Engineering the Melanocortin-4 Receptor to Control Constitutive and Ligand-Mediated Gs Signaling In Vivo
Figure 6
HEK293 cells stably expressing wild-type MC4R (A), Rm1 (L106P) (B), and Rm2 (D122A) (C) were exposed to increasing concentrations of α-MSH or THIQ for 2 h.
Cell-surface FLAG-tagged receptors were measured by ELISA. Receptor sequestration was calculated as the loss of receptor expression from the cell surface. Wild-type MC4R was internalized significantly more (p<0.05) in response to α-MSH than THIQ at doses of 10−7 M and higher. Data represent the mean±s.e.m. of two independent experiments, each performed in quadruplicate.