ATM and ATR: networking cellular responses to DNA damage

Maintenance of genome stability depends on the appropriate response to DNA damage. This response is based on complex networks of signaling pathways th at activate numerous processes and lead ultimately to damage repair and cel lular survival - or apoptosis. The protein kinases ATM and ATR are master c ontrollers of some of these networks, acting either in concert or separatel y to orchestrate the responses to specific types of DNA damage or stalled r eplication. Understanding their mode of action is essential to our understa nding of how cells cope with genotoxic stress.