一个无接体GPCR-Gαβγ中间复合物的结构和功能
Maxine Bi1, Xudong Wang2, Jinan Wang3
1Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143.
Research square
|July 9, 2024
概括
研究人员揭示了中间G蛋白结合受体 (GPCR) -G蛋白复合物的结构. 这种中间复合体启动核酸交换,为GPCR信号通路提供了新的见解.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 药理学 药理学是指药理学的学科.
背景情况:
- 了解G蛋白结合受体 (GPCR) 中介复合体对于药物开发至关重要.
- 现有的结构数据主要显示完全激活的GPCR-G蛋白质复合体,使中间状态不明.
研究的目的:
- 为了确定中间GPCR-G蛋白质复合物的结构.
- 调查这种中间复合体在启动信号传输中的功能作用.
主要方法:
- 利用19F定量NMR和分子动力学 (MD) 模拟来绘制结构景观的地图.
- 使用冷电子显微镜 (cryo-EM) 以2.8 Å分辨率确定中间复合物的结构.
- 阻止过渡到完全激活状态以捕获中间体.
主要成果:
- 确定了一个中间GPCR-mini-Gαsβγ复合物的冷-EM结构.
- 提供了直接的证据,即中间复合体驱动了一个速度有限的核酸交换.
- 观察到Gααα螺旋域 (AHD) 的部分开放,由第二个核酸参与,得到MD模拟的支持.
结论:
- 介质复合体在GPCR信号传递中代表了一个独特的功能状态.
- 这种中间复合体可以独立于完全激活,启动核酸交换.
- 这些发现弥合了GPCR信号机制和药物发现方面的关键知识差距.
更多相关视频
07:41A Kinetic Fluorescence-based Ca2+ Mobilization Assay to Identify G Protein-coupled Receptor Agonists, Antagonists, and Allosteric Modulators
Published on: February 20, 2018
8.9K
09:19Strategic Screening and Characterization of the Visual GPCR-mini-G Protein Signaling Complex for Successful Crystallization
Published on: March 16, 2020
7.0K
相关概念视频
Activation and Inactivation of G Proteins
7.0K
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high...
7.0K
G-protein Coupled Receptors
117.9K
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
117.9K
G Protein-coupled Receptors
11.7K
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
11.7K
Transducer Mechanism: G Protein–Coupled Receptors
1.9K
G Protein–Coupled Receptors (GPCRs) are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to various stimuli. GPCRs regulate critical physiological pathways and are excellent drug targets for treating diseases such as diabetes, cancer, obesity, depression, or Alzheimer's. Nearly 35% of approved drugs implement their therapeutic effects by selectively interacting with specific GPCRs.
GPCRs are also called heptahelical,...
GPCRs are also called heptahelical,...
1.9K
GPCR Desensitization
5.9K
G protein-coupled receptor (GPCR) signaling plays a crucial role in cell functioning. GPCR desensitization is an equally essential process. It allows cells to respond to changing environments and regain sensitivity to new stimuli while preventing unnecessary stimulation when no longer needed. Prolonged exposure to stimuli leads to GPCR desensitization. It involves blocking the receptors from binding and activating additional G proteins. This inhibits activation of downstream effectors, thereby...
5.9K
Assembly of Signaling Complexes
5.7K
Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
5.7K
