5-HT2AR and D2R co-immunoprecipitate. A, Specific co-immunoprecipitation of 5-HT2AR and D2R in HEK293 cells. RLuc-tagged D2R and GFP-tagged 5-HT2AR were immunoprecipitated using anti-GFP or RLuc antibodies. Membranes were probed with either anti-RLuc antibody or anti-N-Cadherin antibody. The co-immunoprecipitated receptor complex is indicated by the box in the upper right panel. B, RLuc-tagged D2R and GFP-tagged 5-HT2AR, mGluR2 or mGluR3 were immunoprecipitated using anti-RLuc antibody and membranes were probed with anti-GFP antibody. A co-immunoprecipitated receptor is detected only for D2R with 5-HT2AR. C, RLuc-tagged D2R and GFP-tagged D2R, 5-HT2AR, mGluR2 or mGluR3 were immunoprecipitated using anti-GFP antibody and membranes were probed with anti-RLuc antibody. Complex formation was observed only for D2R homomers and D2R-5-HT2AR heteromers. Panels are representative of three independent experiments. WB, western blot. IP, immunoprecipitation.