Figure 4

SFK inhibition blocks the phosphorylation of ERK and AKT. (Panel A) Four B lymphoma cells were treated with or without the indicated amount of PP2 for 1 hr. The cell lysates were analyzed by Western blotting for p-ERK. The blot was stripped and re-probed for total ERK. (B) Four B lymphoma cells lines were treated with or without PP2 for 1 hr. The cell lysates were analyzed by Western blotting for p-JNK. The blots were stripped and re-probed for β-actin. The ODs for p-JNK were normalized to the corresponding β-actin bands. For each cell line, the ODs are depicted as a fold change over no PP2. (C) BKS-2 and Ly10 lymphoma cells were treated with or without the indicated amount of PP1 or PP2 for 1 hr. As a positive control, normal splenic B cells were treated with 20 μg/ml anti-IgM for 15 min. The cell lysates were analyzed by Western blotting for p-AKT. The blot was stripped and re-probed for total AKT. The ODs for p-AKT were normalized to the corresponding bands for total AKT. For each cell type, the ODs are depicted as a fold change over no anti-IgM or PP2.