On Vibronic-Driven Action and Mechanosensitive G Protein-Coupled Receptors

G protein-coupled receptors (GPCR) are targeted by more than one third of the clinically available drugs as specific ligands. Important as GPCR ligands may be, cases of ligand-independent GPCR activation are also abundant. In a recent article published in the journal ACS Nano, a series of cyanine skeleton-based plasmonic molecules, or molecular jackhammer, as the authors christened them, after insertion into the plasma membrane, was found after excitation by far-red light (730 nm) to vibronically-driven activate Gq-mediated calcium signaling in four different cell lines of both epithelial and muscle cell origin, which is normally activated after agonist stimulation of Gq-coupled GPCR, but the possible involvement of GPCR remains to be examined. This novel mode of activation of calcium signaling, normally associated with agonist-stimulated GPCR activation, is compared to nanoclustering activation of the neuropeptide Y2 receptor and photodynamic activation of the cholecystokinin 1 and 2 receptors.