Nature, published online: 14 January 2026; doi:10.1038/d41586-026-00011-2
A collection of fluorescently labeled G protein-coupled receptor proteins expressed in living cells has confirmed that when these receptors bind to an activating ligand molecule, they form various complexes with their G proteins. Activation pathways induced by different ligands explain the efficacy of ligands for G protein activation and preferences for G protein subtypes.