Mitochondrial DNA repair pathways

DNA repair mechanisms are fairly well characterized for nuclear DNA while k nowledge regarding the repair mechanisms operable in mitochondria is limite d. Several lines of evidence suggest that mitochondria contain DNA repair m echanisms. DNA lesions are removed from mtDNA in cells exposed to various c hemicals. Protein activities that process damaged DNA have been detected in mitochondria. As will be discussed, there is evidence for base excision re pair (BER), direct damage reversal, mismatch repair, and recombinational re pair mechanisms in mitochondria, while nucleotide excision repair (NER), as we know it from nuclear repair, is not present. (C) 1999 Elsevier Science B.V. All rights reserved.