Functional and Pharmacological Implications of mGluR Heteromerization

mGluR 异聚化的功能和药理学意义

• 批准号: 8643265
• 负责人: Paul J. Kammermeier
• 金额: $ 29.42万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-03 至 2017-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8643265
• 关键词: Address; Affect; Agonist; American; Autistic Disorder; Binding; Biochemical; Biological Assay; Calcium Channel; Calcium Signaling; Cell fusion; Cells; Clinical; Color; Complementary DNA; Complex; Data; Dimerization; Drug Targeting; Electrophysiology (science); Epilepsy; Family; Fluorescence; Fluorescence Recovery After Photobleaching; G-Protein-Coupled Receptors; GTP-Binding Proteins; Glutamates; Hela Cells; Injection of therapeutic agent; Lead; Ligand Binding; Link; Literature; Mediating; Metabotropic Glutamate Receptors; Modeling; Molecular; Nervous system structure; Neuraxis; Neurons; Pain; Parkinson Disease; Pathologic Processes; Pathology; Pathway interactions; Pharmacology; Phospholipase C; Physiological; Physiological Processes; Play; Property; Protein Family; Public Health; Rattus; Receptor Signaling; Role; Schizophrenia; Signal Transduction; Small Interfering RNA; Spectrum Analysis; Structure of superior cervical ganglion; System; Testing; Therapeutic; Transfection; base; dimer; innovation; interest; knock-down; member; multi-photon; novel; patch clamp; receptor; research study; stoichiometry; therapeutic target; tool

DESCRIPTION (provided by applicant): G protein coupled receptors (GPCRs) are the most frequently targeted protein family in clinical therapeutics. The molecular interactions between GPCRs can have a profound impact on their function and on the effects of drugs that target them. We examined the functional and pharmacological effects of interactions between two glutamate-activated GPCRs called mGluR1 and mGluR5, which are known to form homodimeric complexes (mGluR1-mGluR1 and mGluR5-mGluR5 dimers), are involved in many patho-physiological processes, and have widespread distribution in the central nervous system. Our data suggest that these receptors can interact functionally, and that this interaction alters their sensitivity to selective pharmacological agents that target them. We suggest a novel hypothesis to explain this interaction in which mGluR1 and mGluR5 dimers combine to form tetrameric (or possibly larger) complexes with the ability to trans-activate, such that ligand binding to one receptor may activate G protein through the other. Further, these putative tetrameric receptors seem to respond to some pharmacological agents differently than their homodimeric constituents. To address this hypothesis, we will pursue the following Specific Aims: 1) To characterize the unique pharmacological properties of mGluR1/5 heteromers using the rat superior cervical ganglion (SCG) neuronal expression system, 2) To confirm the pharmacological and signaling properties of mGluR1/5 heteromers by expression in HeLa cells and using a different effectors to assay receptor signaling, 3) To directly assess the ability of fluorescently-tagged mGluR1, mGluR5 and both receptors together to form dimeric, tetrameric, or higher order multimeric receptors using multi-photon Fluorescence Recovery After Photobleaching (FRAP) and Fluorescence Correlation Spectroscopy (FCS), and 4) To verify the physiological relevance of functional mGluR interactions in neurons that natively express both mGluR1 and mGluR5.

描述(申请人提供)：G蛋白偶联受体(GPCRs)是临床治疗中最常见的靶向蛋白家族。GPCRs之间的分子相互作用可以对它们的功能和针对它们的药物的效果产生深远的影响。我们研究了两个被称为mGluR1和mGluR5的谷氨酸激活的GPCRs之间相互作用的功能和药理效应，这两个GPCRs已知形成同源二聚体复合体(mGluR1-mGluR1和mGluR5-mGluR5二聚体)，参与许多病理生理过程，在中枢神经系统中广泛分布。我们的数据表明，这些受体可以在功能上相互作用，这种相互作用改变了它们的 对针对他们的选择性药理药物的敏感性。我们提出了一种新的假说来解释这种相互作用，在这种相互作用中，mGluR1和mGluR5二聚体结合形成具有反式激活能力的四聚体(或更大的)复合体，从而与一个受体结合的配体可以通过另一个受体激活G蛋白。此外，这些假定的四聚体受体似乎对某些药物的反应不同于它们的同源二聚体成分。为了解决这一假设，我们将追求以下具体目标：1)利用大鼠颈上神经节(SCG)神经元表达系统来表征mGluR1/5异构体的独特药理学特性；2)通过在HeLa细胞中的表达并使用不同的效应子来分析受体信号转导来证实mGluR1/5异构体的药理和信号特性；3)利用多光子荧光漂白后恢复(FRAP)和荧光相关光谱(FCS)直接评估荧光标记的mGluR1、mGluR5和这两种受体共同形成二聚体、四聚体或更高阶多聚体受体的能力，4)验证天然表达mGluR1和mGluR5的神经元中功能性mGluR相互作用的生理学相关性。