Fig. 5. Kinetics of rTGF-ß1 activation of p38, ERK1/2 and JNK MAPK in myofibroblasts. Western analysis of lysates from myofibroblasts that had been treated with rTGF-ß1 for different times (h=hours) and probed for the phosphorylated forms of p38MAPK (p38MAPK-P), ERK1/2 (ERK-P), and the JNK substrate Jun, mainly phosphorylated ser63 or ser73 (Jun-P63 and Jun-P73). Blots were stripped and re-probed for total amounts of p38MAPK, ERK1/2 and Jun and tubulin. The relative intensity of total ERK1/2, Jun and p38MAPK was normalized to tubulin levels. Consequently, the relative intensity of phosphorylated forms of ERK1/2, Jun and p38MAPK was normalized to total values of ERK, Jun and p38MAPK.