Sensing and responding to DNA damage

DNA damage or stalled DNA replication can activate specific signal transduc tion pathways, termed checkpoints. Checkpoint activation can result in incr eased repair, induction of a transcriptional programme and inhibition of ce ll-cycle progression. Recent results have suggested possible mechanisms for the detection of specific DNA structures, provided further information on the organisation of the signal transduction cascade and demonstrated involv ement of the checkpoint pathway in DNA repair.