FIG. 3.

EMSAs with DNA containing the GADD45 WT1-EGR1 site. (A) Nuclear extracts from H1299 or MCF-7 cells, which were prepared from untreated cells (Control) or cells 4 h after treatment with MMS or UV radiation, were incubated with a labeled 30-bp probe corresponding to this region (intact sequence) or to one containing mutated WT1-EGR1 sites (mutated sequence) as described in Materials and Methods. (B) EMSA was carried out in the same manner except that extracts were immunodepleted prior to analysis with preimmune serum (PI); antibody (Ab) against WT1 (WTc8), Egr1 (NGF-1), or p53 (PAB421; Oncogene Science); or nonspecific IgG prior to analysis. Control, no immunodepletion. (C) EMSA was carried out as for panel A, but with a 20- or 50-fold excess of either the wt (SELF) or the same mutated sequence (MUTANT) as in A. Probe, no nuclear extract. The arrows indicate specific bands in MCF-7 cell extract.