Base Excision Repair and its Role in Maintaining Genome Stability

Abstract

For all living organisms, genome stability is important, but is also under constant threat because various environmental and endogenous damaging agents can modify the structural properties of DNA bases. As a defense, organisms have developed different DNA repair pathways. Base excision repair (BER) is the predominant pathway for coping with a broad range of small lesions resulting from oxidation, alkylation, and deamination, which modify individual bases without large effect on the double helix structure. As, in mammalian cells, this damage is estimated to account daily for 10⁴ events per cell, the need for BER pathways is unquestionable. The damage-specific removal is carried out by a considerable group of enzymes, designated as DNA glycosylases. Each DNA glycosylase has its unique specificity and many of them are ubiquitous in microorganisms, mammals, and plants. Here, we review the importance of the BER pathway and we focus on the different roles of DNA glycosylases in various organisms.

Keywords:

• DNA glycosylase
• DNA repair
• DNA damage
• mutagenesis

ACKNOWLEDGEMENTS

We are grateful to Geert Angenon for critical reading of the manuscript and for suggestions and Martine De Cock for help in preparing the manuscript. J.B. was indebted to the Institute for the Promotion of Innovation by Science and Technology in Flanders for a predoctoral fellowship.

Editor: Michael M. Cox