FIGURE 4.

Orexin A is more potent in causing internalization of CB₁ receptor than OX₁ receptor. Cells of clones B6 (A) and C2 (B) were induced to express the harbored receptor by treatment with doxycycline. The ability of different concentrations of orexin A to cause internalization of CB₁ (filled symbols) and OX₁ receptors (open symbols) was assessed in parallel by measuring binding of either SNAP-Lumi4Tb or CLIP-Lumi4Tb to intact cells. In both cases, orexin A (OxA) was more potent in producing internalization of the CB₁ receptor than the OX₁ receptor. Data are means ± S.E. (n = 3 in each case). VS, VSV-G + SNAP tag; HC, HA + CLIP tag.