Interaction of immature receptor dimers with chaperones. HEK293 cells were transfected with AT1R (N4, 176, 188D)-v1/v2 and β2AR (N 4, 15, 176Q)-v1/v2. After 48 hours, cells were harvested, washed, lysed with RIPA and precleared with protein A-sepharose beads. This lysate was distributed into eight different microcentrifuge tubes and co-immunoprecipitations were performed using the indicated chaperone antibody. a) AT1R (ND)/β2AR (NQ) heterodimer, b) AT1R (ND) homodimer, c) β2AR (NQ) homodimer. The eighth sample was loaded as a control to show the expression level of the immature receptor dimers as shown in d. Results are representative of 4 independent experiments.