Physiology of proteasomes in Haloferax volcanii

Haloferax volcanii 蛋白酶体的生理学

• 批准号: 7027109
• 负责人: JULIE A MAUPIN-FURLOW
• 金额: $ 20.96万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7027109
• 关键词: Halobacteriaceae; adenosinetriphosphatase; biological signal transduction; enzyme substrate; microorganism metabolism; mutant; posttranslational modifications; proteasome; protein biosynthesis; protein degradation; protein metabolism; protein purification; proteolysis; proteomics

DESCRIPTION (provided by the applicant): Proteasomes are central to the quality control and regulated turnover of proteins and, thus, are major players in a variety of diseases which impact human health. The haloarchaeon Haloferax volcanii provides an excellent model system for understanding how these multisubunit complexes function as subtypes in the recognition and degradation of proteins in the absence of ubiquitin. This application is based on the identification of proteasome substrates by fluorescent reporter protein analysis and by differential proteomics of proteasome mutant and wild type strains. It is also based on the subunit topology of proteasome subtypes including 20S proteasomes of different alpha subunit composition and hetero- and homo-oligomeric forms of proteasome-activating nucleotidase AAA proteins. Furthermore, it is based on the growth-dependent differential regulation of the mRNA and protein levels of the subunits of these proteasomal subtypes as cells transition from log to stationary phase. This application will test the following hypotheses: (a) Subtypes of AAA ATPases recognize overlapping as well as unique sets of substrates for proteasome-mediated degradation, (b) 20S core particle subtypes of different alpha subunit composition differ in their affinity for these AAA ATPase subtypes, (c) The levels and post-translational modification of the AAA ATPases and alpha proteins are regulated to influence the timing and specificity of protein turnover. Thus, various combinations of AAA ATPase and 20S proteasome subtypes are proposed to form a network for the regulated turnover of proteins in the cell. The proposed combination of genetic and biochemical analysis will identify proteasomal substrates, define how proteasomal subtypes mediate recognition of these substrates, and elucidate the mechanisms involved in regulating the levels and posttranscriptional modification of the components of these proteasome subtypes in H. volcanii.

描述（由申请人提供）：蛋白酶体是蛋白质质量控​​制和调节营业额的核心，因此是影响人类健康的各种疾病中的主要参与者。 HaloArchaeon Haloferax火山岛提供了一个出色的模型系统，用于了解在没有泛素的情况下，这些多重亚基复合物如何在蛋白质识别和降解中充当亚型。该应用基于通过荧光报告蛋白分析以及蛋白酶体突变体和野生型菌株的差异蛋白质组学对蛋白酶体底物的鉴定。它也基于蛋白酶体亚型的亚基拓扑，包括不同α亚基组成的20s蛋白酶体以及蛋白酶体激活核苷酸酶AAA蛋白的异源和同性恋形式。此外，它基于这些蛋白酶体亚型亚型的mRNA和蛋白质水平的生长依赖性差异调节，因为细胞从对数转变为固定相。该应用程序将测试以下假设：（a）AAA ATPases的亚型识别重叠以及蛋白酶体介导的降解的独特底物，（b）20S 20S核心粒子亚型的核心粒子亚型在这些AAA ATPase ATPASE亚型（c）级别（c）级别（c）的AAA ATPASE ATPASE和PORT-clativation and-c）（c）级别（c）aaa anda和capase cons-（c）级别（c）调节蛋白质以影响蛋白质更新的时间和特异性。因此，提出了AAA ATPase和20S蛋白酶体亚型的各种组合形成细胞中蛋白质周转的网络。提出的遗传学和生化分析的组合将鉴定蛋白酶体底物，定义蛋白酶体亚型如何介导这些底物的识别，并阐明调节H. Volcanii中这些蛋白酶体组件的水平和后期修饰水平和后修饰的机制。