Fig. 6.

MC1R mutations have no effect on NDP-MSH binding affinity. HEK293 cells in 24-well plates were transiently transfected with wild-type or variant receptors. Forty-eight hours later, [¹²⁵I]NDP-MSH radioligand binding with increasing concentrations of unlabeled α-MSH was evaluated. Cells were incubated for 2 h at room temperature in the absence or presence of unlabeled α-MSH at the indicated concentrations. Data points represent the mean ± S.E.M from at least four independent experiments, each performed in triplicate. Data are expressed as a percentage of radioligand binding to the wild-type receptor in the absence of cold α-MSH.