FIG. 4.
Wortmannin preferentially inhibits UV-driven activation of JNK1. (A) Logarithmically growing NIH 3T3 cells were not treated (Control) or pretreated for 30 min with the indicated concentration of wortmannin (Wort; 2 to 200 nM). Thereafter, cells were either UV irradiated (40 J/m2) or treated with MMS (1 mM). After a further incubation period of 30 min (for UV irradiation) and 60 min (for MMS) in the presence of the corresponding concentration of wortmannin, cells were harvested for determination of JNK1 activity. Shown are the autoradiograms. (B) Quantitative densitometric analysis of the autoradiograms shown in panel A. (C) Statistical analysis of the inhibitory effect of wortmannin on JNK1 activation by UV irradiation and MMS treatment, respectively. Data shown are mean values ± standard deviations from five (UV) and four (MMS) independent experiments, respectively. ∗, P < 0.01.