Plays a key role in the repair of DNA damage, functioning as part of both the non-homologous end-joining (NHEJ) and base excision repair (BER) pathways (  ). Through its two catalytic activities, PNK ensures that DNA termini are compatible with extension and ligation by either removing 3'-phosphates from, or by phosphorylating 5'-hydroxyl groups on, the ribose sugar of the DNA backbone (, ).
Subcellular locations: Nucleus, Chromosome
Localizes to site of double-strand breaks.
Expressed in many tissues with highest expression in spleen and testis, and lowest expression in small intestine . Expressed in higher amount in pancreas, heart and kidney and at lower levels in brain, lung and liver .