Probing synaptic protein interactions in a vesicular model system

神经细胞的突触前末梢是生物体中最繁忙和复杂的地方之一。其主要目的是以毫秒时间尺度携带动作电位，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的突触前蛋白质带头的，这是本研究的重点。许多突触前蛋白直接涉及神经退行性疾病，如阿尔茨海默病和帕金森病。目前，我们对突触蛋白的确切作用以及它们如何导致神经系统病理学的认识非常不足。本研究的目的是开发一种体外囊泡模型系统，这将提供一个平台，用于研究蛋白质-蛋白质相互作用下更多的生理相关的蛋白质的条件和构象，而不仅仅是在一个解决方案。此外，该模型系统将是一个通用的平台，通过溶液和固态NMR，Förster共振能量转移（FRET）和荧光相关光谱（FCS）的结构和功能的研究。该技术将极大地帮助蛋白质-蛋白质相互作用，定义结合动力学，并以高度受控，系统和可重复的方式揭示其相互作用的关键结构信息。此外，几个关键因素，如蛋白质翻译后修饰，SUV组合物和金属离子参与细胞信号转导建议有助于突触前蛋白质-蛋白质与其他蛋白质的相互作用也可以探索。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。该研究旨在以一种新的方式研究突触前蛋白，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好地理解内在无序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.