FIGURE 2.

Expression of constitutive GPCR activation measured as basal IP accumulation. COS-7 cells transiently co-transfected with the chimeric G-protein (Gα_Δ6qi4myr) and either EGFP only, the purinergic P2Y₁₂ receptor, MOR, or WT-Y1. The IP level accumulated was determined after a 1-h incubation in the absence of an agonist and reported as the relative fold increase relative to the EGFP condition where GPCR expression is absent (EGFP: 1.00; P2Y₁₂: 13.0 ± 1.6; MOR: 2.3 ± 0.3; WT-Y1: 1.2 ± 0.1). ^**, p < 0.01.