Mutational Analysis of Angiotensin II Receptors

血管紧张素 II 受体的突变分析

• 批准号: 6819267
• 负责人: DANIEL K YEE
• 金额: $ 31.7万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-05-01 至 2006-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6819267
• 关键词: angiotensin II; angiotensin receptor; chimeric proteins; enzyme activity; epitope mapping; mitogen activated protein kinase; protein isoforms; protein structure function; receptor binding; receptor expression

EXCEED THE SPACE PROVIDED. It is well recognized that the peptide hormone angiotensin II (AngII) is importantly involved in the regulation of cardiovascular and body fluid homeostasis. Due to the important physiological, endocrine, and behavioral effects of this pepfide, the receptors that respond to AngII are actively studied as targets for potential therapies against vascular lesions associated with endothelial damage, atherosclerosis, hypertension, and cardiac failure. There are two main families of AngII receptors, referred to as the Type 1 (AT0 and the Type 2 (AT2) subtypes. Cloning of these subtypes have revealed that both receptors conform to the heptahelical structural motif of G-protein coupled receptors. Use of receptor mutagenesis has been an invaluable approach to elucidate the structure/functional relationships of G-protein coupled receptors with respect to ligand binding, receptor activation, and G-protein coupling. For AngII receptors, mutagenesis studies have focused primarily on the AT1 receptor and have led to several proposed computer models of this subtype. Due to the low homology (only 34%) shared between the two subtypes coupled with findings that many of the key AT1 receptor residues are not conserved on AT2 receptors, extrapolating current AT1 receptor models to AT2 receptors has been equivocal. Efforts by this laboratory and others have begun to define important AT2 receptor residues that confer this subtype's binding and functional properties. We have shown some surprising commonalities as well as some dissimilarities between AT1 and AT2 receptors with respect to AngII binding and receptor activation. In the present application, we propose to use receptor mutagenesis to continue defining the structure/function relationships for both AnglI receptor subtypes. Comparing and contrasting the structural data between ATt and AT2 receptors will continue to provide additional insights towards the structural design of the entire AngII receptor family. Specifically, this proposal will address: (i) identifying binding epitopes for AT2-specific ligands, i.e. CGP42112A and PD123319; (ii) locating specific residues in transmembrane domains 3 and 7 that maintain the AT1 receptor's drug-nafve, inactive state; (iii) determining the mechanisms of AT1 receptor activation that drive mitogen activating protein kinase activity; (iv) identifying structural elements that control receptor activation for the ATz receptor subtype; and (v) investigating possible formation of AngII receptor dimers, either homologous or heterologous. PERFORMANCE SITE ========================================Section End===========================================

超出所提供的空间。众所周知，肽激素血管紧张素II（AngII）在心血管和体液稳态的调节中发挥着重要作用。由于这种肽具有重要的生理、内分泌和行为作用，人们正在积极研究对 AngII 做出反应的受体，作为针对与内皮损伤、动脉粥样硬化、高血压和心力衰竭相关的血管病变的潜在疗法的靶标。 AngII 受体有两个主要家族，称为 1 型 (AT0) 和 2 型 (AT2) 亚型。这些亚型的克隆表明，这两种受体均符合 G 蛋白偶联受体的七螺旋结构基序。受体诱变的使用是阐明 G 蛋白偶联受体的结构/功能关系的宝贵方法。 配体结合、受体激活和 G 蛋白偶联。对于 AngII 受体，诱变研究主要集中在 AT1 受体上，并提出了几种该亚型的计算机模型。由于两种亚型之间的同源性较低（仅 34%），并且发现许多关键的 AT1 受体残基在 AT2 受体上并不保守，因此推断出当前的 AT1 受体模型 AT2 受体的作用一直是模棱两可的。该实验室和其他实验室已开始努力定义重要的 AT2 受体残基，这些残基赋予该亚型的结合和功能特性。我们已经展示了 AT1 和 AT2 受体在 AngII 结合和受体激活方面的一些令人惊讶的共性和一些差异。在本申请中，我们建议使用受体诱变来继续定义 AnglI 的结构/功能关系。 受体亚型。比较和对比 ATt 和 AT2 受体之间的结构数据将继续为整个 AngII 受体家族的结构设计提供更多见解。具体来说，该提案将解决：（i）识别 AT2 特异性配体的结合表位，即 CGP42112A 和 PD123319； (ii) 定位跨膜结构域 3 和 7 中的特定残基 维持 AT1 受体的无药物、非活性状态； (iii) 确定驱动有丝分裂原激活蛋白激酶活性的 AT1 受体激活机制； (iv) 鉴定控制 ATz 受体亚型受体激活的结构元件； (v)研究AngII受体二聚体的可能形成，无论是同源的还是异源的。演出现场 =========================================章节结束==============================================