Structure and dynamics of G protein coupled receptor-G protein complexes

G蛋白偶联受体-G蛋白复合物的结构和动力学

• 批准号: 8635362
• 负责人: Brian K Kobilka
• 金额: $ 56.75万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8635362
• 关键词: AVPR2 gene; Address; Adenylate Cyclase; Adrenergic Receptor; Affinity; Alzheimer' s Disease; Amino Acids; Behavior; Behavior Disorders; Binding; Biochemical; Cardiac; Cardiovascular Diseases; Cell physiology; Cells; Complex; Couples; Coupling; Crystallography; Diabetes Mellitus; Disease; Dissociation; Family; Funding; G Protein-Coupled Receptor Signaling; G-Protein-Coupled Receptors; GTP Binding; GTP-Binding Protein alpha Subunits, Gs; GTP-Binding Proteins; Goals; Guanosine Triphosphate; Guanosine Triphosphate Phosphohydrolases; Heart Rate; Homeostasis; Hormones; Human Genome; Inflammation; Inhibitory G-Protein Gi; Laboratories; Link; Lung diseases; Membrane Proteins; Muscarinic M2 Receptor; Muscarinics; Neurotransmitters; Obesity; Parasympathetic Nervous System; Pathway interactions; Pharmaceutical Preparations; Physiological; Play; Process; Proteins; Regulation; Resolution; Role; Signal Transduction; Signaling Protein; Sodium Chloride; Specificity; Structure; Therapeutic; Time; Vasopressin Receptor; Vasopressins; Water; base; design; drug development; drug discovery; event cycle; flexibility; insight; interest; peptide hormone; protein activation; protein complex; receptor coupling; response

DESCRIPTION (provided by applicant): The goal of this proposal is to determine the structural basis by which G protein-coupled receptors (GPCRs) activate specific G proteins. The majority of hormones and neurotransmitters communicate information to cells via GPCRs, and GPCRs represent the largest group of targets for drug development. Our laboratories have a long-standing interest in elucidating the structure and mechanism of G protein activation by GPCRs. During the previous funding period we succeeded in obtaining the first crystal structure of a GPCR-G protein complex: the beta2 adrenoceptor (?2AR) in complex with Gs, the stimulatory protein for adenylyl cyclase. This structure provides important mechanistic insight into G protein activation, but at the same time raises new questions that will be addressed in this competitive renewal. Specific Aims include: Aim 1. Determine the structural basis of GPCR-G protein coupling specificity. The structure of the ?2AR-Gs complex provided the first high-resolution insights into transmembrane signaling by a GPCR. However, additional GPCR-G protein complexes will be required to understand the structural basis for G protein coupling specificity, and to determine if the mechanistic insights obtained from the ?2AR -Gs structure are generalizable to other GPCR-G protein pairs. We therefore propose to obtain three additional GPCR-G protein complex structures: (1) the vasopressin receptor-Gs complex; (2) the structure of the ?2AR-Gi complex; and (3) the structure of the M2R-Gi complex. Aim 2. Characterize the formation of the ?2AR-Gs complex from the GDP bound Gs heterotrimer. The ?2AR- Gs crystal structure represents a single state in a complex cycle of events. The process of complex formation and dissociation remains poorly understood. These are dynamic process that may not be addressable by crystallography; however, the ?2AR-Gs structure will provide the basis for designing and interpreting biochemical and biophysical studies to characterize the mechanism of complex formation and dissociation. In Aim 2 we will characterize the low affinity interactions between the ?2AR and GDP bound Gs. These interactions may play a role in G protein coupling specificity. Aim 3. Characterize the process of ?2AR -Gs dissociation following GTP binding. The goal of this Aim is to understand how the ?2AR -Gs complex dissociates into active signaling proteins upon binding GTP and to identify persisting interactions between any of the three components: ?2AR, G?s and G??. Aim 4. Characterize the dynamic behavior of the G?s alpha helical domain. The most surprising and unexpected feature of ?2AR-Gs structures is the flexible link between the two domains that make up G?s: the Ras-like GTPase domain and the alpha helical domain (AHD). This subaim will further characterize the interactions between these two domains in the ?2AR-Gs complex as well as in GTP and GDP bound states.

描述（由申请人提供）：该建议的目的是确定G蛋白偶联受体（GPCR）激活特定G蛋白的结构基础。大多数激素和神经递质通过GPCR将信息传达给细胞，而GPCR是最大的药物开发靶标。我们的实验室对阐明GPCR的G蛋白激活的结构和机制具有长期的兴趣。在上一个资金期间，我们成功地获得了GPCR-G蛋白复合物的第一个晶体结构：与GS复合物的beta2肾上腺素受体（？2AR），GS，腺苷酸环化酶的刺激蛋白。该结构为G蛋白激活提供了重要的机械洞察力，但同时提出了将在此竞争更新中解决的新问题。具体目的包括：目标1。确定GPCR-G蛋白偶联特异性的结构基础。 ？2AR-GS复合物的结构为GPCR提供了对跨膜信号传导的第一个高分辨率见解。但是，将需要其他GPCR-G蛋白复合物来了解G蛋白偶联特异性的结构基础，并确定是否从？2AR-GS结构获得的机械见解是否可以推广到其他GPCR-G蛋白对。因此，我们建议获得另外的三个GPCR-G蛋白复合物结构：（1）加压素受体-GS复合物； （2）？2AR-GI复合物的结构； （3）M2R-GI复合物的结构。 AIM 2。表征来自GDP结合GS异三聚体的2AR-GS复合物的形成。 2AR-GS晶体结构在复杂的事件循环中表示单个状态。复杂的形成和解离的过程仍然很少理解。这些是通过晶体学无法解决的动态过程。但是，“ 2AR-GS结构”将为设计和解释生化和生物物理研究以表征复杂形成和解离的机制提供基础。在AIM 2中，我们将表征？2AR和GDP绑定的GS之间的低亲和力相互作用。这些相互作用可能在G蛋白偶联特异性中起作用。 AIM 3。表征GTP结合后？2AR -GS解离的过程。此目的的目的是了解绑定GTP时如何将其分离为活性信号蛋白，并确定三个组件中的任何一个之间的持续相互作用：？2ar，g？s和g ??。 AIM 4。表征G？s alpha螺旋域的动态行为。 ？2AR-GS结构的最令人惊讶和意外的特征是构成G？s的两个域之间的灵活链接：类似Ras的GTPase域和Alpha Helical域（AHD）。该Subaim将进一步表征？2AR-GS复合物以及GTP和GDP结合状态中的这两个域之间的相互作用。