Molecular Regulation of Metabotropic Glutamate Receptors in Striatal Neurons

纹状体神经元代谢型谷氨酸受体的分子调控

• 批准号: 8247797
• 负责人: QIANG WANG
• 金额: $ 37.13万
• 依托单位: UNIVERSITY OF MISSOURI KANSAS CITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-12-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8247797
• 关键词: Acute; Address; Affinity; Amino Acids; Amphetamines; Antibodies; Area; Autoradiography; Basal Ganglia; Behavior; Behavior Control; Behavioral; Binding; Biochemical; Brain; C-terminal; Cells; Chronic; Cognition; Corpus striatum structure; Development; Disease model; Drug Addiction; Emotions; Feedback; Glutamate Receptor; Glutamates; Homer protein; Immunoblotting; In Vitro; Injection of therapeutic agent; Kinetics; Life; Link; Liquid Chromatography; Mediating; Mental disorders; Metabotropic Glutamate Receptors; Modeling; Molecular; Motivation; Motor Activity; N-Methyl-D-Aspartate Receptors; Neuraxis; Neurons; Peptides; Pharmacotherapy; Phosphorylation; Phosphoserine; Phosphothreonine; Phosphotransferases; Pilot Projects; Plastics; Post-Translational Regulation; Property; Protein Kinase; Proteomics; RNA Splicing; Reaction; Regulation; Research Project Grants; Rewards; Role; Series; Serine; Signal Transduction; Site; Small Interfering RNA; Substance Addiction; Synapses; Tail; Testing; Variant; addiction; base; behavioral sensitization; calmodulin-dependent protein kinase II; clinically relevant; design; drug of abuse; in vivo; innovation; insight; interdisciplinary approach; mutant; nano; neurobehavioral; novel; protein protein interaction; psychostimulant; public health relevance; receptor; receptor function; research study; scaffold; stem; tandem mass spectrometry; trafficking; transmission process

DESCRIPTION (provided by applicant): Protein phosphorylation is an important mechanism for post-translational regulation of glutamate receptors. Through phosphorylating a specific amino acid in the intracellular domain, protein kinases regulate anchoring, trafficking, and signaling of a given glutamate receptor. Group I metabotropic glutamate receptors (mGluR1/5) are densely expressed in the striatum, a brain area involved in addictive properties of psychostimlants. The long-form mGluR1/5 splice variants (1a, 5a, and 5b) have a large intracellular C-terminal tail, which provides a basis for direct protein-protein interactions and phosphorylation. In our recent studies, we found that Ca2+/calmodulin-dependent protein kinase II (CaMKII) binds directly to the proximal region of mGluR5a C-terminus. This binding converts mGluR5a into a biochemical substrate for phosphorylation likely at a selective serine site. These findings raise innovative questions as to if CaMKII regulates mGluR1/5 via a direct protein-protein interaction and phosphorylation and if this regulation has a high clinical relevance in a disease model. In this continuation proposal, a series of coherent experiments from molecule to behavior was proposed to confirm the direct binding of CaMKII to mGluR1/5 in vitro and to establish that native CaMKII and mGluR1/5 interact with each other in striatal neurons in vivo. We will characterize if and how Ca2+ regulates the interaction between CaMKII and mGluR1/5 in vitro and in vivo. We will then investigate whether Ca2+-regulated CaMKII-mGluR1/5 interactions regulate 1) signaling efficacy of mGluR1/5, 2) trafficking of the receptors, and 3) interactions of mGluR1/5 with key scaffold Homer proteins, in striatal neurons or heterologous cells. Finally, we will carry out neurobehavioral experiments to define the role of CaMKII-mGluR1/5 interactions in the addictive action of the psychostimulant amphetamine. Our results will provide evidence and insights for a new synaptic model of kinase-regulated mGluRs and for its linkage to a mental illness (substance addiction). They will also ultimately contribute to the development of novel pharmacotherapies, by targeting mGluRs and CaMKII, for treating various mental illnesses, including addiction. PUBLIC HEALTH RELEVANCE: This research project is aimed to elucidate molecular mechanisms underlying the regulation of metabotropic glutamate receptors and roles of the receptor in drugs of abuse. The information obtained through this project is valuable for the development of new pharmacotherapies for mental illnesses stemming from dysfunctional glutamatergic transmission in the central nervous system.

描述（由申请人提供）：蛋白磷酸化是谷氨酸受体翻译后调节的重要机制。通过磷酸化细胞内结构域中的特定氨基酸，蛋白激酶调节给定谷氨酸受体的锚定、运输和信号传导。I组代谢型谷氨酸受体（mGluR1/5）密集表达于纹状体，纹状体是涉及精神刺激剂成瘾性质的脑区。长型mGluR1/5剪接变体（1a、5a和5b）具有大的细胞内C末端尾，这为直接的蛋白质-蛋白质相互作用和磷酸化提供了基础。在我们最近的研究中，我们发现Ca~（2+）/钙调素依赖性蛋白激酶II（CaMKII）直接结合到mGluR5a C-末端的近端区域。这种结合将mGluR5a转化为可能在选择性丝氨酸位点磷酸化的生化底物。这些发现提出了创新的问题，如CaMKII是否通过直接的蛋白质-蛋白质相互作用和磷酸化调节mGluR1/5，以及这种调节在疾病模型中是否具有高度的临床相关性。在这个延续的提议中，提出了一系列从分子到行为的连贯实验，以证实体外CaMK II与mGluR1/5的直接结合，并建立体内纹状体神经元中天然CaMK II和mGluR1/5相互作用。我们将表征钙离子是否以及如何在体外和体内调节CaMKII和mGluR1/5之间的相互作用。然后，我们将研究在纹状体神经元或异源细胞中，Ca 2+调节的CaMKII-mGluR1/5相互作用是否调节1）mGluR1/5的信号传导功效，2）受体的运输，以及3）mGluR1/5与关键支架Homer蛋白的相互作用。最后，我们将进行神经行为实验，以确定CaMKII-mGluR1/5相互作用在精神兴奋剂安非他明成瘾作用中的作用。我们的研究结果将为激酶调节mGluRs的新突触模型及其与精神疾病（物质成瘾）的联系提供证据和见解。他们还将通过靶向mGluRs和CaMKII，最终有助于开发新的药物疗法，用于治疗各种精神疾病，包括成瘾。 公共卫生相关性：本研究旨在阐明代谢型谷氨酸受体调控的分子机制及其在药物滥用中的作用。通过该项目获得的信息对于开发用于治疗中枢神经系统中功能障碍性神经递质传递引起的精神疾病的新药物疗法是有价值的。