Enforced bcl-2 prevents the selective downmodulation of NF-κB DNA binding by Dex. Effect of Dex on (A) NF-κB and (B) octamer binding protein (Oct-1) DNA binding activities in parental and bcl-2 ARP-1 transfectants. (A) NEs from parental and bcl-2 ARP-1 transfectants treated with and without Dex (0.1 μmol/L) for 24 hours were incubated with a ³²P-labeled probe containing the κB binding site of the IL-6 promoter and assayed by EMSA. (B) The same NEs used in (A) were tested for Oct-1 DNA binding by EMSA using a radiolabeled Oct-1 probe containing a consensus binding site for Oct family homeodomain TFs. Arrows indicate two distinct NF-κB complexes in (A) and four Oct-1 complexes in (B).