Live Cell Bioluminescence Imaging in Temporal Reaction of G Protein-Coupled Receptor for High-Throughput Screening and Analysis

Bioluminescence imaging of G protein-coupled receptor activation in living mice

G protein-coupled receptors (GPCRs), a superfamily of cell-surface receptors involved in virtually all physiological processes, are the major target class for approved drugs. Imaging GPCR activation in real time in living animals would provide a powerful way to study their role in biology and disease. Here, we describe a mouse model that enables the bioluminescent detection of GPCR activation in real time by utilizing the clinically important GPCR, sphingosine-1-phosphate receptor 1 (S1P₁). A synthetic S1P₁ signaling pathway, designed to report the interaction between S1P₁ and β-arrestin2 via the firefly split luciferase fragment complementation system, is genetically encoded in these mice. Upon receptor activation and subsequent β-arrestin2 recruitment, an active luciferase enzyme complex is produced, which can be detected by in vivo bioluminescence imaging. This imaging strategy reveals the dynamics and spatial specificity of S1P₁ activation in normal and pathophysiologic contexts in vivo and can be applied to other GPCRs.

G protein-coupled receptors are involved in numerous physiological functions, thus, they represent potential pharmaceutical targets. Here Kono et al. describe a new mouse model to image GPCR activation in real-time by exploiting firefly split luciferase fragment complementation that can be detected by bioluminescence imaging.