E3 Ligases and Deubiquitinases in GPCR downregulation

GPCR 下调中的 E3 连接酶和去泛素酶

基本信息

批准号：
7643479
负责人：
SUDHA K SHENOY
金额：
$ 25.89万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-08-01 至 2010-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7643479
关键词：
Adaptor Signaling Protein Address Adrenergic Agents Adrenergic Receptor Agonist Arrestins Asthma Binding Biology Cardiovascular system Cell Surface Receptors Cell surface Cells Characteristics Chronic Cleaved cell Cysteine Protease Degradation Pathway Deubiquitinating Enzyme Deubiquitination Development Down-Regulation Duct (organ) structure Enzymes Family Fluorescence Resonance Energy Transfer G Protein-Coupled Receptor Signaling G-Protein-Coupled Receptors Goals Heart failure Hypertension Isoproterenol Kidney Knowledge Lead Libraries Life Life Cycle Stages Location Lung diseases Lysine Lysosomes Mediating Modification Molecular Post-Translational Protein Processing Process Proteins Recycling Regulation Research Personnel Role Signal Transduction Site Small Interfering RNA Sorting - Cell Movement Specificity Substrate Specificity Time Ubiquitin Ubiquitination V2 Receptors Vasopressin Receptor Vasopressins adapter protein adrenergic antidiuretic attenuation base beta-2 Adrenergic Receptors beta-arrestin cell type design member mutant novel novel therapeutics overexpression prevent programs receptor receptor downregulation receptor internalization research study response trafficking ubiquitin-protein ligase ubiquitin-specific protease

项目摘要

DESCRIPTION (provided by applicant): The beta 1 and beta 2 adrenergic receptors are members of the super-family of G protein-coupled receptors (GPCRs). This receptor super-family comprises some of the most important pharmacological targets for the treatment of cardiovascular (e.g. heart failure, hypertension) and pulmonary diseases (e.g. asthma). A major cause for the observed attenuation of adrenergic response in heart failure and asthma is receptor downregulation, which results from chronic agonist exposure. Recently, ubiquitination of cell-surface receptors has been implicated as an important mechanism for post-endocytic sorting to lysosomes. Ubiquitination is a post-translational modification of proteins orchestrated by a well-defined process involving a cascade of three enzymatic activities. Of these the final step, catalyzed by the enzyme, E3 ubiquitin ligase, determines the specificity of substrate ubiquitination. We have demonstrated that two representative GPCRs, the beta2 adrenergic receptor and the V2 vasopressin receptor and their adaptor protein beta-arrestin become ubiquitinated upon agonist stimulation. Ubiquitination of beta-arrestin is crucial for receptor internalization, whereas ubiquitination of the receptor is essential for the proper sorting and downregulation of the internalized and activated receptors. We hypothesize that ubiquitination and deubiquitination coordinate the trafficking and signaling of GPCRs and involve a specific set of endocytic adapter proteins including beta-arrestins. The specific aims are: 1) to define the molecular mechanisms of receptor ubiquitination leading to receptor downregulation, and 2) to determine the roles of deubiquitinating enzyme(s) in receptor trafficking. Unraveling the molecular mechanisms governing the regulation of GPCRs, especially beta ARs, by ubiquitination could have a great impact on the development of novel therapeutic strategies for cardiovascular and pulmonary diseases.

描述（由申请人提供）：β1和β2肾上腺素能受体是G蛋白偶联受体（GPCR）超家族的成员。该受体超家族包含一些治疗心血管疾病（例如心力衰竭、高血压）和肺部疾病（例如哮喘）的最重要的药理学靶点。心力衰竭和哮喘中观察到的肾上腺素能反应减弱的主要原因是受体下调，这是由长期暴露于激动剂引起的。最近，细胞表面受体的泛素化被认为是溶酶体内吞后分选的重要机制。泛素化是蛋白质的翻译后修饰，由涉及三种酶活性级联的明确过程精心策划。其中最后一步由 E3 泛素连接酶催化，确定底物泛素化的特异性。我们已经证明，两种代表性的 GPCR，β2 肾上腺素能受体和 V2 加压素受体及其接头蛋白 β-抑制蛋白在激动剂刺激后变得泛素化。 β-抑制蛋白的泛素化对于受体内化至关重要，而受体的泛素化对于内化和激活受体的正确分类和下调至关重要。我们假设泛素化和去泛素化协调 GPCR 的运输和信号传导，并涉及一组特定的内吞接头蛋白，包括 β-抑制蛋白。具体目标是：1) 定义受体泛素化导致受体下调的分子机制，2) 确定去泛素化酶在受体运输中的作用。揭示泛素化调节 GPCR（尤其是 β AR）的分子机制可能会对心血管和肺部疾病新型治疗策略的开发产生巨大影响。