Probing synaptic protein interactions in a vesicular model system

神经细胞的突触前终末是生物体中最繁忙和最复杂的地方之一。它的主要目的是携带毫秒级的动作电位，这需要神经递质的快速和高度特异性的囊泡运输。这项艰巨的任务是由大量突触前蛋白带头的，这些蛋白是本研究的重点。许多突触前蛋白直接与阿尔茨海默氏症和帕金森氏症等神经退行性疾病有关。目前，我们非常缺乏对突触蛋白所起的确切作用以及它们如何在神经系统病理中起作用的阐述。本研究旨在开发一种体外囊泡模型系统，为研究蛋白质与蛋白质在更多生理条件和构象下的相互作用提供平台，而不是仅仅在溶液中。此外，该模型系统将成为通过溶液和固体核磁共振、Förster共振能量转移(FRET)和荧光相关光谱(FCS)进行一些结构和功能研究的通用平台。这些技术将极大地帮助描述蛋白质-蛋白质相互作用的特征，定义结合动力学，并以高度受控、系统和可重复性的方式揭示关于它们相互作用的关键结构信息。此外，还可以探索一些关键因素，如蛋白质翻译后修饰、SUV组成和参与细胞信号传递的金属离子，这些因素可能有助于突触前蛋白质与其他蛋白质的相互作用。最终，这个平台可以应用于研究其他突触前蛋白的相互作用。这项研究试图以一种新的方式观察突触前蛋白，并确定蛋白质-蛋白质相互作用的结构特征。这也将有助于我们更大程度地低估内在无序的蛋白质如何表现出对其他分子的特异性，并有望丰富我们对阿尔茨海默氏症和帕金森氏症等神经退行性疾病的知识。

The pre-synaptic terminal of a neural cell is one of the busiest and complex places in an organism. Its main purpose is to carry an action potential at a millisecond-time scale, which requires rapid and highly specific vesicular transport of neurotransmitters. This tremendous task is spearheaded by a vast array of pre-synaptic proteins, which are the key focus of this study. A number of pre-synaptic proteins are directly implicated in neurodegenerative diseases such as Alzheimer's and Parkinson's disease. Currently, we greatly lack in understating of the exact role synaptic proteins play and how they contribute to nervous system pathologies. This study aims to develop an in vitro vesicular model system which would provide a platform for studying protein-protein interactions under more physiologically relevant protein conditions and conformations than only in a solution. Furthermore, the model system would be a universal platform for a number of structural and functional studies by solution and solid-state NMR, Förster resonance energy transfer (FRET) and fluorescence correlation spectroscopy (FCS). The techniques would greatly aid to characterise protein-protein interactions, define binding kinetics and reveal key-structural information on their interactions in a highly-controlled, systematic and reproducible way. In addition, several key-factors such as protein post-translational modifications, SUV compositions and metal ions involved in cellular signalling suggested to contribute presynaptic protein-protein interactions with other proteins can also be explored. Eventually, this platform could be applied to study the interactions of other pre-synaptic proteins. The study seeks to look at pre-synaptic proteins in a novel way and identify structural features of protein-protein interactions. It would also contribute to our greater understating of how intrinsically disordered proteins manifest their specificity towards other molecules and hopefully enrich our knowledge on neurodegenerative diseases such as Alzheimer's and Parkinson's.