Structure-function of the α4β2 nicotinic acetylcholine receptor in a lipidic environment

项目摘要（1-2帕拉）： 烟碱型乙酰胆碱受体是配体门控离子通道，广泛表达于全身， 中枢和外周神经系统。α4β2烟碱受体是大脑中最丰富的亚型 并与尼古丁成瘾和神经系统疾病，包括阿尔茨海默氏症和帕金森氏症有关。 在体外和大脑中长期暴露于尼古丁可上调α4β2受体的表达。 吸烟者与不吸烟者相比。因此，已经做出了广泛的努力， 分子通过靶向这种受体类型来减少烟草成瘾，但这些努力受到了 尼古丁受体的结构信息有限。一种去敏化态烟碱的原子结构 通过X射线晶体学和Cryo-EM获得的洗涤剂中的受体是已知的，但是高分辨率结构 在生理学相关的神经系统环境中的作用仍然没有得到解决。此外，我们缺乏结构信息， 这种受体在不同的状态沿着门控周期。在这里，我建议首先确定脂质的组合， 其支持使用电生理学方法的鲁棒通道功能。同时，我将优化样本 制备α4β2烟碱受体的生物纳米盘，利用来自功能性 在特定的环境中进行研究。我将用这些制剂获得高分辨率的结构 α4β2烟碱受体在不同构象状态下的信息，在实验条件下， 直接用于生理制剂。膜和不同细胞中受体的结构信息 构象状态将为理解这些受体的变构门控提供试金石， 用于开发状态选择性药理学工具和疗法的模板。

Project summary (1-2 para): Nicotinic acetylcholine receptors are ligand-gated ion channels that are widely expressed throughout the central and peripheral nervous systems. The α4β2 nicotinic receptor is the most abundant subtype in the brain and is linked to nicotine addiction and neurological disorders including Alzheimer's and Parkinson's diseases. Expression of the α4β2 receptor is upregulated by chronic exposure to nicotine in vitro and in the brains of smokers compared to that of non-smokers. Accordingly, there have been extensive efforts to develop small molecules to reduce tobacco addiction by targeting this receptor type, but these efforts are hampered by the limited amount of structural information for nicotinic receptors. Atomic structures of a desensitized-state nicotinic receptor in detergent obtained by X-ray crystallography and Cryo-EM are known, but high-resolution structures in a physiologically relevant lipidic environment remain unresolved. Moreover, we lack structural information for this receptor in the different states along the gating cycle. Here I propose to first identify combinations of lipids that support robust channel function using electrophysiological approaches. In parallel I will optimize sample preparation for the α4β2 nicotinic receptor in lipidic nanodiscs, leveraging the information from the functional studies in defined lipidic environments. I will use these preparations to obtain high resolution structural information for the α4β2 nicotinic receptor in distinct conformational states, in an experimental condition tied directly to a physiological preparation. Structural information for the receptor in a membrane and in different conformational states will provide touchstones for understanding allosteric gating of these receptors and templates for development of state-selective pharmacological tools and therapeutics.