Ataxia telangiectasia mutated (ATM) is a serine/threonine protein kinase that plays a central role in DNA damage response (DDR). It can be active in the absence of DDR and in response to oxidative stress in mitochondria. ATM induces signaling and initiation of cell cycle checkpoint signaling in response to DNA-damaging agents, such as ionizing radiation. It may be associated with pancreatic cancers. ATM inhibition is found to induce mimosine-arrested cells to enter S phase and is associated with preventation of replication fork stalling-induced DNA damage.
