RGS14 adopts different conformations in response to binding Gα proteins in different activation states. HEK 293 cells were transfected with 5 ng of plasmid cDNA encoding Venus-RGS14-Luc alone or with 50, 100, 250, 500, or 750 ng of Gαi1. Gαi1 was activated with AlF4− for 40 min. BRET ratios were recorded, and the change in BRET (ΔBRET) was calculated by subtracting the BRET signal from Venus-RGS14-Luc alone. Average basal BRET for Venus-RGS14-Luc in the absence of AlF4− was 0.693, whereas in the presence of AlF4−, the basal BRET was 0.687. Data shown are the pooled mean ± S.E. of three separate experiments, each with triplicate determinations. The bottom panel shows representative immunoblots (IB) for Venus-RGS14-Luc and Gαi1 protein expression. The inset diagrams illustrate the interpreted dynamics of Venus-RGS14-Luc structure in response to binding Gαi1 in different activation states.