Chromosomal single-strand break repair

Abstract

Tens of thousands of cellular single strand breaks (SSBs) arise in cells each day, from attack of deoxyribose and DNA bases by reactive oxygen species and other electrophilic molecules, and from the intrinsic instability of DNA. If not repaired, SSBs can block transcription and replication and can be converted into potentially clastogenic and/or lethal DNA double-strand breaks. SSBs can arise directly by disintegration of damaged deoxyribose, and indirectly as normal intermediates of DNA base excision repair (BER). Here, the molecular mechanism/s and organisation of the DNA repair pathways that remove single strand breaks are reviewed and the connection between defects in these pathways and hereditary neurodegenerative disease are discussed. © 2009 Springer Science+Business Media B.V.