Dig and CASK at the mammalian neuromuscular junction

在哺乳动物神经肌肉接头处挖掘和桶

• 批准号: 6845517
• 负责人: Jill A Rafael-Fortney
• 金额: $ 4.01万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6845517
• 关键词: NMDA receptors; genetically modified animals; laboratory mouse; neuromuscular junction; neurotransmitter receptor; protein binding; protein localization; protein protein interaction; protein structure function; sodium channel; striated muscles; transcription factor

DESCRIPTION (provided by applicant): The clustering of neurotransmitter receptors at the post-synaptic membrane of synapses is essential for efficient transmission of a signal from a neuron to its target. At the cholinergic mammalian neuromuscular junction (NMJ) the mechanisms of acetylcholine receptor clustering and the physiology of these neurotransmitter receptors have been well studied. However, little is known about the roles of other receptors and channels, including NMDA glutamate and ErbB4 receptors, and sodium channels that are also localized to this post-synaptic membrane. A family of proteins containing a PDZ protein motif localizes channels and receptors at glutamatergic Drosophila NMJ and mammalian central nervous system synapses and are thought to play a fundamental role in the organization, structure, and function of these synapses. We have recently shown the localization of several of these PDZ domain proteins at the post-synaptic membrane of the mammalian NMJ. Two of these PDZ domain proteins, Dlg and CASK, represent excellent candidates for interacting with the NMDA and ErbB4 receptors and sodium channels at the NMJ post-synaptic membrane. The aims of the current application are to determine the proteins with which Dlg and CASK interact in skeletal muscle, whether these two proteins are responsible for localizing channels and receptors at the NMJ, and whether mutations in these proteins lead to alterations in the function of this synapse. These studies will utilize immunological and biochemical fractionation techniques together with myogenic cell culture to identify binding partners for Dlg and CASK and to determine the domains responsible for their localization and protein interactions in skeletal muscle. Transgenic mice will be used to define the functions of Dlg and CASK and their PDZ domains in channel and receptor clustering in skeletal muscle in vivo and provide valuable information about the effect of these receptors on the physiological characteristics of muscle. These studies will lead to important new insights into the roles of PDZ domain proteins in the organization and function of the NMJ and will have important implications for understanding a wide variety of neuromuscular diseases including channelopathies and those disorders for which a cause is unknown.

描述（由申请人提供）：神经递质受体在突触的突触后膜处的聚集对于信号从神经元到其靶的有效传递是必不可少的。在哺乳动物神经肌肉接头（NMJ）的胆碱能神经递质受体聚集的机制和这些神经递质受体的生理已经得到了很好的研究。然而，对其他受体和通道的作用知之甚少，包括NMDA谷氨酸和ErbB4受体，以及也定位于突触后膜的钠通道。含有PDZ蛋白基序的蛋白质家族将通道和受体定位在果蝇NMJ和哺乳动物中枢神经系统突触处，并且被认为在这些突触的组织、结构和功能中发挥基本作用。我们最近已经显示了几个这些PDZ结构域蛋白在哺乳动物NMJ的突触后膜的本地化。这些PDZ结构域蛋白中的两种，Dlg和CASK，代表了与NMDA和ErbB4受体以及NMJ突触后膜处的钠通道相互作用的优秀候选者。本申请的目的是确定Dlg和CASK在骨骼肌中相互作用的蛋白质，这两种蛋白质是否负责将通道和受体定位在NMJ，以及这些蛋白质中的突变是否导致该突触功能的改变。这些研究将利用免疫学和生物化学分离技术以及肌原性细胞培养来鉴定Dlg和CASK的结合伴侣，并确定负责其在骨骼肌中的定位和蛋白质相互作用的结构域。转基因小鼠将被用于定义Dlg和CASK及其PDZ结构域在体内骨骼肌通道和受体聚集中的功能，并提供关于这些受体对肌肉生理特性的影响的有价值的信息。这些研究将导致对PDZ结构域蛋白在NMJ组织和功能中的作用的重要新见解，并将对理解各种神经肌肉疾病（包括通道病和原因不明的疾病）具有重要意义。