Molecular Determinants of NMDA-R Trafficking

NMDA-R 贩运的分子决定因素

• 批准号: 7579520
• 负责人: Andres Barria
• 金额: $ 33.76万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-30 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7579520
• 关键词: Affect; Binding; Biochemistry; Biological Assay; Brain; Brain region; Calcium; Chimera organism; Chromosome Pairing; Cognitive deficits; Complement; Dendritic Spines; Development; Electrophysiology (science); Excision; Glutamate Receptor; Goals; Hippocampus (Brain); Image; Lateral; Learning; Life; Measures; Memory; Methodology; Molecular; Molecular Biology; Monitor; Morphology; N-Methylaspartate; Neurons; Numbers; Pathology; Personal Satisfaction; Physiological; Play; Process; Property; Protein Binding; Public Health; Rate; Rattus; Recombinants; Research; Role; Role playing therapy; Scaffolding Protein; Sensory; Shapes; Signal Transduction; Signaling Protein; Slice; Surface; Synapses; Synaptic plasticity; Syndrome; Testing; Thinking; Vertebral column; cell motility; density; experience; fluorescence imaging; innovation; mutant; neuropsychiatry; prevent; protein expression; receptor; receptor function; synaptogenesis; tool; trafficking

DESCRIPTION (provided by applicant): The number, properties, and subunit composition of NMDA-type glutamate receptors (NMDA-Rs) present at a particular synapse must be under careful control in order to regulate calcium influx and different signaling cascades associated with the receptor and its activation. Synapses in many brain regions undergo a switch in the subunit composition of NMDA-Rs from predominantly containing NR2B to predominantly containing NR2A. This switch requires synaptic activity or sensory experience, alters receptor function, and it is thought to affect synaptic plasticity. Recent studies showed that NR2 subunits control the trafficking of NMDA-Rs into synapses with subunit-specific rules. NR2B is incorporated in a constitutive or activity- independent manner, whereas NR2A incorporation requires synaptic activity and is retained intracellularly in the absence of it. We propose to investigate the molecular determinants that control the differential trafficking of NMDA-Rs, the mechanisms involved in the switch of NR2 subunits, and the consequences of altering the composition of synaptic NMDA-Rs. The principal hypothesis is that NR2 subunits control synaptic insertion and stabilization of NMDA-Rs as well as synaptogenesis and spine morphology. These studies will use organotypic hippocampal slices from rat brain and several complementing methodologies, including molecular biology, biochemistry, fluorescence imaging, and electrophysiology. An innovative functional assay will be used to detect incorporation of NMDA-Rs into synapses. Chimeras of NR2 subunits will be used to examine the role played by different structural motifs. The specific aims are: 1) To test the hypothesis that NR2 subunits carry a signal that controls synaptic incorporation and stabilization of NMDA- Rs; 2) To test the hypothesis that NR2A synaptic incorporation requires activity-dependent removal of NR2B-containing receptors and is independent of calcium influx; 3) To test the hypothesis that NR2 subunits control the rate of synaptogenesis and shape the dynamics and morphology of dendritic spines. PUBLIC HEALTH RELEVANCE: Relevance NMDA-type glutamate receptors are a key component of synapses and they are involved in synaptic plasticity, brain development and pathology. The number, properties and subunit composition of the NMDA-Rs present at a particular synapse must be well controlled to regulate processes associated with the receptor and its activation. Our goal is to elucidate the molecular mechanisms that control the number and subunit composition of NMDA-Rs present at synapses. This field of research is poised to be of great significance for the understanding and treatment of multiple neuropsychiatric syndromes associated with cognitive deficits.

描述（由申请人提供）：特定突触处存在的 NMDA 型谷氨酸受体 (NMDA-R) 的数量、性质和亚基组成必须受到仔细控制，以调节钙流入和与受体相关的不同信号级联及其激活。许多大脑区域的突触经历了 NMDA-R 亚基组成的转变，从主要包含 NR2B 到主要包含 NR2A。这种转换需要突触活动或感觉体验，改变受体功能，并且被认为会影响突触可塑性。最近的研究表明，NR2 亚基通过亚基特异性规则控制 NMDA-R 进入突触的运输。 NR2B 以组成型或活性独立的方式掺入，而 NR2A 掺入需要突触活性，并且在没有突触活性的情况下保留在细胞内。我们建议研究控制 NMDA-R 差异运输的分子决定因素、涉及 NR2 亚基转换的机制以及改变突触 NMDA-R 组成的后果。主要假设是 NR2 亚基控制 NMDA-R 的突触插入和稳定以及突触发生和脊柱形态。这些研究将使用大鼠大脑的器官型海马切片和几种补充方法，包括分子生物学、生物化学、荧光成像和电生理学。一种创新的功能测定将用于检测 NMDA-R 与突触的结合。 NR2 亚基的嵌合体将用于检查不同结构基序所起的作用。具体目标是： 1) 检验 NR2 亚基携带控制 NMDA-R 突触掺入和稳定的信号的假设； 2) 检验 NR2A 突触掺入需要活性依赖性去除含 NR2B 受体且与钙流入无关的假设； 3) 检验NR2亚基控制突触发生速率并塑造树突棘的动力学和形态的假设。 公共卫生相关性：相关性 NMDA 型谷氨酸受体是突触的关键组成部分，它们参与突触可塑性、大脑发育和病理学。必须很好地控制特定突触处 NMDA-R 的数量、特性和亚基组成，以调节与受体及其激活相关的过程。我们的目标是阐明控制突触中 NMDA-R 数量和亚基组成的分子机制。这一研究领域对于理解和治疗与认知缺陷相关的多种神经精神综合征具有重要意义。