Figure 4.

IRIF formation of RAP80, CCDC98, BRCC36, BRE, and MERIT40 requires all four other components in this protein complex. (A,C–E) U2OS cells or 293T cells stably expressing SFB-tagged BRE (B) were transfected with control siRNAs or siRNAs specifically targeting indicated genes. Cells were irradiated, fixed, and immunostained with anti-MERIT40 (A), anti-Flag (BRE) (B), anti-BRCC36 (C), anti-RAP80 (D), or anti-CCDC98 (E) antibodies with or without costaining with anti-γH2AX antibodies. More than 200 cells were counted to determine the percentages of foci-forming cells in each sample.