STRUCTURE & FUNCTION RELATIONSHIP: PROSTANOID RECEPTORS

结构

• 批准号: 6986789
• 负责人: KE-HE RUAN
• 金额: $ 35.45万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-12-01 至 2008-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6986789
• 关键词: G protein; biological signal transduction; cardiovascular disorder; cardiovascular function; cell surface receptors; circular dichroism; computer simulation; hemostasis; inflammation; magnetic resonance imaging; myocardial infarction; prostacyclins; prostaglandin E; prostaglandin F; prostaglandin receptor; prostaglandins; protein structure function; receptor coupling; site directed mutagenesis; stroke; synthetic peptide; thrombosis; thromboxanes

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand how prostanoid receptors mediate human physiopathological vascular and hemodynamic processes, including hemostasis, thrombosis, and inflammation. Prostanoids, including thromboxane A2 (TXA2), prostacyclin 12 (PGI2) and prostaglandin D2 (PGD2), E2 (PGE2) and F2 (PGF2) are synthesized by vascular smooth muscle, endothelium, and other tissues. TXA2 is a potent stimulator of platelet aggregation and a smooth muscle constrictor. PGI2 actions are essentially opposite to those of TXA2. PGE2 plays diverse/opposite functions as a vasodilator or vasoconstrictor based on the mediations of the subtype receptors. TXA2 and PGI2 are also mediated by their receptors. All the receptors belong to the G protein-coupled receptor family, with seven transmembrane domains, and are coupled to different signaling. The structure and function relationships of the TXA2 receptor (TP), the PGI2 receptor (IP) and four subtype PGE2 receptors (EP) are poorly defined, with little structural information on how the prostanoids recognize their receptors and signaling through G proteins specifically. The diverse receptor-mediated actions of TXA2, PGI2, and PGE2 have led us to hypothesize that the receptors have distinct 3D structures in their extracellular ligand recognition sites, and in their intracellular G protein-coupled sites. Recently, we have partially characterized the ligand-binding pockets in the extracellular domains, and parts of the intracellular G protein coupling domains of the TP and IP receptors. Further characterization of the specific ligand recognition and G protein coupling sites of the TP, IP, and a typical EP receptor should reveal their differences. The following specific aims will use recombinant receptor mutants, synthetic peptides, circular dichroism and 2D nuclear magnetic resonance spectroscopy to: 1. Identify the segments and key residues comprising the TP receptor agonist recognition pocket for comparison with the antagonist recognition pocket; 2. Determine the solution conformation of the extracellular domains of the IP receptor and define the segments and key residues making up the ligand recognition pocket; 3. Determine the solution conformation of the extracellular domains in the human EP3 receptor, and identify the residues making up its specific ligand recognition pocket for comparison with those of the TP and IP receptors; 4. Determine the solution conformation of segments comprising the intracellular domains.

描述（由申请人提供）：该项目的长期目标是了解前列腺素受体如何介导人类生理病理学血管和血液动力学过程，包括止血，血栓形成和炎症。前列腺素化物，包括血栓烷A2（TXA2），前列环蛋白12（PGI2）和前列腺素D2（PGD2），E2（PGE2）和F2（PGF2）是由血管平滑肌，Endellium和其他组织合成的。 TXA2是血小板聚集和平滑肌收缩器的有效刺激剂。 PGI2动作与TXA2的作用基本相反。 PGE2基于亚型受体的介导，作为血管扩张剂或血管收缩剂的多样性/相对功能。 TXA2和PGI2也由其受体介导。所有受体均属于G蛋白偶联受体家族，具有七个跨膜结构域，并耦合到不同的信号传导。 TXA2受体（TP），PGI2受体（IP）和四个亚型PGE2受体（EP）的结构和功能关系的定义很差，几乎没有关于前列腺素如何通过G蛋白特别明确地识别其受体和信号传导的结构信息。 TXA2，PGI2和PGE2的不同受体介导的作用导致我们假设受体在其细胞外配体识别位点以及其细胞内G蛋白偶联的位点具有不同的3D结构。最近，我们部分表征了细胞外结构域中的配体结合袋，以及TP和IP受体的细胞内G蛋白偶联结构域的一部分。 TP，IP和典型EP受体的特定配体识别和G蛋白偶联位点的进一步表征应揭示其差异。以下特定目的将使用重组受体突变体，合成肽，圆二色性和2D核磁共振光谱谱图：1。确定构成TP受体激动剂识别袋的片段和关键残基，以与拮抗剂识别袋进行比较； 2。确定IP受体的细胞外域的溶液构象，并定义构成配体识别口袋的片段和关键残基； 3。确定人EP3受体中细胞外域的溶液构象，并确定构成其特定配体识别袋的残基，以与TP和IP受体的残基进行比较； 4。确定包含细胞内结构域的片段的溶液构象。