Mechanisms of DNA repair in mitochondria

Abstract

The role of mitochondria in cellular metabolism and functioning can hardly be overestimated. Mitochondria carry out many functions, and their main function is the production of ATP, the energetic “currency” of the cell. Mitochondria possess a small circular DNA, which codes for 13 proteins. Mitochondrial DNA, or mtDNA, as well as the nuclear one, is subjected to the influence of environmental and endogenous factors. This may lead to mtDNA damage. Here we review the data on mtDNA damage and repair mechanisms. The functioning of mitochondria directly depends on integrity of mtDNA, and therefore, on correct functioning of the mtDNA repair system. These systems differ from the repair systems of nuclear DNA and are in general understudied. The existence of excision nucleotides repair system correcting bulky lesions in mitochondria is still under question. Specific degradation of damaged mtDNA can probably serve as an alternative way to prevent the accumulation of bulky lesions. A search for new pathways of mtDNA repair is of considerable interest.