Structure and regulation of synaptic architecture

描述（由申请人提供）： 该建议描述了一套研究途径，将用于开发一个独立的研究计划，在调节突触结构。主要的科学目标是了解信号转导通路和肌动蛋白细胞骨架调节剂之间的关系如何控制果蝇突触的细胞结构。神经元必须将胞吐作用、胞内囊泡和蛋白质运输、胞吞作用、细胞粘附、形态变化和局部蛋白质合成紧密联系起来，以实现适当的连接和突触活性。细胞骨架将所有这些过程连接在一起，但不知道如何连接。一种关键的信号响应性肌动蛋白结合蛋白是WASp（Wiskott-Aldrich综合征蛋白），其通过Cdc 42和SH 3结构域蛋白下游的Arp 2/3复合物激活肌动蛋白丝成核。Nwk（Nervous Wreck）是一种保守的神经元WASP激活蛋白，定位于突触活动周区。在没有Nwk的情况下，果蝇遭受温度敏感性癫痫发作，突触终扣大小和神经递质释放减少，并表现出过度生长的神经肌肉接头。因此，Nwk是通过WASp对Arp 2/3复合物进行突触调节的优秀候选者。Nwk-WASp相互作用参与突触生长因子信号复合物的内体运输，但肌动蛋白聚合在此过程中的功能尚不清楚。该提案的科学目标是（1）确定保守的Nwk相互作用蛋白如何有助于其在内体运输中的功能;以及（2）获得周活动区（参与突触囊泡再循环以及细胞粘附和突触生长的突触的专门子域）中内吞和内体结构的高分辨率图像，以深入了解其功能。本计画的训练目标是发展电子断层摄影技术，以高解析度成像突触生长所涉及的亚细胞区域。突触生长的失调是许多神经系统疾病的标志，包括癫痫、阿尔茨海默病和智力迟钝。WRP（NWK的人类同源物）的突变与遗传性儿童智力迟钝有关。因此，阐明保守的亚细胞运输途径和结构的调控NWK将有助于解释人类疾病，并提供新的治疗目标。

DESCRIPTION (provided by applicant): This proposal describes a set of research avenues that will be used to develop an independent research program in regulation of synaptic architecture. The primary scientific goal is to understand how the relationship between signal transduction pathways and actin cytoskeleton regulators controls cellular structures in Drosophila synapses. Neurons must intimately link exocytosis, intracellular vesicle and protein transport, endocytosis, cell adhesion, morphological change and local protein synthesis to achieve appropriate connectivity and synaptic activity. The cytoskeleton links all these processes together but it is not known how. One key signal-responsive actin-binding protein is WASp (Wiskott-Aldrich Syndrome protein), which activates actin filament nucleation by the Arp2/3 complex downstream of Cdc42 and SH3 domain proteins. Nwk (Nervous Wreck) is a conserved neuronal WASp-activating protein that localizes to synaptic periactive zones. In the absence of Nwk, flies suffer from temperature-sensitive seizures, have reduced synaptic bouton size and neurotransmitter release, and exhibit overgrowth of the neuromuscular junction. Therefore, Nwk is an excellent candidate for synaptic regulation of the Arp2/3 complex via WASp. Nwk- WASp interactions are involved in endosomal traffic of synaptic growth factor signaling complexes but the function of actin polymerization in this process is not understood. The scientific goals of this proposal are (1) to determine how a conserved Nwk-interacting protein contributes to its function in endosomal traffic; and (2) to obtain high resolution images of endocytic and endosomal structures in periactive zones, a specialized subdomain of the synapse involved in both recycling of synaptic vesicles and in cell adhesion and synaptic growth, to gain insight into their function. The training goals of this proposal are to develop electron tomography techniques for high resolution imaging of subcellular domains involved in synaptic growth. Misregulation of synaptic growth is a hallmark of many neurological diseases, including epilepsy, Alzheimer's disease and mental retardation. Mutations in WRP, a human homolog of NWK, have been linked to inherited childhood mental retardation. Therefore, elucidation of the conserved subcellular trafficking pathways and structures regulated by NWK will help interpret human diseases and provide new targets for therapies.