importantly, we demonstrate that heterochromatic dsbs are generally repaired more slowly than euchromatic dsbs and that atm-signalling is specifically required for dsb-repair within heterochromatin.
Knockdown of the transcriptional repressor KAP-1, an ATM substrate, or the heterochromatin- building factors HP1 or HDAC1/2 alleviates the requirement for ATM in DSB- repair.