Mechanism for Regulating Kainate-Type Glutamate Receptor Activity

描述（由申请人提供）：本提案的主要目标是了解调节大脑兴奋性突触传递的机制。神经系统疾病，包括精神发育迟滞、自闭症、癫痫和共济失调，都是由大脑中神经回路的中断引起的。神经回路由通过神经递质在突触处相互通信的神经元组成。大脑中最丰富的兴奋性神经递质是谷氨酸。谷氨酸作用于三类离子型谷氨酸受体，AMPA-、NMDA-和红藻氨酸盐型受体。AMPA受体介导快速突触传递，而NMDA受体调节突触可塑性。然而，红藻氨酸受体的生理作用仍不清楚。我们最近发现了一种新的跨膜蛋白，NETO 2与红藻氨酸受体相互作用，使用公正的蛋白质组学屏幕。在异源细胞和神经元中，NETO 2调节红藻氨酸受体的通道特性，而红藻氨酸受体反过来调节NETO 2运输。然而，有几个未回答的问题，以揭示红藻氨酸受体在大脑中的作用。1. NETO 2/红藻氨酸受体复合物如何组装和运输到细胞表面2。NETO 2和红藻氨酸受体如何相互调节？3. NETO 2/红藻氨酸受体复合物如何介导突触传递？在本研究中，我们将解决这些问题，以揭示红藻氨酸受体/NETO 2复合物在大脑中的功能作用。我们将使用各种转基因小鼠模型来鉴定红藻氨酸受体/NETO 2复合物的蛋白质组装顺序和表面转运机制。我们还将研究NETO 2和红藻氨酸受体的结构和功能分析使用非洲爪蟾卵母细胞作为模型系统。此外，我们还将重构红藻氨酸受体介导的神经元突触传递，通过电生理实验揭示红藻氨酸受体在兴奋性突触传递中的作用。这些研究将为兴奋性突触调节突触传递的机制提供基本的见解，这些机制与大脑中神经回路的作用有关。由于红藻氨酸受体在几种神经系统疾病中的潜在作用，包括自闭症，精神分裂症，癫痫和改变的感觉转导已被提出，这项工作将确定新的药物发现的目标。公共卫生相关性：神经系统疾病，包括精神发育迟滞、自闭症、癫痫和共济失调，都是由大脑中神经回路的中断引起的。这项提议的主要目标是了解调节大脑兴奋性突触传递的机制。这些研究将为兴奋性突触调节突触传递的机制提供基本的见解，这些机制与大脑中神经回路的作用有关。由于红藻氨酸受体在几种神经系统疾病中的潜在作用，包括自闭症，精神分裂症，癫痫和改变的感觉转导已被提出，这项工作将确定新的药物发现的目标。

DESCRIPTION (provided by applicant): The broad goal of this proposal is to understand mechanisms for regulating excitatory synaptic transmission in the brain. Neurological diseases, including mental retardation, autism, epilepsy, and ataxia, are caused by the disruption of neural circuits in the brain. Neural circuits consist of neurons that communicate with each other at synapses through neurotransmitters. The most abundant excitatory neurotransmitter in the brain is glutamate. Glutamate acts on three classes of ionotropic glutamate receptors, AMPA-, NMDA- and kainate-type receptors. AMPA receptors mediate fast synaptic transmission, whereas NMDA receptors modulate synaptic plasticity. However, the physiological roles of kainate receptors remain unclear. We have recently identified a novel transmembrane protein, NETO2 that interacts with the kainate receptor, using an unbiased proteomic screen. In heterologous cells and neurons, NETO2 modulates the channel properties of kainate receptors, and kainate receptors, in turn, modulate NETO2 trafficking. However, there are several unanswered questions to reveal roles of kainate receptors in the brain. 1. How does NETO2/kainate receptor complex assemble and traffic to the cell surface 2. How do NETO2 and kainate receptors modulate each other? 3. How does NETO2/kainate receptor complex mediate the synaptic transmission? In this proposal, we will address these questions to reveal functional roles of kainate receptor/NETO2 complex in the brain. We will identify protein assembling order of kainate receptor/NETO2 complex and mechanisms for surface trafficking using various transgenic mouse model. We will also examine structure and functional analysis of NETO2 and kainate receptors using Xenopus laevis oocyte as a model system. Furthermore, we will reconstitute kainate receptor mediated synaptic transmission in neurons to reveal roles of kainate receptors in excitatory synaptic transmission with electrophysiological experiments. These studies will provide fundamental insights into the mechanisms that regulate synaptic transmission at excitatory synapses regards to roles of neural circuits in the brain. Because potential roles of kainate receptors in several neurological diseases including autism, schizophrenia, epilepsy and altered sensory transduction have been proposed, this work will identify novel targets for drug discovery. PUBLIC HEALTH RELEVANCE: Neurological diseases, including mental retardation, autism, epilepsy, and ataxia, are caused by the disruption of neural circuits in the brain. The broad goal of this proposal is to understand mechanisms for regulating excitatory synaptic transmission in the brain. These studies will provide fundamental insights into the mechanisms that regulate synaptic transmission at excitatory synapses regards to roles of neural circuits in the brain. Because potential roles of kainate receptors in several neurological diseases including autism, schizophrenia, epilepsy and altered sensory transduction have been proposed, this work will identify novel targets for drug discovery.