Molecular mechanisms of Parkin-directed mitochondrial quality control

Parkin介导的线粒体质量控制的分子机制

• 批准号: 9120949
• 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
• 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/9120949
• 关键词: Address; Affect; Aging; Animals; Appearance; Biochemical; Bioenergetics; Biological; Biological Assay; Biological Process; Biology; Brain region; Caenorhabditis elegans; Cell Aging; Cell Death; Cell Line; Cells; Cellular Stress; Charge; Chemicals; Crystallization; DNA; Data; Degradation Pathway; Dependence; Disease; Drug Design; 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; 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; brain cell; cell type; design; in vivo; in vivo Model; induced pluripotent stem cell; innovation; insight; mitochondrial dysfunction; molecular dynamics; novel; parkin gene/protein; parkin protein; prevent; protein misfolding; response; symptom treatment; ubiquitin ligase; ubiquitin-protein ligase; virtual

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。原因仍然是谜，因此停止或预防PD的治疗方法不可用。过去几年一直非常令人兴奋，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。到目前为止，该途径连接了三个帕金森病相关基因，PINK 1 PARKIN和FBXO 7，以及参与疾病发病机制的两个主要细胞功能障碍：mt功能障碍和降解途径受损。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PINK 1特异性地在受损的线粒体上积累时，帕金被招募来催化线粒体底物的差异泛素化。然而，帕金的酶功能，其E2辅因子，形成的泛素链的拓扑结构和它们的生物学作用仍然是谜。鉴于最近解决的结构帕金和其'封闭'的自抑制构象，我们建议，帕金被依次激活，释放其泛素连接酶的功能。我们已经确定了选择E2酶，调节帕金的激活及其酶功能，令人兴奋地通过不同的和相反的机制。鉴于几个治疗的机会可能存在沿着帕金激活级联反应，我们将进行这种神经保护蛋白的结构-功能分析。此外，线粒体中错误折叠蛋白质的积累可以作为PINK 1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）最近被描述为保守的长寿机制。我们建议阐明（中）激活机制的帕金的功能上的结构，分子，细胞和有机体水平。所以我们会 使用尖端技术，并将联合收割机计算、功能生化和细胞生物学与人类iPSC衍生神经元和体内C.优美的基于初步数据，我们假设帕金是通过mtUPR激活的，受生物能量学调节，并与保守的衰老途径相结合。在分子和结构水平上，帕金是由翻译后修饰，构象重排和选择E2辅酶控制。具体而言，我们将1）解开在健康和疾病中激活Parkin的生物学和分子机制; 2）确定Parkin的生理E2辅酶，它们的调节作用和对PD的贡献; 3）确定Parkin的活性及其与生物能量学和衰老途径的相互作用。拟议的研究是相关的，以充分认识帕金森病指导的线粒体质量控制的疾病干预的生物学意义和潜力，并揭示重要的机制的见解，将提供合理的药物设计的基础。