Abstract:
The glucagon-like peptide-1 receptor (GLP1R) is a broadly expressed target of peptide hormones with essential roles in energy and glucose homeostasis, as well as of the blockbuster weight-loss drugs semaglutide and liraglutide. Despite its large clinical relevance, tools to investigate the precise activation dynamics of this receptor with high spatiotemporal resolution are limited. Here, we introduce a novel genetically encoded sensor based on the engineering of a circularly permuted green fluorescent protein into the human GLP1R, named GLPLight1. We demonstrate that fluorescence signal from GLPLight1 accurately reports the expected receptor conformational activation in response to pharmacological ligands with high sensitivity (max ΔF/F0=528%) and temporal resolution (τON = 4.7 s). We further demonstrated that GLPLight1 shows comparable responses to glucagon-like peptide-1 (GLP-1) derivatives as observed for the native receptor. Using GLPLight1, we established an all-optical assay to characterize a novel photocaged GLP-1 derivative (photo-GLP1) and to demonstrate optical control of GLP1R activation. Thus, the new all-optical toolkit introduced here enhances our ability to study GLP1R activation with high spatiotemporal resolution.
摘要:
胰高血糖素样肽-1受体(GLP1R)是肽激素的广泛表达靶标,在能量和葡萄糖稳态中具有重要作用,以及重磅炸弹减肥药司马鲁肽和利拉鲁肽。尽管它有很大的临床相关性,研究具有高时空分辨率的这种受体的精确激活动力学的工具是有限的。这里,我们在人类GLP1R中引入了一种基于循环置换绿色荧光蛋白工程的新型基因编码传感器,名为GLPLight1。我们证明,来自GLPLight1的荧光信号以高灵敏度(最大ΔF/F0=528%)和时间分辨率(τON=4.7s)准确地报告了响应药理学配体的预期受体构象激活。我们进一步证明了GLPLight1对胰高血糖素样肽-1(GLP-1)衍生物显示出与天然受体观察到的相当的应答。使用GLPBlight1,我们建立了一种全光测定法,以表征新型的光老化的GLP-1衍生物(光GLP1)并证明GLP1R激活的光学控制。因此,这里介绍的新的全光学工具包增强了我们研究高时空分辨率GLP1R激活的能力.