Fig. 8.

Posttranslational modifications regulate E2F1 recruitment and function at DSBs.  E2F1 phosphorylation recruits E2F1 and RB to sites of DNA damage via an interaction with TopBP1, while E2F1 acetylation creates a binding motif for the bromodomains of p300 and CBP allowing E2F1 and RB to direct p300/CBP-mediated H3 acetylation in chromatin flanking DSBs. E2F1 phosphorylation and acetylation are also important for the recruitment of Tip60 and BRG1 to sites of DNA damage and for loading of the MRN complex