Bioluminescence Resonance Energy Transfer Assay to Characterize Gi-Like G Protein Subtype-Dependent Functional Selectivity

G protein–coupled receptors (GPCRs) comprise the single most targeted protein class in pharmacology. G protein signaling transduces extracellular stimuli such as neurotransmitters into cellular responses. Although preference for a specific GPCR among different G protein families (e.g., Gs-, Gi-, or Gq-like proteins) is often well studied, preference for a specific G protein subtype (e.g., Gi1, Gi2, Gi3, Go1, and Go2) has received little attention. Due to tissue expression differences and potentially exploitable functional differences, G protein subtype-dependent functional selectivity is an attractive framework to expand GPCR drug development. Herein we present a bioluminescence resonance energy transfer (BRET)-based method to characterize functional selectivity among Gi-like protein subtypes. © 2017 by John Wiley & Sons, Inc.