FIG. 1.

Stable LMP1 expression induces the constitutive activation of ERK1/2 in LMP1-expressing epithelial cell lines. (A to C) Immunoblot analyses demonstrating the expression of p-ERK1/2 (upper panels), total ERK1/2 (middle panels), and LMP1 (lower panels) in control and LMP-expressing cells in the presence (+ U0126) or absence (untreated) of the MEK inhibitor U0126. Representative analyses for SCC12F (A), Rhek-1 (B), and MDCK (C) cells are shown. (D) Rhek-1, SCC12F, and MDCK cells stimulated with EGF (+) or left untreated (−) were included as a positive control. The increases (n-fold) in ERK-MAPK phosphorylation are indicated in parentheses. Numbers on the left of the blots are molecular weight markers. p-p44, phosphorylated p44; p-p42, phosphorylated p42.