Figure 4

IL-1β causes ERK-dependent phosphorylation of Elk-1 on ZC3H12A promoter. A, Activation of Elk-1 after IL-1β stimulation. HepG2 cells were stimulated by IL-1β (15 ng/ml) for 5, 10 and 15 min and the phosphorylation of Elk-1 was analyzed by western blot analysis. To some experimental groups U0126 (10 μM) was added 30 min prior IL-1β stimulation (lanes 5-8). Asterisks indicate unspecific bands. B, Chromatin immunoprecipitation of the phosphorylated Elk-1 bound to the ZC3H12A promoter. HepG2 cells were incubated in 0.5% FCS medium for 12 hrs and then stimulated for 15, 30 or 90 min with IL-1β. The antibodies anti-P-Elk were used to immunoprecipitate sonicated chromatin. As a negative control non-specific IgG were employed. Eluted DNA served as a template in PCR analysis with oligonucleotides specific for ZC3H12A promoter. 1% of input DNA is shown in lines 9-12. The panels show the inverted images of ethidium bromide-stained gels.