PDF(Pubmed)
Abstract：
Beta-adrenergic receptors (βARs) are G protein-coupled receptors (GPCRs) that mediate catecholamine hormone-induced stress responses, such as elevation of heart rate. Besides those that are plasma membrane-bound, endomembrane βARs are also signaling competent. Dysregulation of βAR pathways underlies severe pathological conditions. Emerging evidence indicates pathological molecular signatures in deeper endomembrane βARs signaling, likely contributing to conditions such as cardiomyocyte hypertrophy and apoptosis. However, the lack of approaches to control endomembrane β1ARs has impeded linking signaling with pathology. Informed by the β1AR-catecholamine interactions, we engineered an efficient photolabile proligand (OptoIso) to trigger βAR signaling exclusively in endomembrane regions using blue light stimulation. Not only does OptoIso undergo blue light deprotection in seconds, but also efficiently enters cells and allows examination of G protein heterotrimer activation exclusively at endomembranes. OptoIso also allows optical activation of plasma membrane βAR signaling in selected single cells with native fidelity, which can be reversed by terminating blue light. Thus, OptoIso will be a valuable experimental tool to elicit spatial and temporal control of βAR signaling in user-defined endomembrane or plasma membrane regions in unmodified cells with native fidelity.
摘要：
β-肾上腺素能受体（βARs）是G蛋白偶联受体（GPCRs），介导儿茶酚胺激素诱导的应激反应，如心率升高。除了那些与质膜结合的物质，内膜βARs也有信号传导能力。βAR途径的失调是严重病理状况的基础。新出现的证据表明，在较深的内膜βARs信号中的病理分子特征，可能导致心肌细胞肥大和凋亡等疾病。然而,缺乏控制内膜β1ARs的方法阻碍了信号与病理学的联系。由β1AR-儿茶酚胺相互作用引起，我们设计了一种有效的光不稳定的前配体（OptoIso），使用蓝光刺激仅在内膜区域触发βAR信号。OptoIso不仅在几秒钟内进行蓝光脱保护，而且还可以有效地进入细胞，并允许仅在内膜上检查G蛋白异源三聚体的激活。OptoIso还允许以天然保真度在选定的单细胞中光学激活质膜βAR信号，可以通过终止蓝光来逆转。因此，OptoIso将是一种有价值的实验工具，可以在用户定义的内膜或质膜区域中以天然保真度对未修饰细胞中的βAR信号进行时空控制。
