Engagement and Communication Between Proteasonal Subcomplexes

蛋白酶子复合物之间的参与和交流

• 批准号: 9892109
• 负责人: ROBERT JOSEPH TOMKO
• 金额: $ 9.38万
• 依托单位: FLORIDA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9892109
• 关键词: ATP Hydrolysis; ATP phosphohydrolase; Active Sites; Affect; Alzheimer' s Disease; Antineoplastic Agents; Architecture; Area; Binding; Biochemical Genetics; Biogenesis; Biological Assay; Biology; Bortezomib; Catalysis; Cell Cycle; Cells; Cellular biology; Chemicals; Cleaved cell; Clinic; Communication; Complex; Coupled; Coupling; DNA Repair; Deubiquitinating Enzyme; Diabetes Mellitus; Disease; Drug resistance; Elements; Event; Garbage; Goals; Heart; Human; In Vitro; Individual; Inflammatory; Link; Macromolecular Complexes; Malignant Neoplasms; Mediating; Molecular; Molecular Biology; Molecular Conformation; Movement; Mutation; Neurodegenerative Disorders; Non-Insulin-Dependent Diabetes Mellitus; Nucleosome Core Particle; Nucleotides; Patients; Peptides; Process; Proteasome Inhibition; Proteasome Inhibitor; Proteins; Proteolysis; Recombinants; Reporter; Research; Role; Route; Signal Transduction; Structure; Testing; Velcade; Work; adaptive immunity; base; combinatorial; drug development; genetic approach; high throughput screening; human disease; in vivo; insight; multicatalytic endopeptidase complex; novel; novel therapeutics; protein degradation; protein misfolding; small molecule; small molecule inhibitor; tool

Project Summary/Abstract The proteasome is a multisubunit macromolecular machine that mediates most regulatory protein degradation and removes toxic proteins from cells. It is essential for activities as diverse as the cell cycle, adaptive immunity, and DNA repair. Alterations to proteasome activity impact numerous human diseases, including cancer, neurodegenerative disorders, and diabetes. The proteasome consists of three functional subcomplexes: the lid, the base, and the core particle. Each subcomplex performs distinct functions during substrate degradation. The lid removes the proteasomal targeting signal, the base uses energy from ATP hydrolysis to unfold the substrate, and the core particle then cleaves it into short peptides. These activities—as well as the subcomplexes that harbor them—are intimately linked by static and dynamic inter-subcomplex interactions. Recent structural studies have unexpectedly revealed that the proteasome exists in at least two well-defined conformational states—an apo state, in which the substrate passageways and the enzymatic active sites within these subcomplexes are blocked, and an engaged state, in which these passageways and active sites are opened and aligned, ready to accept and process substrates. Thus, these states reflect “off” and “on” conformations for the proteasome, respectively. Proteolytic inhibitors of the proteasome such as Velcade (bortezomib) are proven anticancer drugs, but resistance to these agents is already emerging. This necessitates alternative approaches to control proteasome function. Manipulation of the conformational state of the proteasome could allow for their selective activation or inactivation at will. This strategy could permit treatment of proteasome-addicted cancers via proteasome inactivation, as well as treatment of proteinopathies such as Alzheimer’s and type II diabetes, via enhancement of proteolysis to clear toxic inclusions. The long-term goal of this project is to understand the molecular mechanisms regulating engagement and communication between proteasomal subcomplexes, and how they relate to the proteasome’s conformational state. We seek to determine how individual conformation- specific contacts between lid and base subunits control proteasome structure and function (Aim1), dissect the critical role of nucleotide binding in reorganization of the lid-base interface to promote the engaged state (Aim 2), and to develop small molecules that disrupt lid-base coordination to be used as tools for studying proteasome function in human cells or in vitro (Aim 3). We anticipate our studies will yield insights into allosteric communication, energy use, and substrate processing by the proteasome, as well as yielding new information on proteasome biogenesis and structure. Further, the functional elements of the proteasome are found in many other multiprotein machines, so our studies could reveal general principles governing the function of diverse macromolecular complexes, and thus will impact numerous areas of cell and molecular biology.

项目总结/摘要 蛋白酶体是一个多亚基的大分子机器，介导大多数调节蛋白 降解并从细胞中去除有毒蛋白质。它对细胞周期等多种多样的活动至关重要， 适应性免疫和DNA修复蛋白酶体活性的改变影响许多人类疾病， 包括癌症、神经变性疾病和糖尿病。蛋白酶体由三种功能性的 子复合物：盖子，底座和核心颗粒。每个子复合体执行不同的功能， 基质降解盖子去除蛋白酶体靶向信号，底座使用来自ATP的能量 水解以解折叠底物，然后核心颗粒将其切割成短肽。这些活动，如 以及包含它们的子复合体-通过静态和动态的子复合体间紧密联系在一起 交互.最近的结构研究出乎意料地揭示了蛋白酶体存在于至少两个 明确定义的构象状态-载脂蛋白状态，其中底物通道和酶活性 这些亚复合体内的位点被阻断，并且处于接合状态，在该状态下，这些通道和活性物质被激活。 位置被打开并对准，准备接受和处理衬底。因此，这些状态反映“关”和“开” 蛋白酶体的构象。 蛋白酶体的蛋白水解抑制剂，如万珂（硼替佐米）是经证实的抗癌药物，但 对这些药剂的抗药性已经出现。这就需要其他方法来控制蛋白酶体 功能操纵蛋白酶体的构象状态可以允许它们的选择性激活或 随意灭活。这种策略可以通过蛋白酶体治疗蛋白酶体依赖性癌症 灭活，以及治疗蛋白质病，如阿尔茨海默氏症和II型糖尿病，通过增强 来清除有毒的内含物该项目的长期目标是了解分子 调节蛋白酶体亚复合物之间的接合和通讯的机制，以及如何 它们与蛋白酶体的构象状态有关。我们试图确定个体构造- 盖子和碱基亚基之间的特异性接触控制蛋白酶体的结构和功能（Aim 1）， 核苷酸结合在盖-碱基界面重组中的关键作用，以促进接合状态（目的 2），并开发破坏盖基配位的小分子，用作研究蛋白酶体的工具 在人细胞中或体外发挥作用（目的3）。我们预计我们的研究将有助于了解变构 蛋白酶体的通讯、能量利用和底物处理，以及产生新的信息 蛋白酶体的生物发生和结构。此外，蛋白酶体的功能元件存在于许多细胞中。 其他多蛋白质机器，所以我们的研究可以揭示管理不同蛋白质机器功能的一般原则。 大分子复合物，因此将影响细胞和分子生物学的许多领域。