Molecular view on binding and unbinding processes between the human β2-adrenergic receptor and its cognate G protein at different stages of the activation cycle

人 β2 肾上腺素受体与其同源 G 蛋白在激活周期不同阶段的结合和解离过程的分子观点

• 批准号: 393547389
• 负责人: Dr. Kristyna Pluhackova
• 金额: --
• 依托单位: Exzellenzcluster EXC 2075 Daten-integrierte Simulationswissenschaft
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/393547389?language=en
• 关键词: Molecular; view; binding; unbinding; processes

The ability of a cell to react to extracellular stimuli is enabled by a complex protein machinery attached to the cell membrane. The core of this machinery consists of transmembrane proteins termed G protein-coupled receptors and their associated G proteins found in the cell interior.This project aims at deciphering the pathways and the underlying free-energy landscapes of the binding and unbinding processes between a G protein and a prominent G-protein coupled receptor, β2-adrenergic receptor, at different stages of the activation cycle and in various membrane environments. The results are expected to provide new important details on the mechanism of signal transmission from the cell exterior to the cell interior and its modulation by membrane composition.Using both atomistic and coarse-grained molecular dynamics simulations we will address the assembly, the structure, and the stability of the signaling complex before and after receptor activation and the stability of the intermediate complex. Simulations will deliver molecular determinants of the G protein-exerted effects on the receptor and an atomistic view on the (un)binding pathways. Moreover, by systematically varying the membrane composition both specific and unspecific effects of different lipids and cholesterol on the interactions between the receptor and the G protein will be elucidated. Complementary multifunctional atomic force microscopy imaging, performed by the host group of Prof. Daniel Müller, will be used to obtain binding force profiles of the G protein to the receptor along the dissociation/association pathways. Moreover, dynamic single-molecule force spectroscopy will be applied to study (de)stabilization effects of the G protein on the receptor at different stages of the activation cycle.This collaborative effort - combining molecular dynamics simulations and atomic force miscroscopy - aims to provide first information at atomistic resolution on the assembly and disassembly of the G protein-coupled receptor/G protein signaling complex and lipid modulation effects thereon.

细胞对细胞外刺激的反应能力是由附着在细胞膜上的复杂蛋白质机制实现的。该机制的核心由称为G蛋白偶联受体的跨膜蛋白及其在细胞内部发现的相关G蛋白组成。本项目旨在解读G蛋白与G蛋白偶联受体（β2-肾上腺素能受体）在激活周期的不同阶段和不同膜环境下结合和解结合过程的途径和潜在的自由能景观。这一结果有望为研究信号从细胞外部传递到细胞内部的机制以及细胞膜组成对信号传递的调节提供新的重要细节。利用原子和粗粒度的分子动力学模拟，我们将讨论受体激活前后信号复合物的组装、结构和稳定性，以及中间复合物的稳定性。模拟将提供G蛋白对受体施加影响的分子决定因素，以及对（非）结合途径的原子观点。此外，通过系统地改变膜组成，将阐明不同脂质和胆固醇对受体与G蛋白相互作用的特异性和非特异性影响。由Daniel m<e:1> ller教授主持的互补多功能原子力显微镜成像将用于获得G蛋白沿解离/结合途径与受体的结合力谱。此外，动态单分子力谱将用于研究G蛋白在激活周期的不同阶段对受体的（去）稳定作用。这项结合分子动力学模拟和原子力显微镜的合作努力，旨在提供G蛋白偶联受体/G蛋白信号复合物的组装和拆卸及其脂质调节作用的原子分辨率的第一手信息。