Fig. 1
From: Lack of beta-arrestin signaling in the absence of active G proteins
G protein activation and βarr2 recruitment in absence and presence of active G proteins. a PGD2-mediated depression of cAMP production in DP2-HEK293 cells, in the absence or presence of PTX. b Representative real-time FRET ratios and summary of Gi2 protein rearrangement after stimulation with PGD2 in DP2 expressing wild-type (WT) cells in absence and presence of PTX. c β-arrestin2 recruitment to PGD2-stimulated DP2 receptors, in the absence or presence of PTX. d Effect of MDL on the production of cAMP by Gi/q-linked GPR17, in the absence or presence of PTX. e IP1 accumulation of MDL-activated GPR17, in the presence or absence of FR. f, g Gi2 (f) and Gq (g) protein rearrangement in GPR17 expressing wild-type (WT) cells stimulated with MDL in absence and presence of G protein inhibitors. h, i β-arrestin2 recruitment to MDL-stimulated GPR17 when Gi/q is inhibited with PTX and FR (h) or when the entire complement of cellular Gα proteins (ΔGsix+PTX) is inactivated (i). Shown are representative FRET traces with the indicated number of total cells per condition (b, f, g) and bar diagrams are averages from three independent experiments. Data are mean ± s.e.m. (a, c, d, h, i) or + s.d. (b, e, f, g) of three (a–g, i) and four (h) experiments (three technical replicates each). For statistical analysis, two-tailed unpaired t-test (b, f, g) and two-sample paired Wilcoxon test (h, i) was applied to paired points at different concentrations. *P < 0.05; **P < 0.01; not significant where no asterisk
