Fig. 7.

Arginines 196–198 in the KLF6 5′ basic region are critical for NC-XRE binding. (A) Wild-type hKLF6 and a mutant protein with three consecutive arginine residues (Arg196–198) replaced by alanines (hKLF6-AAA) were expressed along with the hAhR in vitro using the TnT expression system. (A) Recombinant proteins were treated with vehicle (-) or 20 nM TCDD (+) for 20 minutes at 37°C and subjected to coimmunoprecipitation using the anti-AhR antibody. Coprecipitation of hKLF6 was evaluated by SDS-PAGE and Western blotting using an anti-KLF6 antibody. (B) EMSA was performed using the recombinant proteins and ³²P-radiolabeled NC-XRE, and complex formation visualized by autoradiography (arrows). IP, immunoprecipitation.