AP endonuclease knockdown enhances methyl methanesulfonate hypersensitivity of DNA polymerase β knockout mouse embryonic fibroblasts.

Apurinic/apyrimidinic (AP) endonuclease (Apex) is required for base excision repair (BER), which is the major mechanism of repair for small DNA lesions such as alkylated bases. Apex incises the DNA strand at an AP site to leave 3′-OH and 5′-deoxyribose phosphate (5′-dRp) termini. DNA polymerase β (PolB) plays a dominant role in single nucleotide (Sn-) BER by incorporating a nucleotide and removing...