Figure 3

K327R mutation eliminates β-arrestin2 recruitment. HEK-293T cells were transfected with pCEFL-AU5 plasmid (mock), containing in frame wild type (WT), K327R (R1), and K337R (R2) mutant forms of FL CXCR2. One day later, cells were starved (control) or exposed to IL-8 (50 ng/ml, 15 min). a-b. Cells were additionally transfected with β-arrestin2-GFP (βarr2) and the percentage of cells with clustered β-arrestin2-GFP staining was evaluated. Results are expressed as the mean ± sem, n = 150 cells. c. BRET analysis was performed as described in methods, ΔmBRET was calculated and the mean ± sem is shown. Each panel is representative of three independent experiments. Scale bars: 10 μm. **p < 0.01, ***p < 0.001.