The Role of Sam68 in Synaptic Transmission and Plasticity

描述（由申请人提供）：本项目旨在描述rna结合蛋白Sam68在突触传递和可塑性中的新作用。Sam68是含有kh结构域的蛋白家族的成员，该蛋白家族通过其对突触传递的影响与几种神经疾病的发病机制有关。例如，kh家族成员FMRP的突变导致脆性X智力迟钝综合征，而kh家族成员QUAKING的突变与精神分裂症有关。最近的两项研究表明，Sam68参与脆性X震颤/共济失调综合征和脊髓性肌萎缩的发病机制。阐明Sam68在维持有效突触传递中的作用将为了解含kh结构域蛋白家族的功能障碍，特别是Sam68，如何导致神经系统疾病提供有价值的见解。Sam68可能在突触中发挥双重作用，首先作为通过NMDA受体运输的突触传递的调节剂，其次作为树突棘局部蛋白质合成的调节剂。该建议包括在电生理学和分子生物学领域进行一些高级实验室技能的培训，以便对Sam68在突触中的作用进行详细的调查。为了研究Sam68缺失的影响，我们将使用体内分子操作（例如病毒注射），以及一组使用Sam68缺失小鼠的免费实验。我们将使用全细胞膜片钳记录和定量免疫组织化学来检测Sam68缺失对NMDA受体运输的影响。我们将使用荧光原位杂交和光转换荧光蛋白Dendra2来检测Sam68调节树突棘局部蛋白质合成的能力。Sam68可能通过参与涉及受体运输和局部蛋白质合成的活动依赖性变化，代表了突触可塑性的一种新的调节剂。

DESCRIPTION (provided by applicant): The goal of this project is to describe a novel role for the RNA-binding protein Sam68 in synaptic transmission and plasticity. Sam68 is a member of the KH-domain containing family of proteins, which have been linked to the pathogenesis of several neurological disorders via their effects on synaptic transmission. For example, mutations in the KH-family member FMRP result in Fragile X Mental Retardation Syndrome, while mutations in the KH-family member QUAKING have been implicated in Schizophrenia. Two recent studies suggest that Sam68 is involved in the pathogenesis of Fragile X Tremor/Ataxia Syndrome, and Spinal Muscular Atrophy. Elucidation of Sam68's role in maintaining efficient synaptic transmission will provide valuable insights into how dysfunction of the family of KH-domain containing proteins, and Sam68 in particular, leads to neurological disease. Sam68 may serve dual roles at the synapse, first as a modulator of synaptic transmission through NMDA receptor trafficking, and second as a regulator of local protein synthesis at dendritic spines. This proposal includes training in a number of advanced laboratory skills in the fields of electrophysiology and molecular biology in order to conduct a detailed investigation of Sam68's role at the synapse. To study the effects of loss of Sam68 we will use in vivo molecular manipulations (e.g. viral injections), in addition to a complimentary set of experiments using a line of Sam68 null mice. We will examine the effect of loss of Sam68 on NMDA receptor trafficking using whole cell patch clamp recording and quantitative immunohistochemistry. We will examine the ability of Sam68 to regulate local protein synthesis at dendritic spines using fluorescence in situ hybridization, and the photoconvertable fluorescent protein Dendra2. Sam68 may represent a novel regulator of synaptic plasticity by participating in activity-dependent changes involving both receptor trafficking, and local protein synthesis. PUBLIC HEALTH RELEVANCE: Neurological disorders may arise from inefficiencies in the mechanisms that ensure proper communication between neurons in the central nervous system. This project aims to understand the role of the RNA-binding protein Sam68 in ensuring proper neuronal transmission. Understanding this role will be helpful for guiding the development of therapies for neurological disorders resulting from dysfunction of Sam68 and related proteins.