Function and Assembly of Eukaryotic Proteasomes

真核蛋白酶体的功能和组装

• 批准号: 9439805
• 负责人: Mark W Hochstrasser
• 金额: $ 33.94万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2020-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9439805
• 关键词: 26S proteasome; ABL1 gene; ATP phosphohydrolase; Address; Binding; Biochemical; Biogenesis; Biological; Biological Process; Cell Nucleus; Cells; Complex; Cytoplasmic Granules; DNA biosynthesis; Data; Diabetes Mellitus; Disease; Eukaryota; Exposure to; Factor Analysis; Genetic; Glucose; Goals; Grant; Growth; Heavy Metals; Heterodimerization; Human; Intervention; Laboratories; Link; Malignant Neoplasms; Measurement; Microscopy; Modeling; Modification; Molecular Chaperones; Multienzyme Complexes; Neurodegenerative Disorders; Nucleosome Core Particle; Pathway interactions; Pharmacologic Substance; Process; Proteasome Inhibitor; Protein Biosynthesis; Protein Isoforms; Proteins; Proto-Oncogene Proteins c-abl; RNA Processing; Resistance; Role; Saccharomyces cerevisiae; Specificity; Stress; Structure; Tissues; Tumor Suppressor Proteins; Work; Yeasts; anticancer treatment; base; biophysical techniques; cell type; experimental study; follow-up; genome-wide; human disease; in vivo; multicatalytic endopeptidase complex; mutant; novel; novel strategies; nucleocytoplasmic transport; particle; protein degradation; public health relevance; response

 DESCRIPTION (provided by applicant): Large protein machines control almost all biological processes, including DNA replication, RNA processing, and both protein synthesis and degradation. The 26S proteasome is responsible for the great majority of protein degradation in eukaryotes and is essential for numerous cellular pathways. Aberrant proteasomal activity impacts many human diseases, such as neurodegenerative disorders, cancer, and diabetes. Like many multisubunit catalytic complexes, the proteasome forms ring-shaped structures. The proteasome consists of a cylindrical 20S proteasome core particle (CP) with a 19S regulatory particle (RP) on one or both ends. In the CP, two outer heteroheptameric α rings sandwich a pair of β rings; the latter creates the central proteolytic chamber. Each RP can be divided into ld and base complexes. The RP base includes six ATPases that form a heterohexameric ring; the RP binds and unfolds substrates and drives them into the CP interior. How these large, essential complexes are assembled in vivo remains poorly understood. Proteasome assembly appears to be an ordered process conserved across species. As proteasomes are highly abundant, assembly must occur with high fidelity to avoid excessive accumulation of nonproductive and potentially toxic off-pathway intermediates. Both CP and RP assembly depend on dedicated assembly chaperones. The long-range goal of this grant is to delineate the pathways of eukaryotic 26S proteasome biogenesis. The proteasome has emerged as an important target for anti-cancer treatment and other therapies. Interfering with its assembly will provide a new approach for pharmaceutical intervention. The proposed experiments use a combination of genetic, biochemical, cell biological and biophysical methods and are focused primarily, but not entirely, on the model eukaryote Saccharomyces cerevisiae, which has a 26S proteasome very similar to the human complex. The first major goal will be to decipher the assembly-promoting mechanism of a putative novel CP assembly factor and how it interacts functionally with known CP assembly chaperones. A second goal is to determine how CPs with alternative α-subunit arrangements assembles in both yeast and human cells and to evaluate their functional significance. In a third aim, the focus is on a set of RP assembly chaperones (RACs) to determine their contributions to proper assembly of the ATPase ring of the RP base; the mechanism of RP lid-base joining will also be probed. Lastly, experiments will address how proteasome assembly is linked to import into the nucleus and how proteasomes in quiescent cells rapidly relocalize from cytoplasmic foci to the nucleus in response to glucose addition.

 描述（由申请人提供）：大型蛋白质机器控制几乎所有的生物过程，包括DNA复制、RNA加工以及蛋白质合成和降解。26 S蛋白酶体负责真核生物中绝大多数蛋白质的降解，并且是许多细胞途径所必需的。异常的蛋白酶体活性影响许多人类疾病，如神经退行性疾病、癌症和糖尿病。像许多多亚基催化复合物一样，蛋白酶体形成环状结构。蛋白酶体由一个圆柱形的20 S蛋白酶体核心颗粒（CP）和一端或两端的19 S调节颗粒（RP）组成。在CP中，两个外杂七聚体α环夹着一对β环;后者产生了中央蛋白水解室。每个RP可分为Id和碱络合物。RP碱基包括六个形成异六聚体环的ATP酶; RP结合并展开底物，并将其驱动到CP内部。这些大的、必需的复合物如何在体内组装仍然知之甚少。蛋白酶体组装似乎是一个有序的过程中保守的物种。由于蛋白酶体是高度丰富的，组装必须以高保真度发生，以避免非生产性和潜在毒性的途径外中间体的过度积累。CP和RP组装都依赖于专用的组装分子伴侣。这项资助的长期目标是描绘真核生物26 S蛋白酶体生物合成的途径。蛋白酶体已成为抗癌治疗和其他治疗的重要靶点。干扰其组装将为药物干预提供新的途径。拟议的实验结合使用遗传、生物化学、细胞生物学和生物物理方法，主要但不完全集中在模型真核生物酿酒酵母上，该酵母具有与人类复合体非常相似的26 S蛋白酶体。第一个主要目标将是破译一个假定的新CP组装因子的组装促进机制，以及它如何与已知的CP组装分子伴侣在功能上相互作用。第二个目标是确定具有替代α亚基排列的CP如何在酵母和人类细胞中组装，并评估其功能意义。在第三个目标中，重点是一组RP组装分子伴侣（RAC），以确定其对RP基地的ATP酶环的正确组装的贡献; RP盖基连接的机制也将被探讨。最后，实验将解决蛋白酶体组装是如何连接到输入到细胞核中，以及如何在静止细胞中的蛋白酶体迅速重新定位从细胞质病灶的细胞核中响应葡萄糖的添加。