Fig. 4.

Agonist selective trafficking of the sst2A receptor and EGFP-β-arrestin-2. CHO-K1 cells were transfected with HA-tagged sst2A receptor and EGFP-β-arrestin-2 as described in Materials and Methods and grown for 48 h. Cells were then incubated with HA antibody for 2 h on ice to label cell surface receptors, washed to remove unbound antibody, and treated with 100 nm SS14, 1 μm SOM230, or 1 μm KE108 at 37 C for the times shown. After fixation and permeabilization, cells were incubated with Alexa Fluor 568-conjugated antimouse IgG. Images of antibody-labeled sst2A receptors (red) and EGFP-tagged arrestin (green) from the same cell were acquired with a Nikon A1 confocal microscope. The merged images depict receptor and β-arrestin-2 colocalization (yellow). Shown are representative cells from at least three independent experiments.