Figure 3. Nbs1 is required for Brca1 recruitment to the DSB site.
(A) Reciprocal co-immunoprecipitation of Brca1 and NBS1 in either untreated MCF7 cells or in MCF7 cells 30 min following 10 Gy IR. Normal rabbit IgG was used as control. ChIP of (B) Brca1 and (C) RAP80 in MCF7 cells expressing ddI-PpoI as described in Figure 1. Cells were transfected with either non-targeting control siRNA or NBS1 targeting siRNA.