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Mechanisms of Chaperone-Mediated Control in the Assembly of the Proteasome Holoenzyme

蛋白酶体全酶组装中分子伴侣介导的控制机制

基本信息

批准号：
10457366
负责人：
Soyeon Park
金额：
$ 31.75万
依托单位：
UNIVERSITY OF COLORADO
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10457366
关键词：
ATP Hydrolysis ATP phosphohydrolase Affect Aging Binding Binding Sites Biochemical Biological Biological Assay Cell physiology Cells Complex Critical Pathways Data Dependence Development Disease Escherichia coli Event Goals Growth Health Holoenzymes Human In Vitro Link Malignant Neoplasms Mediating Mediator of activation protein Medical Modeling Molecular Chaperones Molecular Machines Nerve Degeneration Neurodegenerative Disorders Nucleosome Core Particle Nucleotides Outcome Pathologic Pathway interactions Phenotype Polyubiquitination Process Proteins Proteolysis Public Health Publishing Quality Control Regulation Research Role Route Saccharomycetales Syndrome System Testing Time Ubiquitin Ubiquitination Variant Work Yeast Model System Yeasts base cell growth combat human disease in vivo innovation multicatalytic endopeptidase complex mutant new therapeutic target prevent protein degradation reconstitution therapeutic target ubiquitin-protein ligase yeast genetics

项目摘要

PROJECT SUMMARY The proteasome is a complex molecular machine and an essential mediator of ubiquitin-dependent protein degradation. Polyubiquitination of target proteins has been long considered the major regulator of proper protein degradation. However, little is known about a new and potent regulator of cellular protein degradation — mechanisms that control the rate and quality of proteasome assembly. It is well established that cells require multiple evolutionarily conserved chaperones to regulate proteasome assembly. A catalyzed assembly mechanism serves as an active regulator of proper proteasome assembly, and therefore of proteolysis itself. Under some pathological situations, cells are known to exploit these chaperones to alter the rate of proteasome- mediated proteolysis. Moreover, chaperone-mediated assembly of proteasomes has also been linked to major pathways for growth control. Therefore, understanding how chaperones control proteasome assembly is of wide- ranging biological and biomedical significance. The objective of this proposal is to elucidate how these chaperones function to regulate the rate and the quality of proteasome formation. Our central hypothesis is that the chaperones determine correct versus incorrect assembly of the proteasome by regulating both the ATP hydrolysis and the ubiquitination of the ATPase subunits en route to proteasome formation. Aim 1 will determine how chaperone-mediated inhibition of ATP hydrolysis by the proteasome subunits controls proteasome assembly events. Both in vitro and in vivo proteasome assembly assays will be used while the ATPase rates are directly modulated by specific yeast mutants. Aim 2 will determine how ubiquitinations of the proteasome subunits provide quality control during chaperone-mediated proteasome assembly. Biochemical approaches similar to Aim 1 will be used in combination with yeast genetics. The goal is to identify how the chaperones regulate ubiquitination of the proteasome subunits, and how ubiquitination affects assembly intermediates and the assembled proteasome holoenzyme. The expected outcome is the identification of the mechanisms by which the chaperones determine incorrect versus correct assembly events, and provide quality control, thereby enabling only the correct assembly events to proceed in forming the proteasome holoenzyme. The proposed research is innovative because it aims to identify mechanisms that regulate the number of functional proteasomes in the cell, which have been missing from the current paradigm of proteasome-mediated proteolysis. This contribution is significant for human health to help understand how this critical pathway is exploited to alter protein degradation in pathological conditions, including cancer, neurodegenerative disease and aging. These conditions are known to be impacted by the ubiquitin-proteasome system, a proven therapeutic target for altering protein degradation in disease. We anticipate that understanding chaperone-mediated regulation of the proteasome subunits will contribute to the development of new targeted drugs.

项目概要蛋白酶体是一种复杂的分子机器，是泛素依赖的重要介质蛋白质降解。长期以来，靶蛋白的多泛素化一直被认为是正确的主要调节因子。蛋白质降解。然而，人们对细胞蛋白质降解的新的有效调节剂知之甚少—— 控制蛋白酶体组装速率和质量的机制。众所周知，细胞需要多个进化上保守的伴侣来调节蛋白酶体组装。催化组装该机制作为适当蛋白酶体组装的主动调节剂，因此也是蛋白水解本身的主动调节剂。在某些病理情况下，已知细胞利用这些伴侣来改变蛋白酶体的速率介导的蛋白水解作用。此外，伴侣介导的蛋白酶体组装也与主要的生长控制途径。因此，了解伴侣如何控制蛋白酶体组装具有广泛的意义。具有广泛的生物学和生物医学意义。该提案的目的是阐明这些分子伴侣的作用是调节蛋白酶体形成的速度和质量。我们的中心假设是分子伴侣通过调节 ATP 来确定蛋白酶体的正确与错误组装 ATP酶亚基在蛋白酶体形成过程中的水解和泛素化。目标1将决定伴侣介导的蛋白酶体亚基对 ATP 水解的抑制如何控制蛋白酶体集会活动。将使用体外和体内蛋白酶体组装测定，同时 ATP 酶速率为由特定酵母突变体直接调节。目标 2 将确定蛋白酶体如何泛素化亚基在伴侣介导的蛋白酶体组装过程中提供质量控制。生化方法与目标 1 类似，将与酵母遗传学结合使用。目标是确定伴侣如何调节蛋白酶体亚基的泛素化，以及泛素化如何影响组装中间体和组装的蛋白酶体全酶。预期结果是确定机制伴侣确定不正确与正确的组装事件，并提供质量控制，从而仅使正确的组装事件能够继续形成蛋白酶体全酶。拟议的研究具有创新性，因为它的目的是确定调节功能性细胞数量的机制。细胞中的蛋白酶体，这是目前蛋白酶体介导的蛋白水解范例中所缺失的。这一贡献对于人类健康具有重要意义，有助于了解如何利用这一关键途径来改变病理条件下的蛋白质降解，包括癌症、神经退行性疾病和衰老。这些已知疾病受到泛素蛋白酶体系统的影响，泛素蛋白酶体系统是一种经过验证的治疗靶点，可以改变疾病中的蛋白质降解。我们预计，了解伴侣介导的调节蛋白酶体亚基将有助于新靶向药物的开发。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Assembly checkpoint of the proteasome regulatory particle is activated by coordinated actions of proteasomal ATPase chaperones.

DOI：
10.1016/j.celrep.2022.110918
发表时间：
2022-06-07
期刊：
CELL REPORTS
影响因子：
8.8
作者：
Nahar, Asrafun;Sokolova, Vladyslava;Sekaran, Suganya;Orth, James D.;Park, Soyeon
通讯作者：
Park, Soyeon

Two alternative mechanisms regulate the onset of chaperone-mediated assembly of the proteasomal ATPases.

两种替代机制调节伴侣介导的蛋白酶体 ATP 酶组装的开始。