FAM135B: a new player in DNA damage response

The ATM (Ataxia telangiectasia mutated) kinase and its complex with TIP60 could rapidly respond to DNA double-strand breaks. But the molecular mechanism remains elusive. New research identifies FAM135B as a novel regulator of TIP60-ATM axis. FAM135B interacts with and maintains the TIP60-ATM reservoir in resting condition, whereas it dissociates from the complex and degrades, allowing cells to respond to DNA damage. This work reveals a direct link between the steady-state organization of ATM and the kinetics of its activation after DNA damage.