FIGURE 4.

Regulation of Thr⁵³ phosphorylation by phorbol ester and okadaic acid. A, rDAT-LLCPK₁ cells were treated with vehicle, 1 μm OA, or 1 μm PMA for 30 min at 37 °C. B, rat striatal synaptosomes were treated with vehicle, 1 μm OA, or 1 μm PMA for 30 min at 30 °C. Lysates were subjected to SDS-PAGE and immunoblotted with Thr(P)⁵³ Ab (pT53Ab) (top) or mAb 16 (bottom) (representative examples shown). Histograms show quantification of Thr(P)⁵³ staining relative to vehicle controls (means ± S.E.; n = 3) (*, p < 0.05; **, p < 0.01; ***, p < 0.001 relative to basal by ANOVA).