Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University.
Department of Neurosurgery, West China Hospital, Sichuan University.
J Vis Exp. 2022 Jun 8(184). doi: 10.3791/64054.
Lysophospholipids (LPLs) are bioactive lipids that include sphingosine 1-phosphate (S1P), lysophosphatidic acid, etc. S1P, a metabolic product of sphingolipids in the cell membrane, is one of the best-characterized LPLs that regulates a variety of cellular physiological responses via signaling pathways mediated by sphingosine 1-phosphate receptors (S1PRs). This implicated that the S1P-S1PRs signaling system is a remarkable potential therapeutic target for disorders, including multiple sclerosis (MS), autoimmune disorders, cancer, inflammation, and even COVID-19. S1PRs, a small subset of the class A G-protein coupled receptor (GPCR) family, are composed of five subtypes: S1PR1, S1PR2, S1PR3, S1PR4, and S1PR5. The lack of detailed structural information, however, impedes the drug discovery targeting S1PRs. Here, we applied the cryo-electron microscopy method to solve the structure of the S1P-S1PRs complex, and elucidated the mechanism of activation, selective drug recognition, and G-protein coupling by using cell-based functional assays. Other lysophospholipid receptors (LPLRs) and GPCRs can also be studied using this strategy.
溶血磷脂（LPLs）是一类生物活性脂质，包括鞘氨醇 1-磷酸（S1P）、溶血磷脂酸等。S1P 是细胞膜鞘脂代谢产物，是通过鞘氨醇 1-磷酸受体（S1PRs）介导的信号通路调节多种细胞生理反应的最具特征性的 LPL 之一。这表明 S1P-S1PRs 信号系统是多种疾病的一个显著的潜在治疗靶点，包括多发性硬化症（MS）、自身免疫性疾病、癌症、炎症，甚至 COVID-19。S1PRs 是 A 类 G 蛋白偶联受体（GPCR）家族的一个小亚类，由五个亚型组成：S1PR1、S1PR2、S1PR3、S1PR4 和 S1PR5。然而，缺乏详细的结构信息阻碍了针对 S1PRs 的药物发现。在这里，我们应用冷冻电子显微镜方法解决了 S1P-S1PRs 复合物的结构，并通过基于细胞的功能测定阐明了激活、选择性药物识别和 G 蛋白偶联的机制。该策略还可以用于研究其他溶血磷脂受体（LPLRs）和 GPCRs。
