Perspectives on PARPs in S Phase

PARP1 and PARP2 are essential for embryonic viability, and chemical inhibition of these enzymes in the clinic selectively kills homologous recombination-defective cancer cells (e.g., those harbouring mutations in BRCA1 or BRCA2). PARP1 and PARP2 are activated by potentially pathogenic nucleic acid structures such as DNA breaks, DNA single-strand gaps, and stalled or broken DNA replication forks. PARP activity signals the presence of these...