FIG. 3.

BRF1 is phosphorylated in vivo at serine 203. (A) HIRc-B cells were transfected with BRF1wt or BRF1S203A and stimulated with insulin (20 μg/ml) or 400 nM OA for 30 min at 48 h after transfection. Where indicated, cells were pretreated with WM (200 nM) 15 min before stimulation. Cell lysates were probed with the anti-phospho-Ser203 BRF1 antibody and against anti-phospho-Ser473 PKB to show the correlation between BRF1 Ser203 phosphorylation and PKB activity. (B) NIH 3T3 cells were transfected with BRF1wt or BRF1S203A and stimulated with 400 nM OA for 30 min. The phospho-S203-specific signal is indicated on the left of each panel.