Biology of Parkin and It's Role in Parkinson's Disease

项目概要-项目1：帕金森病的生物学及其在帕金森病中的作用 帕金森病（PD）是一种复杂的神经退行性疾病，既有散发性，又有家族性。 parkin基因突变是常染色体隐性遗传性PD最常见的原因。在散发性多巴胺能帕金森病中， 氧化和亚硝化应激以及c-Abl磷酸化导致parkin的抑制。因此， parkin功能对于家族性和散发性PD都是基本的。Parkin是一种E3连接酶，这种功能丧失导致 底物AIMP2和PARIS的积累。我们已经发现，AIMP2表达导致年龄增长， 由于parthanatos依赖DA神经变性。PARIS的表达可能会导致 线粒体质量控制促进神经退化。 我们的假设是，在散发性PD中，亚硝化/氧化应激和c-Abl激活导致parkin失活， 导致Y143上parkin的磷酸化（pY143 parkin）和失活，随后积累 parkin底物，线粒体质量控制损失和毒性。同时，α-突触核蛋白被磷酸化， 在Y39（pY39 α-突触核蛋白）上，导致聚集和随后的毒性。由于聚集的α-突触核蛋白 会导致线粒体功能障碍，形成一个前馈循环 目的1：PD的统一特征之一是线粒体功能障碍。这一目标将探讨国际- PARIS与parkin突变引起的线粒体功能障碍的关系我们已经证明 PARIS是帕金森病中parkin的重要病理生理底物，其转录抑制PGC-1 α a 调节线粒体生物发生和线粒体氧化应激的主要转录辅激活因子 应答 目的2：parkin的失活导致AIMP2和PARIS的积累。AIMP2的表达 或PARIS足以促进年龄依赖性DA神经变性。事件的顺序激活了 PARIS和AIMP2将探索这两种蛋白质是否以及如何相互作用以启动细胞 死亡程序，parthanatos。 目的3：我们在A53T α-synuclein转基因小鼠中观察pY143 parkin和升高的AIMP2和PARIS， 这就提出了一个问题，即parkin失活、PARIS和AIMP2上调以及PARP1激活是否在 在α-突触核蛋白诱导的神经变性中的作用？这种可能性将与α-突触核蛋白探索 PD的预成型原纤维（PFFs）模型。 目的4：最先进的技术，包括深度测序和SILAM（通过氨基稳定同位素标记） 哺乳动物中的氨基酸）将被用于鉴定由成人条件性生长因子调控的基因和蛋白质。 parkin的敲除及其与PARIS诱导的关系，目的是识别信号中的节点 神经退行性疾病的级联反应，可以为PD的治疗提供新的靶点。

PROJECT SUMMARY - PROJECT 1: BIOLOGY OF PARKIN AND ITS ROLE IN PARKINSON'S DISEASE Parkinson's disease (PD) is a complex neurodegenerative disorder that is both sporadic and familial. Mutations in parkin are the most common cause of autosomal recessive PD. In sporadic PD dopaminergic, oxidative and nitrosative stress as well as c-Abl phosphorylation result in inhibition of parkin. Thus, loss of parkin function is elemental to both familial and sporadic PD. Parkin is an E3 ligase, this loss of function leads to accumulation of the substrates, AIMP2 and PARIS. We have found that AIMP2 expression leads to age dependent DA neurodegeneration due to parthanatos. And PARIS expression may lead to loss of mitochondrial quality control that promotes neurodegeneration. Our hypothesis is that parkin inactivation in sporadic PD by nitrosative/oxidative stress, and c-Abl activation leads to phosphorylation of parkin on Y143 (pY143 parkin) and inactivation followed by the accumulation of parkin substrates, loss of mitochondrial quality control and toxicity. In parallel, α-synuclein is phosphorylated on Y39 (pY39 α-synuclein) resulting in aggregation and subsequent toxicity. Since aggregated α-synuclein can lead to mitochondrial dysfunction it creates a feed forward cycle. Aim 1: One of the unifying features of PD is mitochondrial dysfunction. This aim will explore the inter- relationship of PARIS and mitochondrial dysfunction caused by mutations in parkin. We have shown that PARIS is an important pathophysiologic substrate of parkin in PD that transcriptionally represses PGC-1α a major transcriptional co-activator that regulates mitochondrial biogenesis and mitochondrial oxidant stress responses. Aim 2: Inactivation of parkin results in accumulation of both AIMP2 and PARIS. Expression of either AIMP2 or PARIS is sufficient to promote age dependent DA neurodegeneration. The sequence of events activated by PARIS and AIMP2 will be explored to determine if and how these two proteins interact to initiate the cell death program, parthanatos. Aim 3: We observe pY143 parkin and elevated AIMP2 and PARIS in A53T α-synuclein transgenic mice that raises the question of whether parkin inactivation, PARIS and AIMP2 upregulation and PARP1 activation play a role in α-synuclein induced neurodegeneration? This possibility will be explored with the α-synuclein preformed fibrils (PFFs) model of PD. Aim 4: State-of-the-art technology including deep sequencing and SILAM (stable isotope labeling by amino acids in mammals) will be deployed to identify genes and proteins that are regulated by adult conditional knockout of parkin and their relationship to PARIS induction with the goal of identify nodal points in the signal cascade of neurodegeneration that can provide new targets for the treatment of PD.