Ubiquitin-like Proteins and Proteasomes of Archaea

古细菌的泛素样蛋白和蛋白酶体

基本信息

批准号：
8887421
负责人：
JULIE A MAUPIN-FURLOW
金额：
$ 24.77万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-04-01 至 2019-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8887421
关键词：
26S proteasome ATP phosphohydrolase Active Sites Affinity Archaea Binding Binding Proteins Biochemical Biological Biology Biotechnology Cell division Cell physiology Cells Coiled-Coil Domain Complex DNA Repair Degradation Pathway Development Enzymes Eukaryota Eukaryotic Cell Evolution Florida Genetic Transcription Growth Haloferax volcanii Health High temperature of physical object Homologous Gene Human Human papillomavirus 16 E1 protein Knowledge Laboratories Life Ligase Link Longevity Lysine Malignant Neoplasms Mantle Cell Lymphoma Measures Mediating Metabolism Metalloproteases Modeling Modification Molecular Multiple Myeloma N-terminal Names Nerve Degeneration Oxidative Stress Oxygen Pathogenesis Pathway interactions Patients Peptide Hydrolases Pharmaceutical Preparations Plant Roots Post-Translational Protein Processing Property Proteasome Inhibitor Protein Binding Proteins Proteolysis Public Health Refractory Regulation Relapse Research Resistance Respiration Ribonucleases Role Site Stress Structure Sulfur System Tertiary Protein Structure Thiouridine Transfer RNA Translations Tuberculosis Ubiquitin Ubiquitin Like Proteins Universities Variant Virus Diseases amino group biological adaptation to stress chemotherapy design enzyme activity grasp hypercholesterolemia inhibitor/antagonist insight methionine sulfoxide reductase molybdenum cofactor multicatalytic endopeptidase complex mutant news overexpression oxidation pathogen protein protein interaction public health relevance skills stoichiometry thermal stress

项目摘要

DESCRIPTION (provided by applicant): Ubiquitin-proteasome systems and their homologs are attractive targets for the treatment of some of the most formidable public health challenges of this century including cancer, viral infections, tuberculosis, hypercholesteremia and neurodegeneration. Promising news is that use of proteasome inhibitors, in combination with immunomodulatory drugs, has greatly extended the lifespan of patients with relapsed/refractory multiple myeloma. The fundamental knowledge that enabled the development of these inhibitors was spearheaded by structure-function studies of proteasomes from Archaea. Recently, we discovered that Archaea synthesize ubiquitin-like proteins named SAMPs that are attached by isopeptide bonds to lysine residues of target proteins by an E1-like mechanism (sampylation) that resembles ubiquitylation. SAMPs also mobilize sulfur to form thiolated tRNA and molybdopterin. We hypothesize that SAMPs provide a window for understanding how ubiquitin-like proteins evolved to control cell function including the transient inactivation of enzyme function, targeting of proteins for destruction by proteasomes and coordination of protein modification with sulfur mobilization pathways associated with stress responses. In our research, we demonstrate that polymeric chains of SAMPs are attached near the conserved active site residues of thiouridine synthetase (NcsA), an enzyme linked to oxidative and thermal stress and associated with ubiquitin- like proteins in all domains of life. We also find that many of the lysine residues modified by `sampylation' are near catalytic active sites suggesting a general mechanism of transient enzyme inactivation that may be conserved in eukaryotic cells. SAMPs are also found to target proteins for destruction by mechanisms that appear to require N-terminal degrons and 26S proteasome components. Here we will use the halophilic archaeon Haloferax volcanii as a model to provide insight into how ancient ubiquitin-like modification pathways may control biological activity. In Aim 1, we will define and determine the biological role of the formation of polymeric ubiquitin-like chains of SAMP2 on the thiouridine synthetase (NcsA) associated with maintaining translation fidelity and overcoming thermal stress. In Aim 2, we will provide mechanistic insight into SAMP attachment at or near catalytic active site residues to infer general principles of enzyme regulation that may extend across domains of life. In Aim 3, we will define the interactions of the SAMPs with proteasome-associated AAA ATPases and JAMM/MPN+ domain proteins that may be conserved through evolution. At the conclusion of these studies, we will have expanded our knowledge of ubiquitin-like protein modification and provided an evolutionary perspective on how these attachments may regulate enzyme activity, proteolysis and association with protein partners including proteasomes.

描述（由应用提供）：泛素 - 蛋白酶体系统及其同源物是治疗本世纪一些最正式的公共卫生挑战的有吸引力的目标，包括癌症，病毒感染，结核病，高胆固醇病和神经减退。有前途的消息是，使用蛋白酶体抑制剂与免疫调节药物结合使用，延长了继电器/难治性多发性骨髓瘤患者的寿命。通过对古细菌的蛋白质体的结构 - 功能研究，使能够开发这些抑制剂的基本知识带头。最近，我们发现古细菌合成泛素样蛋白质，称为SAMP，这些蛋白质由异肽键通过类似于泛素化的E1样机制（Sampylation）连接到靶蛋白的赖氨酸保留。 SAMP还动员硫形成硫醇化的tRNA和钼肽。我们假设SAMP为了解泛素样蛋白如何演变为控制细胞功能，包括酶功能的瞬时失活，靶向蛋白质对蛋白质组的破坏以及蛋白质修饰与与应激反应相关的硫途径的蛋白质修饰。在我们的研究中，我们证明了SAMP的聚合物链附着在硫胺合成酶（NCSA）的保守活性位点残基附近，这是一种与氧化和热应激相关的酶，并与生命中所有领域的泛素样蛋白相关。我们还发现，许多赖氨酸保留通过“ sampylation”修饰的赖氨酸靠近催化活性位点，表明在真核细胞中可能保守的瞬时酶失活的一般机制。还发现，通过似乎需要N末端降解和26S蛋白酶体成分的机制靶向蛋白质，以破坏蛋白质。在这里，我们将使用卤素古老的Haloferax火山片作为模型，以洞悉古老的泛素样修饰途径如何控制生物学活性。在AIM 1中，我们将定义并确定与维持翻译保真度并克服热应力相关的硫脲合成酶（NCSA）对SAMP2聚合物泛素样链形成的生物学作用。在AIM 2中，我们将提供有关在催化活性位点残基或附近的SAMP附着的机械洞察力，以推断酶调节的一般原理，这些原理可能会延伸到生命的范围内。在AIM 3中，我们将定义SAMP与蛋白质组相关的AAA ATPases和JAMM/MPN+结构蛋白的相互作用，这些蛋白可能通过进化而成。在这些研究的结论中，我们将扩大对泛素样蛋白质修饰的了解，并就这些附件如何调节酶活性，蛋白水解以及与蛋白质伴侣的关联提供了进化观点。