(Toshiki Yoda, Yasushi Sako, Asuka Inoue, Masataka Yanagawa, Biophysics and Physicobiology 21, e210020 (2024), DOI: 10.2142/biophysico.bppb-v21.0020))
G-protein-coupled receptor (GPCR) acts as a conductor that orchestrates multiple intracellular signaling proteins. When observing the single GPCR molecules in a living cell for the first time, one is captivated by the dynamic feature each molecule moves around on the plasma membrane. Upon stimulation, GPCRs repeatedly encounter and part with various partners before clustering and undergoing endocytosis. This illustration depicts actual GPCR trajectories observed using a four-color single-molecule imaging microscopy system. LgBiT-tagged GPCRs were labeled with four distinct FiBiT peptides conjugated to different fluorophores, enabling simultaneous multi-color tracking. This approach provides unprecedented insights into the spatiotemporal dynamics of GPCR signaling, clustering, and internalization in live cells, advancing our understanding of these crucial signal transduction mechanisms. (PDB ID: GPCR [V2R:7BB7], LgBiT-FiBiT [NanoBiT: 7SNX])