P2X受体是感受胞外三磷酸腺苷（ATP）的阳离子通道，共有P2X1-7七个亚型。P2X亚型选择性的激动或增强调节在抑郁症、酒精使用障碍和糖尿病等疾病干预中具有很大潜力。由于P2X各亚型正交位点同源性极高，激动剂ATP的类似物难表现出亚型选择性，且成药性差。因此，深入发掘P2X各个亚型选择性正性变构调节机制和发现对应的增强分子更为迫切。申请人致力于P2X门控与调节机制研究（PNAS, 2018; Nat Commun, 2014），为靶向P2X的先导分子发现提供了基础。在前期预实验中，已发现P2X3和P2X4选择性的正性变构调节剂。本项目拟以此为基础，综合运用分子药理学、单分子荧光成像、转基因动物的疾病模型和复杂体系的分子模拟等多技术手段，研究正性变构调节剂的作用位点、变构机制和功能。基于这些机制，发现、设计和优化更多P2X亚型选择性增强分子，为防治P2X异常相关疾病提供新的策略和先导分子。

P2X receptors are non-selective cation channels gated by extracellular ATP. So far, seven subtypes of P2X receptors in mammals were identified, namely, P2X1-7. Subtype-specific positive regulations or direct activations of P2X receptors have attracted great interest given their potential roles in intervention of various diseases, such as depression, alcohol use disorders, diabetes and hypertension. Taking consideration of extremely high conservation properties of the orthosteric site throughout P2X receptor family, the analogues of ATP could not be directly used in the treatment of those diseases for their non-selective and unstable properties. Therefore, it is urgent to explore underlying positive allosteric mechanisms of P2X receptors and find positive allosteric modulators. The applicant has dedicated himself for a long time in studying the gating mechanism of P2X receptors (PNAS, 2018; Nat Commun, 2014), laying the foundation for the discovery of lead compounds targeting P2X. In the preliminary experiments before the application, the applicant has discovered a few P2X subtype-selective positive allosteric modulators. Here, the applicant will combine the using of molecular pharmacology, single-molecule fluorescent labeling, transgenic animal models and molecular modeling, to study the binding site, allosteric mechanism and pharmacological function of positive allosteric modulators. Based on this result, the applicant intends to further design, optimize and identify more P2X1-7 subtype-selective positive modulators, aiming at providing new strategies and lead compounds for the treatment of P2X-related diseases in future.