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.

项目概要/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 基本上参与每个细胞过程。由于其核心作用，UPS 内部的监管不当可能会加剧或 导致疾病，例如神经退行性变和癌症。现在人们已经充分了解蛋白质错误折叠和 与神经退行性疾病密切相关的积累会损害 UPS，加剧 疾病。事实上，人们对寻找激活蛋白酶体功能的方法作为可能的治疗方法非常感兴趣。 神经退行性疾病。相反，在肿瘤疾病中，UPS 经常被利用甚至上调。到期的 为此，多发性骨髓瘤的一线治疗是蛋白酶体抑制。因此，UPS 处于共享且关键的地位 在这两种人类主要疾病中的地位。蛋白酶体——UPS 的核心降解机制——是 受非常不同的监管复合物（例如 19S、PA28、PA28、PA200 和推定的 P97）监管。这些人的工作 复合物的作用是调节蛋白酶体核心颗粒20S的功能，从而隔离其蛋白质降解 室从细胞环境。这些监管机构的一个共同点是，它们的作用都是诱导开放 20S 蛋白酶体底物门，将底物暴露于内部降解室。蛋白酶体，和 其监管机构提供了丰富的监管环境来开发可能对这两个大领域产生深远影响的疗法 的学习。这需要对所涉及的分子机制有深入的生化了解。最近的弹幕 蛋白酶体结构的研究促进了这一努力，但不了解其动态机制的结构 它们的功能是有限的。因此，该提案主要侧重于了解生化 这些不同的蛋白酶体复合物中的三种的功能并定义它们如何调节蛋白质降解。我们将 重点关注三个具体问题：1）蛋白酶体 ATP 酶的 N 端结构域如何影响蛋白酶体 功能？、2) 哺乳动物 P97 如何发挥作用来刺激 20S 蛋白酶体的蛋白质降解？、3) PA28如何调节20S功能催化核蛋白降解？我们选择重点关注这三个方面 调节剂，因为它们各自在其降解的底物类型中发挥着独特的作用，并且各自发挥着关键作用 在特定的人类疾病中。我们实施各种方法和系统来解决这些问题，包括 研究古细菌、酵母、线虫、哺乳动物和人类的蛋白酶体调节因子的功能。此外，我们 正在使用秀丽隐杆线虫作为动物模型系统来测试我们的生化衍生模型并进行基因测试治疗 概念。这项研究的成功完成将通过确定中心问题在该领域产生持续的影响。 这三种不同的细胞策略调节蛋白质降解的机制，每种策略发挥不同的作用 但在生物学和疾病中发挥着关键作用。