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: 9063626
• 负责人: Georgios Skiniotis
• 金额: $ 61.44万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-15 至 2020-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9063626
• 关键词: Adopted; Agonist; 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; Cysteine-Rich Domain; Data; Defect; Detergents; Drug Targeting; Electron Spin Resonance Spectroscopy; Environment; Excitatory Amino Acids; Extracellular Domain; Family; Family member; Fragile X Syndrome; Functional disorder; G-Protein-Coupled Receptors; GTP-Binding Proteins; Glutamates; Health; 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; Perception; Physiological; Population; Protein Conformation; Protein Engineering; Proteins; 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; base; conformational conversion; conformer; design; dimer; drug discovery; extracellular; fly; glutamatergic signaling; interest; meetings; member; metabotropic glutamate receptor 2; metabotropic glutamate receptor type 1; molecular dynamics; nervous system disorder; neuronal excitability; neuropsychiatry; novel therapeutics; particle; positive allosteric modulator; presynaptic; receptor; reconstitution; research study; therapeutic target

 DESCRIPTION (provided by applicant): Metabotropic Glutamate receptors (mGluRs) belong to the Family C of G-protein coupled receptors (GPCRs) and critically regulates 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.

 描述（由申请人提供）：代谢型谷氨酸受体（mGluR）属于G蛋白偶联受体（GPCR）的C家族，通过识别氨基酸和兴奋性神经递质谷氨酸来关键性调节神经元兴奋性、突触传递和可塑性。许多中枢神经系统疾病与神经元兴奋性的改变有关。因此，mGluR已经成为巨大的药物发现努力的主题，因为它们代表了用于治疗许多生理功能障碍以及用于神经变性和神经精神病症的主要治疗靶标。除了原型的七跨膜螺旋（7 TM）结构域之外，mGluR还包括构成谷氨酸结合位点的大的细胞外venus fly trap（VFT）结构域和将VFT连接到7 TM的富含半胱氨酸的结构域（CRD）。谷氨酸与细胞外VFT结构域的结合引发VFT结构域从开放构象到闭合构象的大的构象变化。细胞外结构域的这种蛤壳状闭合导致受体接合和跨膜结构域细胞内侧的G蛋白的活化。受体激活的G蛋白然后起作用以增强或抑制第二信使信号级联。尽管进行了大量的努力，但由于缺乏全长蛋白质的结构信息，mGluR跨细胞膜的变构通讯机制仍然是个谜。在这里，我们建议应用单粒子冷冻电子显微镜（cryo-EM）可视化，以表征mGluR 5和mGluR 2在激活和失活状态下的结构，并与它们的同源G蛋白复合。所获得的结构将用于分子动力学模拟，旨在解开耦合到信号激发或沉默的构象转变的分子基础。鉴于mGluRs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、焦虑和疼痛，所获得的结果将具有深远的生物医学意义，并将形成针对神经系统疾病的新型治疗策略的设计基础。