Regulation of G protein-coupled receptor signaling and trafficking

G 蛋白偶联受体信号传导和运输的调节

• 批准号: 9978885
• 负责人: Jeffrey L Benovic
• 金额: $ 50.7万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9978885
• 关键词: Address; Agonist; Arrestins; Binding; Biochemical; Cells; Complex; Development; Disease; Endocytosis; Environment; G Protein-Coupled Receptor Signaling; G protein coupled receptor kinase; G-Protein-Coupled Receptors; GRK5 gene; GTP-Binding Protein alpha Subunits, Gs; GTP-Binding Proteins; Heterotrimeric GTP-Binding Proteins; Hot Spot; Laboratories; Ligands; Mediating; Molecular Conformation; Molecular Structure; Molecular and Cellular Biology; Pharmaceutical Preparations; Phosphotransferases; Play; Process; Regulation; Research; Role; Signal Transduction; Structure; Therapeutic; Time; X-Ray Crystallography; beta-2 Adrenergic Receptors; beta-arrestin; biophysical analysis; desensitization; insight; receptor; receptor function; residence; trafficking

G protein-coupled receptors (GPCRs) play an essential role in coordinating the ability of cells to rapidly respond to their environment. Agonist binding to a GPCR promotes initial activation of heterotrimeric G proteins, which mediates downstream signaling. Agonist-occupied GPCRs then interact with GPCR kinases (GRKs), which specifically phosphorylate the receptor, and arrestins, which bind to GRK-phosphorylated receptors and function in GPCR desensitization, endocytosis, and signaling. A central question that drives current GPCR research involves understanding the dynamics and structures of GPCR interactions with G proteins, GRKs and arrestins. My laboratory is currently using a variety of strategies including X-ray crystallography, biochemical and biophysical analysis, and molecular and cellular biology to better understand the dynamics of GPCR regulation by GRKs and arrestins and the potential role of these processes in disease. In this application, we propose to address four questions that are central to understanding the mechanisms involved in GRK and arrestin regulation of GPCR signaling and trafficking. Can we obtain structural and dynamic insight on a GPCR/GRK complex? While we currently know little about the critical regions that mediate GRK interaction with GPCRs or how this interaction ultimately regulates GRK activation, our preliminary studies reveal three binding “hot spots” between the β2-adrenergic receptor (β2AR) and GRK5 and suggest large conformational changes in GRK5 upon binding to the receptor. How does β-arrestin interact with the β2-adrenergic receptor and β2-adaptin? β-arrestins play a central role in regulating GPCR signaling and trafficking so further understanding these interactions has important implications. Moreover, structural differences in the receptor when bound to its major downstream targets should provide insight on candidate regions to target in order to selectively enhance or disrupt specific interactions. Do α-arrestins play a broad role in regulating GPCR trafficking and signaling? We have found that the α-arrestin ARRDC3 functions as a switch to modulate the endosomal residence time and subsequent intracellular signaling of the β2AR. We will perform structure/function analysis of ARRDC3 interaction with the β2AR and assess whether ARRDCs have a broad role in regulating GPCR function. What is the molecular and structural basis of biased agonism? While it is evident that biased signaling through a number of GPCRs may ultimately prove to be of significant therapeutic value, literally nothing is known about the structural and mechanistic basis by which ligands can bias GPCR signaling. Overall, a more detailed understanding into these questions has tremendous implications for the development of more effective drugs to treat a wide variety of diseases.

G蛋白偶联受体（GPCR）在协调细胞快速反应的能力方面发挥着重要作用。 与 GPCR 结合的激动剂可促进异源三聚体 G 的初始激活。 蛋白，介导激动剂占据的 GPCR，然后与 GPCR 激酶相互作用。 （GRK），特异性磷酸化受体，以及抑制蛋白，结合 GRK 磷酸化 GPCR 脱敏、内吞作用和信号传导中的受体和功能是驱动的核心问题。 当前的 GPCR 研究涉及了解 GPCR 与 G 相互作用的动力学和结构 我的实验室目前正在使用多种策略，包括 X 射线。 晶体学、生物化学和生物物理分析以及分子和细胞生物学，以更好地了解 GRK 和抑制蛋白对 GPCR 调节的动态以及这些过程在疾病中的潜在作用。 在此应用中，我们建议解决四个对于理解机制至关重要的问题 参与 GPCR 信号传导和运输的 GRK 和抑制蛋白调节。 虽然我们目前对 GPCR/GRK 复合物的关键区域知之甚少？ 介导 GRK 与 GPCR 的相互作用，或者这种相互作用最终如何调节 GRK 激活，我们的研究 初步研究揭示了 β2 肾上腺素受体 (β2AR) 和 GRK5 之间的三个结合“热点” 表明 GRK5 在与受体结合后发生巨大的构象变化。β-arrestin 如何与受体相互作用。 β2-肾上腺素能受体和 β2-适应素在调节 GPCR 信号传导和 因此，进一步了解这些相互作用具有重要意义。 受体与其主要下游靶标结合时的差异应有助于了解候选药物 α-抑制蛋白是否发挥广泛的作用？ 我们发现 α-arrestin ARRDC3 具有调节 GPCR 运输和信号传导的作用？ 我们将开关调节 β2AR 的内体停留时间和随后的细胞内信号传导。 对 ARRDC3 与 β2AR 相互作用进行结构/功能分析，并评估 ARRDC 是否具有 偏向激动的分子和结构基础是什么？ 很明显，通过许多 GPCR 发出的偏向信号最终可能被证明是重要的 治疗价值，实际上对于配体可以发挥作用的结构和机制基础一无所知 总体而言，更详细地了解这些问题具有巨大的意义。 对开发更有效的药物来治疗多种疾病的影响。