FIG. 10.
Activation of MEK-ERK precedes the activation of MKK3/6-p38 and premature senescence. The levels of Ha-Ras, phospho-MEK1 and 2 (P-MEK1/2), phospho-ERK1 and 2 (P-ERK1/2), ERK2, phospho-p38 (P-p38), p38, phospho-MKK3 and 6 (P-MKK3/6), p16INK4A, and actin were determined by Western blotting after different days (days 3 to 9) following the transduction of BJ cells at PD 35 with a vector control (V) or Ha-RasV12 (R). The percentages of cells positive for SA-β-gal within these same cell populations are shown at the bottom.