Photo-induced receptor confinement drives ligand-independent GPCR signaling

Cell-cell communication relies on the assembly of receptor-ligand complexes at the plasma membrane. The spatiotemporal receptor organization has a pivotal role in evoking cellular responses. We studied the clustering of heterotrimeric guanine nucleotide–binding protein (G protein)–coupled receptors (GPCRs) and established a photo-instructive matrix with ultra-small lock-and-key interaction pairs to control lateral membrane organization of hormone neuropeptide Y₂ receptors in living cells by light. Within seconds, receptor clustering was modulated in size, location, and density. After <em>in-situ</em> confinement, changes in cellular morphology, motility, and calcium signaling revealed ligand-independent receptor activation. This approach may enhance exploration of mechanisms in cell signaling and mechanotransduction.