Base excision repair of DNA in mammalian cells

Base excision repair (BFR) of DNA corrects a number of spontaneous and envi ronmentally induced genotoxic or miscoding base lesions in a process initia ted by DNA glycosylases. An AP endonuclease cleaves at the 5' side of the a basic site and the repair process is subsequently completed via either shor t patch repair or long patch repair, which largely require different protei ns. As one example, the UNG gene encodes both nuclear (UNG2) and mitochondr ial (UNG1) uracil DNA glycosylase and prevents accumulation of uracil in th e genome. BER is likely to have a major role in preserving the integrity of DNA during evolution and may prevent cancer. (C) 2000 Federation of Europe an Biochemical Societies. Published by Elsevier Science B,V. All rights res erved.