FIGURE 4.

The dimerization of GHSR1a/OX1R and effects of interfering peptides on GHSR1a/OX1R heterodimers. (A) HEK293 cells were either not transfected (mock) or transfected with HA–OX1R, Myc–GHSR1a or both (co-transfection). As negative control, samples containing either HEK293 HA–OX1R cells or HEK293 Myc–GHSR1a cells were mixed (Mix). Cell lysates were immunoprecipitated with anti-HA agarose beads and immunoblotted with anti-Myc antibody (upper panel). Cell lysates were examined by immunoblotting with either an anti-Myc or anti-HA antibody (lower panels). The data represent means ± SEM (N = 3) of four independent experiments. (B) HEK293 cells were co-transfected with OX1R-Rluc and GHSR1a-EYFP (1:3) and incubated at 37°C for 2 h with HIV TAT–fused TM peptides (10 μM) corresponding to TM1, TM5, or TM7 of OX1R. BRET ratios were analyzed and are expressed as the means ± SEM (N = 3) of four experiments (one-way analysis of variance; ns, not significant, p > 0.05; ^∗∗p < 0.01 vs. control group).