Fig. 3

β-Arrestin recruitment is dispensable for the BILF1 receptor internalization. a SNAP-tagged EBV-BILF1 (green), SNAP-PLHV1-BILF1 (blue), SNAP-PLHV2-BILF1 (orange), and empty vector (gray) were expressed in parental HEK-293A cells (black square) and β-arrestin 1/2 knockout HEK-293A cells (Δβ-arr KO; black circle or white circle for empty vector). The curves represent the ratios between the donors and acceptors. Internalization was measured every 4 min for 88 min at 37 °C. b BILF1 receptors C-terminally tagged with RLuc8 were expressed in HEK-293A cells together with various concentrations of β-arr 2-GFP². BRET2 values are plotted as a function of the ratio between the GFP² (total fluorescence) and RLuc8 (total luminescence) signal. Results are presented as the mean (± SEM) from at least three independent experiments and are fitted using a simple linear regression equation (R). c The table presents the results from the informational spectrum method (ISM), determining the interaction of BILF1 receptors or the β2 adrenergic receptor (β2-AR) with β-arrestin (S/N ratio). A lower S/N ratio indicates lower interaction affinity