Functional Analysis of TorsinA

描述(由申请人提供)： 早发性扭转肌张力障碍是遗传性肌张力障碍中最常见和最严重的形式。这种疾病的许多病例与TorsinA蛋白中的单一氨基酸缺失有关。TorsinA是内质网中发现的一种AAA+ATPase，但其正常细胞功能及其在肌张力障碍发病机制中的作用尚不清楚。这个项目的目标是定义由TorsinA控制的细胞和分子事件，以便开始了解这种难以捉摸的疾病的病因。在初步研究中，我们使用了在培养细胞中表达的TorsinA突变体，并确定了TorsinA在ER的一个亚域，即核膜中可能具有的功能。该方案中的实验将探索TorsinA如何作为AAA+ATPase发挥作用，并确定其在核膜中的确切作用。 我们的具体目标是： 1.开发并实验测试TorsinA功能的结构模型，然后将其应用于理解与疾病相关的突变如何影响蛋白质功能。 2.研究肌动蛋白A在内质网和核膜中的动态和分布，验证核膜是其主要作用部位的假说。 3.确定核膜中Torsin A的分子靶点。

DESCRIPTION (provided by applicant): Early onset torsion dystonia is the most common and severe form of inherited dystonia. Many cases of this disease are associated with a single amino acid deletion in the protein torsinA. TorsinA is an AAA+ ATPase found in the endoplasmic reticulum, but its normal cellular function and role in the pathogenesis of dystonia are unknown. The goal of this project is to define cellular and molecular events controlled by torsinA in order to begin to understand the etiology of this elusive disease. In preliminary studies, we used torsinA mutants expressed in cultured cells and identified a likely function for torsinA in a subdomain of the ER, the nuclear envelope. Experiments in this proposal will explore how torsinA functions as an AAA+ ATPase and define its exact role in the nuclear envelope. Our specific aims are: 1. To develop and experimentally test a structural model for torsinA function, and then apply this to understanding how disease-linked mutations affect protein function. 2. To study torsinA dynamics and distribution in the endoplasmic reticulum and nuclear envelope to test the hypothesis that the nuclear envelope is its primary site of action. 3. To define the molecular targets of torsinA in the nuclear envelope.