Allosteric Coupling in Homomeric Cys-loop Receptors

同聚 Cys 环受体中的变构偶联

• 批准号: 7448472
• 负责人: Steven M Sine
• 金额: $ 32.33万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-15 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7448472
• 关键词: Address; Adverse effects; Agonist; Anti-Anxiety Agents; Anticonvulsants; Binding; Binding Sites; Cells; Chimera organism; Coupled; Couples; Coupling; Disease; Drug usage; Epilepsy; Health; Ion Channel; Kinetics; Knowledge; Ligand Binding; Mammalian Cell; Measurement; Mediating; Methods; Molecular; Monitor; Muscle relaxants; Mutation; Myasthenia; Nervous system structure; Neurotransmitter Receptor; Neurotransmitters; Nicotine Dependence; Numbers; Peripheral Nervous System; Pharmaceutical Preparations; Placement; Positioning Attribute; Process; Relative (related person); Signal Transduction; Site-Directed Mutagenesis; Structural Models; Structure; Synapses; Synaptic Transmission; Testing; Therapeutic; Thermodynamics; Time; base; desensitization; insight; mutant; novel; novel strategies; receptor; receptor function; research study; stoichiometry

DESCRIPTION (provided by applicant): Neurotransmitter receptors of the Cys-loop superfamily mediate fast synaptic transmission throughout the central and peripheral nervous systems. Their essential task is to transduce binding of neurotransmitter into opening of an intrinsic ion channel, yet the mechanism by which this transduction is achieved remains unknown. This proposal aims to delineate two fundamental facets of the transduction mechanism in homomeric Cys-loop receptors: (1) the number of agonist binding sites and binding-pore coupling regions required for activation by the agonist and (2) the structural basis for coupling agonist binding to channel gating. The proposed studies take advantage of the relative structural simplicity of homomeric receptors, employ a novel method for generating receptors with prescribed numbers of intact binding sites and coupling regions, and build on our recent demonstration that a network of interdependent loops functionally couples ligand binding and pore domains. The experiments combine expression of chimeric and non-chimeric receptors in mammalian cells, measurements of single channel current amplitudes and dwell times, measurements of ionic currents following rapid application of agonist, site-directed mutagenesis, and structural modeling of receptors. The approaches developed will allow the transduction mechanism to be addressed in all types of Cys-loop receptors, while the overall insights will advance our understanding of how post-synaptic receptors function in health, disease and in the presence of therapeutic drugs. Lay description: Cys-loop receptors relay signals from cell to cell throughout the nervous system, and are implicated in a wide variety of diseases, such as myasthenia, hyperekplexia, epilepsy, and nicotine addiction. They are also targets for drugs used clinically, such as muscle relaxants, anxiolytics, and anticonvulsants. Knowledge of how Cys-loop receptors operate at the molecular level is essential to developing therapeutic strategies and drugs with fewer side effects.

描述（由申请人提供）：Cys-环超家族的神经递质受体介导整个中枢和外周神经系统的快速突触传递。它们的基本任务是将神经递质的结合转化为内在离子通道的开放，然而实现这种转导的机制仍然未知。该提议旨在描述同型半胱氨酸环受体中转导机制的两个基本方面：（1）激动剂激活所需的激动剂结合位点和结合孔偶联区域的数量，以及（2）偶联激动剂结合通道门控的结构基础。拟议的研究利用同源受体的相对结构简单，采用了一种新的方法，用于产生受体与规定数量的完整的结合位点和耦合区域，并建立在我们最近的演示，一个网络的相互依赖的循环功能耦合配体结合和孔域。这些实验结合了哺乳动物细胞中嵌合和非嵌合受体的联合收割机表达、单通道电流幅度和停留时间的测量、激动剂快速应用后离子电流的测量、定点诱变和受体的结构建模。开发的方法将允许在所有类型的Cys环受体中解决转导机制，而整体见解将促进我们对突触后受体在健康，疾病和治疗药物存在下如何发挥作用的理解。 铺设说明：半胱氨酸环受体在整个神经系统中从细胞到细胞传递信号，并且与多种疾病有关，例如肌无力、过度兴奋、癫痫和尼古丁成瘾。它们也是临床上使用的药物的靶点，例如肌肉松弛剂、抗焦虑药和抗惊厥药。了解Cys环受体如何在分子水平上运作对于开发具有较少副作用的治疗策略和药物至关重要。