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-Loop超家族的神经递质受体介导整个中央和周围神经系统的快速突触传播。他们的必不可少的任务是将神经递质的结合转换为固有离子通道的打开，但是实现这种转导的机制仍然未知。该提案旨在描述同源性CYS-LOOP受体转导机制的两个基本相：（1）激动剂结合位点的数量和激动剂激活所需的结合孔耦合区的数量以及（2）耦合型激动剂与通道基督的结构基础。提出的研究利用了同源受体的相对结构简单性，采用了一种新方法来生成具有规定的完整结合位点和耦合区域数量的受体，并建立在我们最近的证明基础上，即相互依存的环路网络功能偶联的网络在功能上耦合了配体结合和孔子结构域。该实验结合了在哺乳动物细胞中的嵌合和非晶体受体的表达，单信道电流振幅和停留时间的测量，快速应用激动剂，位置定向诱变后离子电流的测量以及受体的结构建模。所开发的方法将允许在所有类型的Cys-loop受体中解决转导机制，而总体见解将促进我们对突触后受体如何在健康，疾病和存在治疗药物的情况下发挥作用的理解。 室外描述：整个神经系统中从细胞到细胞的Cys-Loop受体中继信号，并与多种疾病有关，例如肌无局，杂菌，症状，癫痫和尼古丁成瘾。它们也是临床上使用的药物的靶标，例如肌肉松弛剂，抗焦虑药和抗惊厥药。了解CYS环受体在分子水平上的运作方式对于开发副作用较少的治疗策略和药物至关重要。