Fig. 3.
Characterization of human/mouse chimeric A3ARs. (A) Cartoon depicting the makeup of each chimeric receptor. (B) [35S]GTPγS binding assays. Concentration-response curves with Cl-IB-MECA were conducted in the presence of vehicle (DMSO, black) or 0.1 (yellow), 1 (blue), or 10 μM (magenta) LUF6000. Results were normalized to the Emax value of Cl-IB-MECA obtained in the presence of vehicle. The dotted line in each graph demarcates the Emax of Cl-IB-MECA in the presence of 10 μM LUF6000 with membranes from wild-type A3ARs (240 ± 11% of vehicle). (C) [125I]I-AB-MECA dissociation binding assays. The allosteric actions of LUF6000 were lost in assays with the H/MTMD7/H8/CT chimera and diminished in assays with the H/MTMD1-2/ICL1 chimera. EC50, Emax, and k values are reported in Supplemental Table 2. Data are presented as the mean ± S.D.