Structural Basis of Signal Instigation Through Metabotropic Glutamate Receptors

通过代谢型谷氨酸受体信号激发的结构基础

• 批准号: 9928579
• 负责人: Georgios Skiniotis
• 金额: $ 8.96万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9928579
• 关键词: Adopted; Agonist; Alpha Particles; Amino Acids; Anxiety; Architecture; Binding; Binding Proteins; Binding Sites; Biochemical; Biological Assay; Cell membrane; Cells; Central Nervous System Diseases; Characteristics; Clams; Cognition; Combat Disorders; Communication; Complement; Complex; Coupled; Coupling; Cryoelectron Microscopy; Crystallization; Cysteine-Rich Domain; Data; Defect; Detergents; Drug Targeting; Electron Spin Resonance Spectroscopy; Environment; Extracellular Domain; Family; Family member; Fragile X Syndrome; Functional disorder; G-Protein-Coupled Receptors; GTP-Binding Proteins; Glutamates; Heterotrimeric GTP-Binding Proteins; Human Genome; Imagery; Investigation; Knowledge; Learning; Length; Ligands; Link; Lipids; Lipoproteins; Measurement; Membrane; Membrane Proteins; Memory; Mental Depression; Metabotropic Glutamate Receptors; Methods; Modeling; Molecular; Molecular Conformation; Mutagenesis; N-terminal; Nerve Degeneration; Nervous System Physiology; Neuraxis; Neurologic; Neurotransmitters; Pain; Parkinson Disease; Pharmacology; Physiological; Population; Protein Conformation; Protein Engineering; Proteins; Receptor Signaling; Resolution; Role; Schizophrenia; Side; Signal Transduction; Structural Models; Structure; Synapses; Synaptic Transmission; Synaptic plasticity; System; Techniques; Technology; Transmembrane Domain; Venus; Work; addiction; autism spectrum disorder; conformational conversion; conformer; design; dimer; drug discovery; experimental study; extracellular; fly; glutamatergic signaling; interest; member; metabotropic glutamate receptor 2; metabotropic glutamate receptor type 1; molecular dynamics; nervous system disorder; neuronal excitability; neuropsychiatry; novel therapeutics; pain perception; particle; positive allosteric modulator; presynaptic; receptor; reconstitution; therapeutic target

Abstract Metabotropic Glutamate receptors (mGluRs) belong to the Family C of G-protein coupled receptors (GPCRs) and critically regulate neuronal excitability, synaptic transmission and plasticity through recognition of the amino acid and excitatory neurotransmitter glutamate. Many disorders of the CNS have been linked to alterations in neuronal excitability via the glutamatergic system. Accordingly, mGluRs have been the subject of an enormous drug discovery effort as they represent major therapeutic targets for treating numerous physiological dysfunctions and for neurodegenerative and neuropsychiatric conditions. Apart from the prototypical seven transmembrane helix (7TM) domain, mGluRs also include a large extracellular `venus fly trap' (VFT) domain that constitutes the glutamate binding site and a cysteine rich domain (CRD) that links the VFT to the 7TM. Binding of glutamate to the extracellular VFT domain triggers a large conformational change in the VFT domains from an open to a closed conformation. This clam-shell like closure of the extracellular domain results in receptor engagement and activation of G-proteins on the intracellular side of the transmembrane domain. Receptor activated G proteins then act to either enhance or repress secondary messenger signaling cascades. Despite intensive efforts, the mechanism of allosteric communication across the cell membrane by the mGluRs remains enigmatic due to the lack of structural information on full- length proteins. Here we propose to apply single-particle cryo-electron microscopy (cryo-EM) visualization in order to characterize the structure of mGluR5 and mGluR2 in activated and inactivated states and also in complex with their cognate G-proteins. The obtained structures will be used for molecular dynamics simulations aiming to unravel the molecular basis for conformational transitions coupled to signal instigation or silencing. Given that mGluRs are important drug targets for several CNS conditions including Parkinson's disease, Fragile X syndrome/autism spectrum disorders, schizophrenia, cognition, addiction, depression, anxiety and pain, the results obtained will have profound biomedical interest and will form the basis for the design of novel therapeutic strategies against neurological disorders.

摘要 代谢型谷氨酸受体（mGluRs）属于G蛋白C家族 偶联受体（GPCRs），并严格调节神经元的兴奋性，突触 传递和可塑性通过识别的氨基酸和兴奋性 神经递质谷氨酸。许多中枢神经系统疾病与 神经元兴奋性的改变通过多巴胺能系统。因此，委员会认为， mGluR已经成为巨大的药物发现努力的主题，因为它们 代表了治疗许多生理性疾病的主要治疗靶点 功能障碍和神经退行性疾病和神经精神疾病。除了 从原型的七跨膜螺旋（7 TM）结构域，mGluRs还 包括一个大的细胞外“venus fly trap”（VFT）结构域， 谷氨酸结合位点和将VFT连接到谷氨酸结合位点的富含半胱氨酸的结构域（CRD）。 7TM。谷氨酸与细胞外VFT结构域的结合引发了大的 VFT结构域从开放到封闭的构象变化 构象细胞外结构域的这种蛤壳状闭合导致 受体的接合和G蛋白的激活的细胞内侧的 跨膜结构域受体激活的G蛋白，然后采取行动， 增强或抑制第二信使信号级联。尽管密集 努力，变构通信的机制，通过细胞膜 由于缺乏完整的结构信息，mGluRs仍然是个谜。 长度蛋白在这里，我们建议应用单粒子低温电子 显微镜（cryo-EM）可视化，以表征 活化和失活状态以及复合物中的mGluR 5和mGluR 2 与其同源的G蛋白。所获得的结构将用于分子 动力学模拟旨在解开构象的分子基础， 与信号激发或沉默相关联的转变。鉴于mGluRs是 是几种CNS疾病的重要药物靶点，包括帕金森病， 脆性X综合征/自闭症谱系障碍、精神分裂症、认知、 成瘾，抑郁，焦虑和痛苦，所获得的结果将有深刻的 生物医学的兴趣，并将形成新的治疗设计的基础 针对神经系统疾病的策略。