alpha-Synuclein Inhibition of Mitochondrial Protein Import

α-突触核蛋白抑制线粒体蛋白输入

基本信息

批准号：
9044369
负责人：
J Timothy Greenamyre
金额：
$ 36.04万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-09-15 至 2020-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9044369
关键词：
Affinity Autonomic Dysfunction Binding Cardiolipins Cells Cognitive Complex Consensus Sequence Defect Disease Dopamine Environmental Risk Factor Etiology Genetic Genome Genus Hippocampus Impairment Individual Lipids Maintenance Measures Mediating Membrane Mitochondria Mitochondrial Proteins Modification N-terminal Nature Nerve Degeneration Neurodegenerative Disorders Nitrates Outer Mitochondrial Membrane Parkinson Disease Pathogenesis Phosphorylation Point Mutation Post-Translational Protein Processing Power Plants Production Protein Import Proteins RNA Splicing Reactive Oxygen Species Respiration Signal Transduction Signaling Protein Solutions Substantia nigra structure Sulfhydryl Compounds Surveys Symptoms Synapses System Therapeutic Time Variant alpha synuclein base combat dopaminergic neuron genetic manipulation mitochondrial dysfunction motor impairment mutant nitration novel overexpression oxidation oxidative damage public health relevance receptor small hairpin RNA translocase

项目摘要

DESCRIPTION (provided by applicant): Parkinson disease (PD) is a common neurodegenerative disorder resulting in motor impairment, cognitive and psychiatric symptoms and autonomic dysfunction. Genetic and environmental factors have been implicated in PD pathogenesis, and it appears that mitochondrial defects and accumulation of the synaptic protein, α- synuclein, are common to most forms of the disease. Moreover, there is evidence of a bidirectional interaction between mitochondrial dysfunction and α-synuclein accumulation. Inhibition of mitochondrial complex I leads to accretion and oligomerization of α-synuclein, and increased levels of α-synuclein cause mitochondrial impairment and production of reactive oxygen species (ROS). The nature of the interaction between α- synuclein and mitochondria remains obscure, and it is unclear whether unmodified monomeric α-synuclein is responsible for these effects, or whether posttranslational modifications which have been implicated in pathogenesis, such as oligomerization, dopamine modification, phosphorylation or nitration are important. Mitochondria contain their own genome, but it encodes only 13 proteins, so they must import about 99% of the >1000 proteins they contain. Mitochondrial protein import occurs through complex and highly regulated systems, the best understood of which recognizes N-terminal mitochondrial targeting signals (MTS) on proteins destined for import. While there is no consensus sequence, MTS characteristically form an amphipathic helix that is recognized by a receptor protein, TOM20, which is a subunit of the translocase complex of the outer mitochondrial membrane (TOM). Although monomeric α-synuclein is an intrinsically disordered protein in solution, in association with anionic lipids in membranes, it forms an amphipathic helix similar to known MTS motifs. In this context, we have strong evidence that certain forms of posttranslationally-modified α-synuclein bind specifically to TOM20 and interfere with import of mitochondrially-targeted proteins. We propose to study the interaction of α-synuclein with mitochondrial import machinery in the following aims: (1) Define the specific forms of α-synuclein that inhibit mitochondrial protein import; (2) Define key binding partners and binding parameters; (3) Determine functional consequences of α-synuclein-induced impairment of mitochondrial protein import; (4) Investigate whether blockade of mitochondrial protein import causes nigrostriatal neurodegeneration similar to α-synuclein overexpression; and (5) Examine the potential for genetic manipulation of mitochondrial import to protect against AAV2-mediated α-synuclein overexpression in substantia nigra.

描述（由适用提供）：帕金森病（PD）是一种常见的神经退行性疾病，导致运动障碍，认知和精神病症状以及自主神经功能障碍。遗传和环境因素已在PD发病机理中浸渍，并且似乎大多数疾病形式的线粒体缺陷和突触蛋白α-突触核蛋白的积累是常见的。此外，有证据表明线粒体功能障碍与α-突触核蛋白积累之间存在双向相互作用。线粒体复合物I的抑制作用导致α-突触核蛋白的积聚和寡聚，并且α-突触核蛋白的水平升高会导致线粒体损伤和活性氧（ROS）的产生。 α-突触核蛋白和线粒体之间相互作用的性质仍然晦涩难懂，目前尚不清楚未修饰的单体α-突触核蛋白是否对这些作用负责，或者是否在发病后实施的转基因修饰，例如低聚物，多巴胺修饰，磷酸化或NITRARITION，诸如诸如低聚集，磷酸化或NItration之类的发病。线粒体包含自己的基因组，但仅编码13种蛋白质，因此它们必须进口约99％的> 1000蛋白。线粒体蛋白的导入是通过复杂且高度调节的系统发生的，这是对蛋白质上的N端线粒体靶向信号（MT）的最佳理解。虽然没有共识序列，但MTS特征在于由受体蛋白TOM20识别的两亲性螺旋，该螺旋是外部线粒体膜（TOM）的转运酶配合物的亚基。尽管单体α-突触核蛋白是溶液中本质上无序的蛋白类似于已知的MTS主题。在这种情况下，我们有强有力的证据表明，某些形式的翻译后修饰后α-突触核蛋白特异性与TOM20结合并干扰了线粒体靶向的蛋白。我们建议在以下目的中研究α-突触核蛋白与线粒体进口机械的相互作用：（1）定义抑制线粒体蛋白进口的α-突触核蛋白的特定形式；（2）定义密钥结合伙伴和绑定参数；（3）确定α-突触核蛋白诱导的线粒体蛋白进口损伤的功能后果；（4）研究线粒体蛋白进口的阻滞是否会导致黑质性神经变性类似于α-突触核蛋白过表达；（5）检查了对线粒体进口的遗传操纵的潜力，以防止黑质中的AAV2介导的α-突触核蛋白过表达。