The Ubiquitin Proteasome System in ER Quality Control

ER 质量控制中的泛素蛋白酶体系统

• 批准号: 7887688
• 负责人: RON R KOPITO
• 金额: $ 50.74万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7887688
• 关键词: Achievement; Address; Biochemical; Biological; Cells; Commit; Complex; Degradation Pathway; Endoplasmic Reticulum; Funding; GRP94; Gene Silencing; Genes; Goals; Health; Hereditary Disease; Human; Informatics; Integral Membrane Protein; Lectin; Mammalian Cell; Mammals; Maps; Mediating; Membrane; Methodology; Mining; Molecular; Molecular Chaperones; Mutation; Pathway interactions; Polysaccharides; Process; Proteins; Proteome; Proteomics; Quality Control; Role; System; Ubiquitin; base; functional genomics; multicatalytic endopeptidase complex; new technology; protein folding; public health relevance; tool

DESCRIPTION (provided by applicant): The long-term goal of this project is to elucidate the mechanisms by which proteins in the secretory pathway are recognized and destroyed by the ubiquitin-proteasome system (UPS) in a process known as endoplasmic reticulum-associated degradation (ERAD). Substrates committed to this fate are diverse, and include secreted and integral membrane proteins that are unable to fold correctly as a consequence of mutation or inefficient assembly into oligomeric complexes. During the current funding period we have made exceptional progress in achieving our primary aims of establishing a robust and versatile functional genomics platform to map functional substrate-specific sub-networks within the mammalian ERAD system, and have exceeded these aims in developing powerful proteomic tools that have enabled us to compile a preliminary map of the mammalian ERAD interactome. The present application proposes to expand these achievements with the goal of defining the role of chaperones and glycans in luminal ER quality control surveillance and to develop a comprehensive understanding of the composition and functional organization of the ERAD system in mammals. These goals are defined three specific aims. The first specific aim will employ established biochemical, cell biological and biophysical methodology to define the mechanisms by which substrates are committed to ERAD pathway and the role of the molecular chaperone, GRP94, in this process. The second specific aim will conduct a large-scale comprehensive functional genomic screen of the entire UPS in the degradation of a set of topologically diverse ERAD substrates and will validate these components using a battery of informatic and biochemical tools. The third specific aim is to construct a comprehensive map of the mammalian ERAD network by combining in-depth mining of the ERAD proteome with gene silencing to identify network topology, and to overlay this map on the substrate-specific functional network generated in Aim 2. These studies are focused on elucidating the molecular mechanisms by which folding or assembly-defective proteins are destroyed by mammalian cells, and therefore, have direct bearing on human health. PUBLIC HEALTH RELEVANCE: The proposed studies will investigate the process by which misfolded or damaged proteins in the secretory pathway are identified and destroyed. Since mutations which influence protein folding underlie most genetic diseases, understanding the cellular mechanisms that defend against such mutations is critical to our understanding of the molecular basis of genetic disease.

描述（由申请人提供）：该项目的长期目标是阐明分泌途径中的蛋白质在称为内质网相关降解（ERAD）的过程中被泛素蛋白酶体系统（UPS）识别和破坏的机制。导致这种命运的底物是多种多样的，包括分泌型膜蛋白和整合膜蛋白，这些蛋白由于突变或低效组装成寡聚复合物而无法正确折叠。在当前的资助期间，我们在实现我们的主要目标方面取得了非凡的进展，即建立一个强大且多功能的功能基因组学平台，以绘制哺乳动物 ERAD 系统内的功能底物特异性子网络，并且在开发强大的蛋白质组学工具方面超越了这些目标，使我们能够编制哺乳动物 ERAD 相互作用组的初步图谱。本申请提出扩大这些成就，目标是确定伴侣和聚糖在管腔 ER 质量控制监测中的作用，并全面了解哺乳动物 ERAD 系统的组成和功能组织。这些目标定义了三个具体目标。第一个具体目标将采用已建立的生物化学、细胞生物学和生物物理方法来定义底物参与 ERAD 途径的机制以及分子伴侣 GRP94 在此过程中的作用。第二个具体目标是对整个 UPS 在一组拓扑多样的 ERAD 底物的降解过程中进行大规模综合功能基因组筛选，并使用一系列信息学和生化工具验证这些组件。第三个具体目标是通过对 ERAD 蛋白质组的深入挖掘与基因沉默相结合来识别网络拓扑，构建哺乳动物 ERAD 网络的综合图谱，并将该图谱叠加到目标 2 中生成的底物特异性功能网络上。这些研究重点是阐明哺乳动物细胞破坏折叠或组装缺陷蛋白的分子机制，因此具有直接意义。 对人类健康。 公共健康相关性：拟议的研究将调查分泌途径中错误折叠或受损蛋白质被识别和破坏的过程。由于影响蛋白质折叠的突变是大多数遗传病的基础，因此了解防御此类突变的细胞机制对于我们了解遗传病的分子基础至关重要。