Identification of chromatin binding sites within IN CCD. A). 293T cells were transfected with different CMV-YFP-IN expressors (including the wild type IN and different mutants, as indicated). At 48 h post-transfection, cells were fractionated into chromatin-bound (lower panel) and non-chromatin-bound (upper panel) fractions as described in Materials and methods. YFP-IN in each fraction was analyzed by IP and WB with anti-GFP antibody. B). The intensity of both the chromatin-bound and non-chromatin-bound YFP-IN was densitometrically determined. The data are presented as the percentage of chromatin-bound YFP-IN to total input. Results are representative of two independent experiments.