Figure 3.

NONO is a chromatin-associated protein and localizes to a unique DSB in vivo. (A) Unfixed HeLa cells were treated for 1 hr with 10 µM ABT-888, washed with PBS and fractionated into chromatin-enriched, nuclear soluble and cytoplasmic fractions. Fractions were used for an analysis by western blotting. (B) Chromatin immunoprecipitation of NONO from the fixed chromatin of MCF-7 cells, which priorly had been transfected with an I-SceI coding plasmid to generate a unique DSB. An IgG antibody served as a control for the ChIP-experiment. (C) Distribution of primer pairs relative to the DSB created by I-SceI. These primers were used in q-PCR analysis of ChIP shown in (D). Primers for GAPDH served as a control for the PCR. (D) Quantification of NONO relative to the DSB by PCR (n = 3).