在GPCRs和G蛋白中,分子间和分子内通信的机制
Francesco Raimondi1, Michele Seeber, Pier G De Benedetti
1Dulbecco Telethon Institute (DTI), and Department of Chemistry, University of Modena and Reggio Emilia, via Campi 183, 41100 Modena, Italy.
Journal of the American Chemical Society
|March 14, 2008
概括
计算实验揭示了血栓糖A2受体 (TXA2R) 和其G蛋白 (Gq) 之间的通信通路. 激素对TXA2R的结合促进了G蛋白激活,这对于罗多普辛类受体信号传递至关重要.
科学领域:
- 分子药理学分子药理学
- 计算生物物理学的计算生物物理.
- 信号传导是指信号的传导方式.
背景情况:
- 关氨酸核酸交换因子 (GEFs) 通过调节G蛋白活性来调节细胞信号传递.
- 血素A2受体 (TXA2R) 是一种G蛋白结合受体 (GPCR),参与各种生理过程.
- 了解受体-G蛋白相互作用是解读细胞通信的关键.
研究的目的:
- 通过计算来研究TXA2R及其同类G蛋白 (Gq) 之间的通信机制.
- 阐明受体-G蛋白复合体中介于分子内和分子间通信的途径.
- 为了确定信号传输中涉及的关键结构图案.
主要方法:
- 运用计算实验来模拟这些相互作用.
- 分析的重点在于TXA2R和与GDP相关的Gq异构三聚合物之间的合.
- 研究了诸如E/DRY动机和Gqalpha C-terminus之类的关键区域.
主要成果:
- 在受体-G蛋白界面,激素结合部位和核酸结合部位之间存在双向通信通路.
- 激素结合增加了E/DRY动机附近的溶剂可访问性,促进了Gqalpha C端透.
- 在E/DRY图案中,氨酸在沟通中扮演着关键的角色.
结论:
- 这项研究提供了TXA2R-Gq信号传输的分子基础的见解.
- 与Gqalpha的α5-螺旋体C端的受体接触对于构造变化和核酸释放至关重要.
- 这些发现与GPCRs的更广泛的罗多普辛家族有关.
相关概念视频
G-protein Coupled Receptors
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.
G-protein Coupled Receptors
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.
Transducer Mechanism: G Protein–Coupled Receptors
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, 7TM, or...
GPCRs are also called heptahelical, 7TM, or...
G Protein-coupled Receptors
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...
G Protein-coupled Receptors
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...
Activation and Inactivation of G Proteins
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 affinity and are together...


