Exploring DYT1 pathogenesis: torsinA and the nuclear envelope

描述(由申请人提供)：我的长期职业目标是了解神经疾病潜在的生物异常，并应用这些知识来改善患有这些疾病的患者的生活质量。在我的训练期间，我对遗传性口吃困难产生了浓厚的兴趣。肌张力障碍是一种神经综合征，其特征是经常被刻板印象的长时间扭曲的不自主运动。已经描述了几种肌张力障碍的遗传形式，其中DYT1是最常见的。我最初特别感兴趣，在博士后培训期间研究了DYT1肌张力障碍。我现在需要获得必要的技能来评估TorsinA的正常功能，DYT1中突变的蛋白质，以及它在培养细胞和动物模型中的疾病状态下的功能障碍。为了实现这一目标，我与几位科学家展开了合作，并将在爱荷华大学神经病学系内开展拟议中的工作。TorsinA是四种密切相关的哺乳动物Torsin蛋白之一。最近在DYT1研究中的一项突破表明，虽然正常情况下驻留在内质网(ER)中，但突变的TorsinA会在核膜(NE)中积累。从这个位置，TorsinA已被发现调节细胞质蛋白聚集成侵袭体。TorsinA在核膜中的作用是什么，突变时如何导致神经元功能障碍，如何调节侵袭性，以及哪些因素导致疾病外显性降低，这些仍然是悬而未决的问题。根据最近的报告和我自己的初步结果，我将直接回答这些问题。在目标1中，我将确定TorsinA如何调节NE蛋白的动态行为，并影响这个亚细胞结构的蛋白质组成。在目标2中，我将使用一种新的动态显微镜系统和基本的生物技术来定义TorsinA是如何影响攻击性形成的。在目标3中，我将使用RNA干扰来同时沉默培养细胞和体内不同的Torsin基因家族成员，以确定它们作为Torsin A诱导的功能障碍的调节器的潜在作用。该项目将提供有关TorsinA功能的重要信息，并可能揭示改变DYT1肌张力障碍外显率降低的因素，提供在所有突变携带者中预防疾病发展的治疗策略。这项建议体现了我在职业生涯中计划从事的临床相关基础神经生物学研究的类型。

DESCRIPTION (provided by applicant): My long-term career goal is to understand the biological abnormalities underlying neurological disorders and apply that knowledge to improve the quality of life of patients suffering from them. During my training period, I developed a strong interest on the inherited dystonias. Dystonia is a neurological syndrome characterized by prolonged twisting involuntary movements that are frequently stereotyped. Several genetic forms of dystonia have been described, being DYT1 the most common. I initially became specially interested and studied DYT1 dystonia during my postdoctoral training. I now need to acquire skills necessary to assess the normal function of torsinA, the protein mutated in DYT1, and its dysfunction in the disease state in cultured cells and animal models. To accomplish this goal, I have developed collaborations with several scientists and will pursue the proposed work within the Department of Neurology at The University of Iowa. TorsinA is one of four closely related mammalian torsin proteins. A recent breakthrough in DYT1 research demonstrated that, while normally residing in the endoplasmic reticulum (ER), mutant torsinA accumulates in the nuclear envelope (NE). From this location, torsinA has been found to modulate aggregation of cytoplasmic proteins into aggresomes. What is the role of torsinA in the nuclear envelope, how leads to neuronal dysfunction when mutated, how modulates aggresome and what factors condition the reduced penetrance of the disease remain unanswered questions. Building on recent reports and my own preliminary results, I will directly address those questions. In Aim 1, I will determine how torsinA modulates the dynamic behavior of NE proteins and influences the protein composition of this subcellular structure. In Aim 2, I will use a novel dynamic microscopy system and basic biological techniques to define how torsinA influences aggresome formation. In Aim 3, I will use RNA interference to simultaneously silence the different torsin gene family members in cultured cells and in vivo to determine their potential role as modulators of torsinA-induced dysfunction. This project will yield important information concerning the function of torsinA, and may uncover the factors that modify the reduced penetrance of DYT1 dystonia, providing therapeutic strategies to prevent the development of the disease in all mutation carriers. This proposal exemplifies the type of clinically related fundamental neurobiological research I plan to pursue during my career.