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：
9279278
负责人：
J Timothy Greenamyre
金额：
$ 47.44万
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/9279278
关键词：
Affinity Autonomic Dysfunction Binding Cardiolipins Cells Characteristics 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 Neurobehavioral Manifestations Neurodegenerative Disorders Nitrates Outer Mitochondrial Membrane Parkinson Disease Pathogenesis Pathogenicity Phosphorylation Point Mutation Post-Translational Protein Processing Power Plants Production Protein Import Proteins RNA Splicing Reactive Oxygen Species Respiration Signal Transduction Signaling Protein Substantia nigra structure Sulfhydryl Compounds Surveys Synapses System Therapeutic Time Variant alpha synuclein combat dopaminergic neuron genetic manipulation mitochondrial dysfunction motor impairment mutant nitration novel overexpression oxidation oxidative damage psychiatric symptom 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（由申请人提供）：帕金森病（PD）是一种常见的神经退行性疾病，导致运动障碍、认知和精神症状以及自主神经功能障碍，遗传和环境因素与帕金森病的发病机制有关，并且线粒体缺陷和线粒体缺陷累积。突触蛋白 α-突触核蛋白在大多数疾病中都很常见，而且有证据表明线粒体功能障碍和 α-突触核蛋白积累抑制之间存在双向相互作用。 α-突触核蛋白的增加和寡聚化，以及 α-突触核蛋白水平的增加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不清楚，并且尚不清楚是否未修饰的单体。 α-突触核蛋白是造成这些效应的原因，或者与发病机制有关的翻译后修饰（例如寡聚化、多巴胺修饰、磷酸化或硝化）是否重要。线粒体含有自己的基因组，但它只编码 13 种蛋白质，因此它们所含有的超过 1000 种蛋白质中的 99% 必须通过它们导入。线粒体蛋白质导入是通过复杂且受调节的系统进行的，其中最容易理解的系统可识别高度 N 末端线粒体靶向。虽然没有共有序列，但 MTS 典型地形成一个被受体蛋白 TOM20 识别的两亲性螺旋，TOM20 是一个亚基。尽管单体 α-突触核蛋白在溶液中本质上是无序的蛋白质，但与膜中的阴离子脂质结合，它形成了两亲性螺旋。与已知的 MTS 基序类似，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的 α-突触核蛋白特异性结合 TOM20 并干扰线粒体靶向蛋白的输入。我们建议研究 α-突触核蛋白与线粒体的相互作用。导入机制的目标如下：(1) 定义抑制线粒体蛋白导入的 α-突触核蛋白的具体形式；(2) 定义关键结合伙伴和结合参数；(3) 确定功能后果； α-突触核蛋白诱导的线粒体蛋白输入受损；（4）研究线粒体蛋白输入的阻断是否会导致类似于 α-突触核蛋白过度表达的黑质纹状体神经变性；以及（5）检查线粒体输入的基因操作以防止 AAV2-介导黑质中 α-突触核蛋白过度表达。