Figure 1: Nuclear and mitochondrial DNA repair mechanisms. DNA repair lesions are represented in red and DNA repair mechanisms are coded with specific colors. Only the central proteins involved in each pathway are represented. Enzymes involved in mitochondrial DNA repair are in some cases splice variants of the corresponding nuclear DNA repair enzymes. More detailed information about the different pathways is included in the text. BER: base excision repair; NER: nucleotide excision repair; MMR: mismatch repair; HRR: homologous recombinational repair; NHEJ: nonhomologous end joining; ETC: electron transport chain; ROS: reactive oxygen species.