DNA Polymerases α and β Are Required for DNA Repair in an Efficient Nuclear Extract from Xenopus Oocytes

• Published in: The Journal of biological chemistry 1996-06, Vol.271 (23), p.13816
• Main Authors: Naoko Oda, Jitendra K. Saxena, Timothy M. Jenkins, Rajendra Prasad, Samuel H. Wilson, Eric J. Ackerman
• Format: Article
• Language: English
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.271.23.13816

Xenopus oocytes and an oocyte nuclear extract efficiently repair the bulky DNA lesions cyclobutane pyrimidine dimers, (6-4) photoproducts, and N -acetoxy-2-aminofluorene (AAF) adducts by an excision repair mechanism. Nearly all (>95%) of the input damaged DNA was repaired within 5 h in both injected cells and extracts with no significant incorporation of label into control undamaged DNA. Remarkably, more than 10 10 cyclobutane pyrimidine dimers or (6-4) photoproducts are repaired/nuclei. The extracts are free from nuclease activity, and repair is independent of exogenous light. Both the high efficiency and DNA polymerase requirements of this system appear to be different from extracts derived from human cells. We demonstrated a requirement for DNA polymerases α and β in repair of both photoproducts and AAF by inhibiting repair with several independent antibodies specific to either DNA polymerases α or β and then restoring repair by adding the appropriate purified polymerase. Repair is inhibited by aphidicolin at concentrations specific for blocking DNA polymerase α and dideoxynucleotide triphosphates at concentrations specific for inhibiting DNA polymerase β.