Fig. 3

Homodimerization of CXCR7 on the membrane surface. a HEK293 cells expressing epitope-tagged forms of CXCR4 or CXCR7 were used for immunoprecipitation with anti-FLAG agarose and subsequent western blot analysis with anti-HA antibodies. Cross-linking experiments were performed as described in Materials and Methods. b Luminescence produced by receptor dimerization. NanoBiT constructs for each receptor were expressed in HEK293 cells. c NanoBiT constructs of CXCR7 and β-arrestin2 were co-expressed with different promoter constructs of CXCR7 (HSV-TK, UbiC, CMV) or empty vector (V) in HEK293 cells. Cells were treated with SDF-1α or not (V/Veh), and then luminescence was measured. Results are the average of three independent experiments. Values are presented as the mean ± SD. *p < 0.05, **p < 0.001