抄録
Abasic (apurinc/apyrimidic, AP) sites are a major type of DNA damage. They cause cell death and mutation. They are generated spontaneously or through hydrolysis catalyzed by DNA N-glycosylases, leaving AP sites in DNA. AP endonucleases recognize and incise the DNA strand at the AP sites. The nicked DNA is filled by DNA polymerases and DNA ligases. Recently, the genome of Ciona intestinalis was deciphered. In this study, AP endonuclease in Ciona intestinalis (CiAPE) was purified and characterized. The properties of CiAPE were compared with those of human APE1. The CiAPE protein was about 34 kDa. It efficiently cleaved tetrahydrofuran (THF) - containing duplex oligonucleotides. In addition, the transformation of E. coli, BW9093Δxth with CiAPE complemented the H2O2 sensitivity. These results demonstrated that CiAPE has AP endonuclease activity to prevent against oxidative stress in Ciona intestinalis.
