Figure 2. C-terminal truncation of the orexin-1 receptor prevents sustained interactions with β-arrestin-2 but not agonist-induced internalization.

A series of C-terminal truncation mutants of the HA-tagged orexin-1 receptor was generated (A). These were transfected into HEK-293T cells along with β-arrestin-2–GFP. The cells were then stimulated with orexin A (0.5 μM, 30 min) in the presence of anti-HA antibody and visualized following permeabilization and addition of secondary antibody. Representative data are shown for the 394-Stop (B) and 374-Stop (C) mutants. The distribution of the orexin-1 receptor (i), β-arrestin-2 (ii) and a composite of these images (iii) are shown.