FIG. 3.

EGFR1 and EGFRvIII differentially activate MAPKs to induce TBP promoter activity. (A) EGFR1 and EGFRvIII differentially activate ERK1/2 and JNK1/2. Immunoblot analysis was performed using whole cell lysates derived from serum-deprived U87 or NR6 stable cell lines using antibodies against p38, ERK, and JNK as well as phospho-specific antibodies. (B) EGFR1 and EGFRvIII require activation of all three classes of MAPKs to induce TBP promoter activity. U87 stable cell lines were transfected with the wild-type TBP promoter-luciferase construct. Cells were treated as described in Materials and Methods with inhibitors for ERK1/2 (U0126), p38 (SP600125), or JNK1/2 (SB202190) and analyzed for luciferase activity. The change was calculated based on normalization to untreated cells.