DNA damage at stalled replication forks activates Chk1 kinase and poly(ADP-ribose) (PAR) polymerase 1. Min et al.find that retention of Chk1 to stalled replication forks depends on its direct interaction with PAR, and show that PAR chain length fine-tunes Chk1 and S-phase checkpoint activation.
- WooKee Min
- Christopher Bruhn
- Zhao-Qi Wang
