架的一个中心组成部分。这项研究将为开发治疗这类疾病所需的基本基础，也将增加我们对其他神经退行性疾病的了解。

DESCRIPTION (provided by applicant): The objective of this award is to complete my training and to establish a highly interdisciplinary lab at an academic institution in the U.S., focused on the study of the mechanism of cytoskeletal regulators. My lab will take a comprehensive, multifaceted approach by linking atomic resolution structural information with single molecule dynamics in vitro and in the larger context of the cell. The research focus of this award is to dissect the biochemical and cellular mechanisms of spastin. Mutations in the spastin gene are the leading cause of hereditary spastic paraplegias, a group of poorly understood neurodegenerative disorders characterized by axonopathy. I have discovered that spastin severs microtubules (Roll-Mecak and Vale, 2005). Disease mutations impair severing, linking spastin's remodeling of the microtubule cytoskeleton to neurodegeneration. The research plan outlined here is highly interdisciplinary, integrating techniques and concepts from structural biology, biophysics and cell biology to answer three fundamental questions about spastin function: 1) What is spastin's atomic structure throughout its ATPase cycle and how does it bind and break the microtubule; 2) How does it use the energy of ATP hydrolysis to disassemble the microtubule; and 3) How does spastin affect microtubule architecture and dynamics in the living cell and what are the cellular consequences incurred when spastin is depleted or mutated ? Despite its importance for neuronal survival very little is known about spastin. A detailed understanding of its mechanism and basic cell biology are critical to understanding the causes of the disease and this proposal sets the fundamental mechanistic groundwork that is needed to develop therapies further down the road. Perturbation of microtubule dynamics and architecture has emerged as a common theme in a variety of neurodegenerative diseases and an understanding of spastin's effects will have implications for the etiologies of all these disorders. Lay Summary: The goal of this research is to understand the function of an enzyme, spastin, that is defective in the majority of patients with hereditary spastic paraplegias, a group of poorly understood neurodegenerative disorders. I discovered that spastin breaks a central component of the cell's skeleton. This research will provide the basic groundwork needed for the development of treatments for this group of disorders and also increase our understanding of other neurodegenerative disorders.