Fig 4.

Induction of p38δ expression by the Ras–Raf-1–MEK pathway. (A) Western blot analysis of the p38δ protein levels in BJ cells on day 8 after transduction of Ha-rasV12 (Ras), the constitutively active forms of the indicated Ras downstream effectors, or vector controls (BP or WN). Numbers represent relative levels of the protein. (B) Analysis of the p38δ mRNA levels by quantitative real-time RT-PCR in BJ cells on day 8 after transduction of Ha-rasV12 (Ras), the constitutively active forms of the indicated Ras downstream effectors, or vector controls (BP or WN). Signals for p38δ mRNA were normalized first to that of PBGD and then to that from cells transduced with vector control (BP or WN). Values are means ± SDs for triplicates. *, P < 0.05 versus BP or WN by Student's t test.