Molecular mechanisms of Parkin-directed mitochondrial quality control

Parkin介导的线粒体质量控制的分子机制

基本信息

批准号：
9326339
负责人：
Wolfdieter Springer
金额：
$ 34.23万
依托单位：
MAYO CLINIC JACKSONVILLE
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-01 至 2019-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9326339
关键词：
Address Affect Aging Alpha Cell Animals Appearance Biochemical Bioenergetics Biological Biological Assay Biological Process Biology Brain Brain region Caenorhabditis elegans Cell Aging Cell Death Cell Line Cells Cellular Stress Charge Chemicals Crystallization DNA Data Degradation Pathway Dependence Disease Drug Design Drug Targeting Enzymes FBXO7 gene Fibroblasts Financial compensation Functional disorder Genes Genetic Genetic study Health Human Image Imaging Device Impairment In Vitro Interferometry Intervention Kinetics Knock-out Label Laboratories Lead Ligation Link Longevity Lysine Methods Mitochondria Modeling Molecular Molecular Conformation Mutation Neurons Organelles PINK1 gene Parkinson Disease Parkinsonian Disorders Pathogenesis Pathway interactions Patients Phenotype Phosphotransferases Physiological Play Post-Translational Protein Processing Process Proteins Quality Control Recruitment Activity Regulation Role Sampling Signal Transduction Specimen Stimulus Structure Technology Therapeutic Tissues UBE2D2 gene Ubiquitin Ubiquitination Validation base biochemical tools cell type design disorder control in vivo induced pluripotent stem cell innovation insight misfolded protein mitochondrial dysfunction molecular dynamics novel parkin gene/protein parkin protein prevent public health relevance response symptom treatment ubiquitin ligase ubiquitin-protein ligase virtual

项目摘要

DESCRIPTION (provided by applicant): Parkinson's disease (PD) is a devastating disorder for which to date only symptomatic treatments exist. The causes remain enigmatic and thus therapeutics that halt or prevent PD are not available. The last few years have been extremely exciting due to the discovery of a novel mitochondrial quality control (mtQC) pathway by our laboratory and others. By now, this pathway links three parkinsonism associated genes, PINK1 PARKIN, and FBXO7, as well as the two major cellular dysfunctions involved in disease pathogenesis: mt dysfunction and impairment of degradation pathways. The mtQC pathway is thought to facilitate the elimination of dysfunctional organelles that would otherwise cause further cellular damage. However, (patho-) physiological relevant triggers of this pathway, particular in disease-relevant cells and in vivo are unclear. Upon accumulation of the kinase PINK1 specifically on damaged mitochondria, Parkin is recruited to catalyze differential ubiquitinations of mitochondrial substrates. However, Parkin's enzymatic functions, its E2 co-factors, the topologies of formed ubiquitin chains and their biological roles remain enigmatic. Given the recently resolved structure of Parkin and its 'closed' auto-inhibited conformation, we suggest that Parkin is sequentially activated to unleash its ubiquitin ligase functions. We have identified select E2 enzymes that regulate Parkin's activation and its enzymatic functions, excitingly through different and opposing mechanisms. Given that several therapeutic opportunities may exist along Parkin's activation cascade, we will perform structure-function analyses of this neuroprotective protein. Further, the accumulation of misfolded proteins in mitochondria may act as a physiological stimulus for PINK1 and Parkin activation. Strikingly, the induced mt- specific unfolded protein response (mtUPR) has very recently been described as a conserved longevity mechanism. We propose to elucidate the (in-) activation mechanisms of Parkin's functions on the structural, molecular, cellular, and organismal level. Therefore, we will use cutting-edge technologies and combine computational, functional biochemical and cell-biological with genetic methods in human iPSC-derived neurons and in vivo in C. elegans. Based on preliminary data, we hypothesize that Parkin is activated through the mtUPR, is regulated by bioenergetics and integrates with conserved aging pathways. On the molecular and structural level, Parkin is controlled by post-translational modifications, conformational rearrangements and by select E2 co-enzymes. Specifically, we will 1) unravel biological and molecular mechanism that (in)-activate Parkin in health and disease; 2) determine Parkin's physiological E2 co-enzymes, their regulatory roles and contribution to PD; 3) determine Parkin's activity(ies) and their interplay with bioenergetics and aging pathways. The proposed studies are relevant to fully appreciate the biological significance and potential of Parkin-directed mitochondrial quality control for disease intervention and to uncover important mechanistic insights that will provide the basis for rationale drug design.

描述（由申请人提供）：帕金森病（PD）是一种破坏性疾病，迄今为止仅存在对症治疗。其原因仍然是个谜，因此尚无阻止或预防帕金森病的治疗方法。由于我们的实验室和其他人发现了一种新的线粒体质量控制（mtQC）途径，过去几年非常令人兴奋。到目前为止，该通路连接了三个帕金森病相关基因 PINK1 PARKIN 和 FBXO7，以及疾病发病机制中涉及的两种主要细胞功能障碍：mt 功能障碍和降解通路受损。 mtQC 途径被认为有助于消除功能失调的细胞器，否则会导致进一步的细胞损伤。然而，该途径的（病理）生理相关触发因素，特别是在疾病相关细胞和体内，尚不清楚。当激酶 PINK1 在受损线粒体上特异性积累时，Parkin 被招募来催化线粒体底物的差异泛素化。然而，Parkin 的酶功能、其 E2 辅因子、形成的泛素链的拓扑结构及其生物学作用仍然是个谜。鉴于最近解析的 Parkin 结构及其“封闭”自抑制构象，我们建议依次激活 Parkin 以释放其泛素连接酶功能。令人兴奋的是，我们已经通过不同且相反的机制确定了一些 E2 酶，它们可以调节 Parkin 的激活及其酶功能。鉴于帕金激活级联过程中可能存在多种治疗机会，我们将对这种神经保护蛋白进行结构功能分析。此外，线粒体中错误折叠蛋白的积累可能作为 PINK1 和 Parkin 激活的生理刺激。引人注目的是，诱导的 mt 特异性未折叠蛋白反应 (mtUPR) 最近被描述为一种保守的长寿机制。我们建议在结构、分子、细胞和有机体水平上阐明 Parkin 功能的（内）激活机制。因此，我们将使用尖端技术，并将计算、功能生化和细胞生物学与遗传方法相结合，研究人类 iPSC 衍生的神经元和线虫体内。根据初步数据，我们假设 Parkin 通过 mtUPR 激活，受生物能量学调节，并与保守的衰老途径整合。在分子和结构水平上，Parkin 受翻译后修饰、构象重排和选择的 E2 辅酶控制。具体来说，我们将 1) 揭示在健康和疾病中激活 Parkin 的生物和分子机制； 2）确定Parkin的生理E2辅酶、其调节作用以及对PD的贡献； 3) 确定帕金活性及其与生物能量学和衰老途径的相互作用。拟议的研究有助于充分认识帕金导向的线粒体质量控制对疾病干预的生物学意义和潜力，并揭示重要的机制见解，为药物设计的基本原理提供基础。