Mechanisms regulating proteasomal substrate degradation

蛋白酶体底物降解的调节机制

• 批准号: 10022500
• 负责人: David Matthew Smith
• 金额: $ 30.4万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10022500
• 关键词: 26S proteasome; ATP phosphohydrolase; Address; Affect; Animal Model; Archaea; Binding; Binding Proteins; Biochemical; Biological; Biological Models; Biology; Caenorhabditis elegans; Catalysis; Cell Nucleus; Cell physiology; Cells; Charge; Coiled-Coil Domain; Complex; Data; Disease; Disulfides; Endoplasmic Reticulum Degradation Pathway; Eukaryota; Foundations; Goals; Hand; Homologous Gene; Human; Impairment; In Vitro; Interferons; Life; Malignant Neoplasms; Mammals; Maps; Mission; Modeling; Molecular; Molecular Conformation; Multiple Myeloma; Mutagenesis; N-terminal; Nematoda; Nerve Degeneration; Neurodegenerative Disorders; Nuclear; Nuclear Protein; Nuclear Proteins; Nucleosome Core Particle; Occupations; Peptide Hydrolases; Play; Positioning Attribute; Post-Translational Protein Processing; Process; Property; Proteasome Inhibition; Proteins; Public Health; Recombinants; Regulation; Research; Role; Site; Structure; System; TP53 gene; Testing; Ubiquitin; United States National Institutes of Health; Yeasts; base; biochemical model; c-myc Genes; crosslink; design; field study; human disease; in vitro Assay; in vivo; interest; multicatalytic endopeptidase complex; mutant; neoplastic; novel; protein degradation; protein misfolding; therapeutic development; therapeutic evaluation; therapy development; transcription factor

PROJECT SUMMARY/ABSTRACT The Ubiquitin Proteasome System (UPS) regulates the degradation of the majority of proteins in the cell and, as such, it is involved in essentially every cellular process. Because of its central role, misregulation within the UPS can potentiate or cause diseases, such as neurodegeneration and cancer. It is now well understood that protein misfolding and accumulation, which are intimately associated with neurodegenerative disease, can impair the UPS, exacerbating the disease. In fact, there is great interest to find ways of activating proteasome function as possible treatments for neurodegenerative disorders. To the contrary, in neoplastic disease the UPS is often exploited and even upregulated; due to this, a first line treatment for multiple myeloma is proteasome inhibition. The UPS thus sits at a shared and critical position in these two major human diseases. The proteasome—the central degradative machinery of the UPS—is regulated by very different regulatory complexes (e.g. 19S, PA28, PA28, PA200, and putatively P97). The job of these complexes is to regulate the function of the core particle of the proteasome, the 20S, which isolates its protein degradation chamber from the cellular milieu. A commonality shared by these regulators is that they all function to induce opening of the 20S proteasome substrate gate, which exposes substrates to the interior degradation chamber. The proteasome, and its regulators, provide a rich regulatory landscape to develop therapies that could profoundly impact these two large fields of study. This will require a deep biochemical understanding of the involved molecular mechanisms. The recent barrage of proteasomal structures facilitate this effort, but structures without an understanding of the dynamic mechanisms that underlie their functions are limited. Therefore, this proposal is primarily focused on understanding the biochemical function of three of these diverse proteasomal complexes and defining how they regulate protein degradation. We will focus on three specific questions: 1) How do the N-terminal domains of the proteasomal ATPases affect proteasome function?, 2) How does the mammalian P97 function to stimulate protein degradation by the 20S proteasome?, and 3) How does PA28 regulate 20S function to catalyze nuclear protein degradation? We have chosen to focus on these three regulators because they each play unique roles in the types of substrates that they degrade, and they each play key roles in specific human diseases. We implement a variety of approaches and systems to address these questions including studying function of proteasomal regulators from archaea, yeast, nematodes, mammals, and humans. Furthermore, we are using C. elegans as an animal model system to test our biochemically derived models and genetically test therapeutic concepts. The successful completion of this study will produce a sustained impact in the field by defining the central mechanisms of these three different cellular strategies for regulating protein degradation, each of which play different but critical roles in biology and disease.

项目摘要/摘要 泛素蛋白酶体系统(UPS)调节细胞中大多数蛋白质的降解，因此，它是 基本上参与了每一个细胞过程。由于UPS的核心作用，UPS内部的不当监管可能会加剧或 导致疾病，如神经退行性变和癌症。现在已经很好地理解了蛋白质的错误折叠和 与神经退行性疾病密切相关的积聚会损害UPS，加剧 疾病。事实上，寻找激活蛋白酶体功能的方法作为可能的治疗方法是非常有兴趣的。 神经退行性疾病。相反，在肿瘤疾病中，UPS经常被利用，甚至被上调； 对此，多发性骨髓瘤的一线治疗是蛋白酶体抑制。因此，UPS处于一个共享的和关键的 在这两大人类疾病中的地位。蛋白酶体--UPS的中央降解机制--是 受非常不同的调节复合体(例如19S、PA28、PA28、PA200和可能的P97)调控。这些人的工作是 复合体的作用是调节蛋白酶体的核心颗粒20S的功能，该颗粒隔离了蛋白质的降解 从蜂窝环境中分离出来。这些监管机构的一个共同点是，它们都起到了诱导开放 20S蛋白酶体底物门，将底物暴露在内部降解室中。蛋白酶体，以及 其监管机构提供了丰富的监管环境，以开发可能对这两大领域产生深远影响的疗法 在学习方面。这将需要对所涉及的分子机制有深入的生物化学理解。最近的炮击 蛋白酶体结构促进了这一努力，但结构不了解动态机制 根本原因是它们的功能有限。因此，这项建议主要集中在了解生化 其中三个不同的蛋白酶体复合体的功能，并确定它们如何调节蛋白质的降解。我们会 重点研究三个具体问题：1)蛋白酶体ATPase的N-末端结构域如何影响蛋白酶体 功能？2)哺乳动物P97如何通过20s蛋白酶体刺激蛋白质降解？3) PA28如何调节20S的功能以催化核蛋白降解？我们选择专注于这三个方面 调节剂，因为它们各自在它们降解的底物类型中扮演着独特的角色，而且它们各自扮演着关键角色 在特定的人类疾病中。我们实施了各种方法和系统来解决这些问题，包括 研究古生菌、酵母菌、线虫、哺乳动物和人类蛋白酶体调节因子的功能。此外，我们 正在使用线虫作为动物模型系统来测试我们的生物化学衍生模型和基因测试治疗 概念。这项研究的成功完成将在实地产生持续的影响，因为它界定了 这三种不同的细胞策略调节蛋白质降解的机制，每一种都发挥着不同的作用 但在生物学和疾病中起着关键作用。