FIGURE 8.
Effect of overexpressing arrestin2 or arrestin3 on D2 DAR desensitization. HEK293T cells were transfected with the wild-type D2L DAR along with either empty vector (pcDNA), arrestin2 (arr2) (A), or arrestin3 (arr3) (B) expression constructs. Cells were preincubated in the absence or presence of 10 μm DA for 3 h followed by membrane preparation and [35S]GTPγS binding assays as described under “Experimental Procedures.” The amount of DA-stimulated [35S]GTPγS binding is expressed as the percent maximum observed in the control (no DA pretreatment) group. Single representative experiments are shown, which were replicated two times with identical results.