THE MECHANISM OF A NOVEL FAMILY OF BACTERIAL UBIQUITIN E3 LIGASES IMPORTANT FOR PHAGOSOME REMODELING

对吞噬体重塑重要的新型细菌泛素 E3 连接酶家族的机制

基本信息

批准号：
9751317
负责人：
Yuxin Mao
金额：
$ 30.47万
依托单位：
CORNELL UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-08-01 至 2020-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9751317
关键词：
Address Amino Acids Autophagocytosis Binding Biochemical Biological Biological Process C-terminal Cell Culture Techniques Cell Cycle Cell physiology Cells Charge Collaborations Communicable Diseases Complex Crystallization DNA Repair Data Databases Endoplasmic Reticulum Enzymes Eukaryota Family Genetic Transcription Goals Health Human Immune response Infection Integral Membrane Protein Integration Host Factors Lead Legionella Legionella pneumophila Ligase Ligation Light Lipids Malignant Neoplasms Mammalian Cell Membrane Methods Molecular N-terminal Names Neurodegenerative Disorders Pathogenesis Pathway interactions Pattern Phagosomes Physiological Play Post-Translational Protein Processing Prokaryotic Cells Proteins Reaction Regulation Research Ring Finger Domain Role Signal Transduction Stable Isotope Labeling Structure Surface System Triad Acrylic Resin Ubiquitin Ubiquitin family Ubiquitin-Activating Enzymes Ubiquitination Universities Vacuole Vesicle base combat human disease in vitro activity interdisciplinary approach kinectin member novel paralogous gene pathogen pathogenic bacteria phosphatidylinositol 4-phosphate protein function recruit tool trafficking ubiquitin ligase ubiquitin-protein ligase

项目摘要

PROJECT SUMMARY/ABSTRACT Post-translational modification by ubiquitin is an essential mechanism to alter protein function in eukaryotes. Ubiquitin, a 76 amino acid protein, is attached to specific proteins via a cascade of ubiquitin activating enzyme E1, conjugating enzyme E2, and ubiquitin ligase E3. Ubiquitination plays an essential role in a broad aspect of cellular processes, including transcription, DNA repair, signal transduction, autophagy, cell cycle, immune response, and membrane trafficking. Aberration in the ubiquitination system lead to a number of human diseases, such as neurodegenerative diseases and cancers. Remarkably, although ubiquitin is absent in prokaryotes, Bacterial pathogen encoded E3 ubiquitin Ligase (BELs) are found to be delivered into eukaryotic host cells to manipulate the host ubiquitin system for successful infection. We recently discovered a novel family of BELs, named SidC, from the intracellular bacterial pathogen Legionella pneumophila. SidC have no sequence and structure resemblance to any known eukaryotic RING-type or HECT-like ubiquitin ligases. Our preliminary data raised intriguing questions such as what is the unique molecular mechanism of this novel family of ubiquitin E3 ligases given their apparent disparities to canonic HECT or RING-finger E3 ligases at both primary and tertiary structure levels? What are the specific substrates of SidC? And how the ubiquitination of these host potential host factors play a role in membrane trafficking regulation? The overarching goal of this proposal is to elucidate the molecular mechanism of this distinct family of ubiquitin ligases and their role in exploiting host membrane tracking. Specifically, we will pursuing the following aims: Aim 1: To delineate the molecular mechanism of ubiquitin ligation by SidC/SdcA. Aim 2: To elucidate the activity regulation of SidC/SdcA. Aim 3: To characterize the role of SidC/SdcA in host membrane trafficking and to identify their specific substrates. We expect the successful implementation of this proposal will make significant contributions to the understanding of both the molecular mechanisms of the enzymatic cascade of ubiquitination and the role of host ubiquitin pathway in the pathogenesis of bacterial pathogens.

项目概要/摘要泛素翻译后修饰是改变蛋白质功能的重要机制真核生物。泛素是一种由 76 个氨基酸组成的蛋白质，通过泛素级联连接到特定蛋白质上活化酶E1、结合酶E2和泛素连接酶E3。泛素化起着至关重要的作用在细胞过程的广泛方面发挥作用，包括转录、DNA 修复、信号转导、自噬、细胞周期、免疫反应和膜运输。泛素化的畸变系统导致许多人类疾病，例如神经退行性疾病和癌症。值得注意的是，虽然原核生物中不存在泛素，但细菌病原体编码 E3 泛素连接酶 (BEL)被发现被递送到真核宿主细胞中以操纵宿主泛素系统感染成功。我们最近从细胞内发现了一个新的 BEL 家族，名为 SidC。细菌病原体嗜肺军团菌。 SidC 与任何序列和结构都没有相似之处已知的真核RING型或HECT样泛素连接酶。我们的初步数据令人感兴趣诸如这种新型泛素 E3 连接酶家族的独特分子机制是什么等问题鉴于它们在一级和三级连接酶方面与经典 HECT 或环指 E3 连接酶存在明显差异结构层次？ SidC的具体底物有哪些？以及这些宿主如何泛素化潜在的宿主因素在膜运输调节中发挥作用？本提案的总体目标目的是阐明这一独特的泛素连接酶家族的分子机制及其在利用泛素连接酶中的作用宿主膜追踪。具体来说，我们将追求以下目标：目标 1：划定 SidC/SdcA 泛素连接的分子机制。目标 2：阐明 SidC/SdcA。目标 3：表征 SidC/SdcA 在宿主膜运输中的作用并确定他们的特定底物。我们预计该提案的成功实施将产生重大影响对理解酶级联的分子机制的贡献泛素化和宿主泛素途径在细菌病原体发病机制中的作用。