Figure 1.

MKK4 gene disruption does not affect MAPK activation in response to cross-linking of FcɛRI or to KL and IL-3 in ESMCs. MKK4+/+ and MKK4−/− ESMC (3 × 10⁶ cells) sensitized with anti-OVA IgE were stimulated by the addition of 10 μg/ml OVA. JNK activity was measured 15 min after the addition of OVA. Activities of p38 and ERK2 were measured 5 min after the addition of OVA. ESMCs were deprived of KL and IL-3 from culture medium for 3 h and stimulated with 100 ng/ml KL or 50 ng/ml IL-3. JNK activities were measured 15 min after the addition of KL or IL-3. p38 and ERK2 activities were measured 5 min after the addition of KL or IL-3. Representative autoradiographs from three independent experiments are shown.