Figure 1.

Activation of HA-MAPK by α_z and mutants. cDNAs encoding D₂R and either α_z-WT, α_z-G2A, α_z-C3A, α_z-G2AC3A, or vector were transfected into CHO-K1 cells. Cells were serum starved for 24 h. After 4 h of pretreatment with or without PTX, cells were treated with serum-free medium (basal) or 10 μM quinpirole for 7 min. HA-MAPK activity was measured as described in MATERIALS AND METHODS. Bars, mean ± 2 SE of triplicate determinations. Similar results were obtained in two additional experiments.