Fig. 2.

As₂O₃-dependent phosphorylation of TAK1 in leukemic cell lines. A, NB4 cells were incubated in the absence or presence of As₂O₃ (2 μM) for the indicated times. Equal amounts of total cell lysates were resolved by SDS-PAGE and immunoblotted with an anti-phospho-TAK1 (Ser412) antibody (top). The same blot was reprobed with an anti-GAPDH antibody to control for protein loading (bottom). B, as in A, but using KT-1 cells. C, as in A, but using NB4.306 cells. D, KT-1 cells were incubated in the absence or presence of As₂O₃ at varying times and concentrations as indicated. Equal amounts of total cell lysates were resolved by SDS-PAGE and immunoblotted with an anti-phospho-TAO2 (Ser181) antibody (top) or an anti-phospho-TAK1 (Ser412) antibody (middle). The same blot was reprobed with an anti-GAPDH antibody to control for protein loading (bottom).