Figure 4.
Chromatin and nuclear positioning contribute to DSB repair pathway choice. H3K36Me3 and acetylated histones are present in transcriptionally-active regions. These marks promote use of HR for repair of DSBs by LEDGF-mediated recruitment of CtIP and ZMYND8-mediated recruitment of the NuRD complex, which remodels nucleosomes. The presence of macro-H2A also correlates with increased use of HR. Heterochromatic regions of the genome, particularly pericentromeric heterochromatin, are preferentially repaired by HR. Conversely, DSBs that occur near the nuclear periphery show increased repair by NHEJ. See text for details.