Role of Parkin in Familial and Idiopathic Parkinson's Disease

描述（由申请人提供）：帕金森病（PD）是一种进行性神经退行性疾病，其特征在于黑质神经元的近选择性丧失。虽然该疾病的病因尚不清楚，但导致家族性PD的基因突变可能为特发性疾病的潜在机制提供关键的分子线索。泛蛋白E3连接酶帕金蛋白的功能缺失突变是常染色体隐性遗传性PD的最常见原因。Parkin现在被广泛认为是一种在细胞损伤期间快速上调的促存活蛋白。帕金被认为对线粒体生物学具有广泛的影响，可能与特发性PD相关。然而，这些影响的生化底物在很大程度上是未知的。我们工作的长期目标是揭示帕金影响线粒体的分子机制。这些信息不仅将提高我们对一个重要的神经元应激反应蛋白的理解，而且还将阐明可能参与PD选择性神经变性的新的生化途径。本申请的实验重点是由帕金神经元缺陷引起的线粒体缺陷，并确定负责的蛋白质。有三个具体目标。1)分析参与线粒体分裂和凋亡的两种新型帕金底物的帕金依赖性泛素化。我们将确定内源性帕金对蛋白质半衰期和定位的影响，以及这些候选底物对帕金缺陷神经元线粒体缺陷的贡献。2)分析原代培养神经元中parkin缺乏的线粒体后果，并检查parkin无效神经元对与特发性PD有关的应激源的增强的脆弱性。3)检查发生在parkin缺陷神经元中的蛋白质运输和功能的特异性变化。这些研究的完成将建立帕金的E3连接酶活性与其作为具有线粒体影响的促生存应激反应蛋白的功能之间的机制联系。这项工作将阐明参与PD发病机制的新生化途径，并可能发现治疗干预的创新靶点。 公共卫生相关性：帕金在保护性神经元应激反应中起关键作用，并与家族性帕金森病有因果关系。这项研究的目的是了解帕金维持线粒体完整性的确切机制，并确定可能导致帕金森病的分子事件。这些通路一旦被发现，可能会为治疗这种毁灭性的神经系统疾病确定新的治疗靶点。

DESCRIPTION (provided by applicant): Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the near selective loss of neurons in the substantia nigra. While the etiology of the disease is unknown, genetic mutations responsible for familial forms of PD will likely provide critical molecular clues to the underlying mechanisms of idiopathic disease. Loss-of-function mutations in the ubiquitin E3 ligase parkin are the most common cause of autosomal recessive PD. Parkin is now widely recognized as a pro-survival protein rapidly up-regulated during cell injury. Parkin is believed to possess broad ranging effects on mitochondrial biology that are likely relevant to idiopathic PD. However, the biochemical substrates of these effects are largely unknown. The long-term goal of our work is to uncover the molecular machinery responsible for parkin's influence on mitochondria. This information will not only improve our understanding of an important neuronal stress response protein but will also elucidate new biochemical pathways likely involved in the selective neurodegeneration in PD. The experimental focus of this application is on the mitochondrial defects that result from neuronal deficiencies in parkin and identifying the proteins responsible. There are three specific aims. 1) Analyze the parkin-dependent ubiquitination of two novel parkin substrates involved in mitochondrial fission and apoptosis. We will determine the effects of endogenous parkin on protein half-life and localization, and the contribution of these candidate substrates on mitochondrial defects in parkin deficient neurons. 2) Analyze the mitochondrial consequences of parkin deficiency in primary cultured neurons, and examine enhanced vulnerabilities of parkin null neurons to stressors implicated in idiopathic PD. 3) Examine mitochondria-specific changes in protein trafficking and function that occur in parkin deficient neurons. The completion of these studies will establish mechanistic links between the E3 ligase activity of parkin and its function as a pro-survival stress response protein with mitochondrial influence. This work will elucidate novel biochemical pathways involved in the pathogenesis of PD and potentially uncover innovative targets for therapeutic intervention. PUBLIC HEALTH RELEVANCE: Parkin is critically involved in a protective neuronal stress response and is causally linked to familial Parkinson's disease. The goal of this study is to understand the precise mechanisms by which parkin maintains integrity of the mitochondria and to define molecular events that can cause Parkinson's disease. These pathways, once discovered, may identify new therapeutic targets for the treatment of this devastating neurological disorder.