Investigating the mechanisms of Arc-dependent synaptic plasticity

这项提案的首要目标是描述调节蛋白质贩运的蛋白质机制的特征 突触后膜蛋白对突触可塑性至关重要。膜蛋白的内吞和胞吐作用是 在所有细胞中都有关键的运输步骤，但在神经元中尤其动态和微调。与突触前不同 内吞作用和突触小泡循环，突触后的精确分子过程 人口贩运仍然定义不清。关于特定受体是如何从蛋白质中移除的，我们知之甚少。 突触后密度(PSD)的支架复合体或蛋白质-蛋白质相互作用的功能作用 在突触可塑性期间的PSD内。我们以前的工作确定了直接早期基因Arc是一种 大脑记忆储存的关键介质，并显示Arc调节AMPA型谷氨酸受体 贩卖人口。我们进行了无偏见的蛋白质组筛选，发现了新的Arc相互作用蛋白。基于 在这些筛选中，我们假设Arc作为一种新的突触后网状蛋白适配器蛋白。在此基础上 假设，我们将测试Arc是否结合脂类、将货物招募到内体(例如AMPAR)并相互作用 与PSD蛋白一起从PSD内的支架上释放受体。来研究蛋白质在体内的运输 突触的纳米结构域我们开发了一种新的活超分辨率光学显微镜方法。这 研究将提供对Arc如何调节多种形式的突触可塑性的机制洞察，还 广泛地阐明了参与突触后膜蛋白运输的蛋白质机制 兴奋性突触。作为一种关键的突触效应蛋白，Arc位于一个关键的神经节上，并被认为与 人类患者的神经和精神障碍。因此，这项工作也将有助于揭示突触 与神经系统疾病相关的功能障碍。

The overarching goal of this proposal is to characterize the protein machinery that mediates trafficking of postsynaptic membrane proteins critical for synaptic plasticity. Endo- and exocytosis of membrane proteins are critical trafficking steps in all cells, but are especially dynamic and finely tuned in neurons. Unlike presynaptic endocytosis and synaptic vesicle recycling, the precise molecular processes that underlie postsynaptic trafficking still remain poorly defined. Little is known about how specific receptors are removed from the protein scaffolding complex at the postsynaptic density (PSD) or the functional role of protein-protein interactions within the PSD during synaptic plasticity. Our previous work identified the immediate early gene Arc as a critical mediator of memory storage in the brain and showed that Arc regulates AMPA-type glutamate receptor trafficking. We conducted unbiased proteomic screens and discovered novel Arc interacting proteins. Based on these screens, we hypothesize that Arc acts as a novel postsynaptic clathrin adaptor protein. Based on this hypothesis, we will test whether Arc binds lipids, recruits cargo to endosomes (e.g. AMPARs) and interacts with PSD proteins to release receptors from their scaffolding within the PSD. To study protein trafficking within nanodomains of synapses we have developed a novel live super-resolution light microscopy approach. This study will provide mechanistic insight into how Arc mediates multiple forms of synaptic plasticity and also broadly elucidates the protein machinery that is involved in postsynaptic trafficking of membrane proteins at excitatory synapses. Arc lies at a critical nexus as a critical synaptic effector protein and has been implicated in neurological and psychiatric disorders in human patients. Thus, this work will also shed light on synaptic dysfunction associated with neurological diseases.