Figure 2.

ERK-dependent phosphorylation of BIS following H₂O₂ treatment. Expression of indicated proteins was analyzed by western blotting, with β-actin serving as a loading control. (a) A172 cells were treated with 100 μM H₂O₂ for 3 h, after which cells were lysed, and alkaline phosphatase (0.5 U) was added to cell lysates, which were incubated at 37 °C for 30 min. (b) A172 cells were treated with U0126 (ERK inhibitor), SB203580 (p38 inhibitor), or SP600125 (JNK inhibitor) for 1 h prior to addition of 100 μM H₂O₂. After 3 h, total protein was extracted and BIS expression was determined by western blotting. (c) Activation of ERK, p38, and JNK was suppressed by their respective inhibitors, as determined by western blotting. BIS, B-cell lymphoma (BCL)-2-interacting cell death suppressor; ERK, extracellular signaling-regulated kinase; JNK, c-Jun N-terminal kinase.