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Functional Consequences Of Cytosine Methylation In Mitochondrial Dna Catalyzed By Dna Methyltransferase 1, Lisa Shock

Theses and Dissertations

Cytosine methylation of mitochondrial DNA (mtDNA) was first described several decades ago, but neither the mechanism generating this modification nor its functional significance was known. Because mitochondrial dysfunction is a hallmark characteristic of numerous human diseases, including neurological and cardiovascular disease, aging and cancer, this dissertation addressed whether epigenetic modification of mtDNA regulates mitochondrial function. We show that mtDNA contains not only 5-methylcytosine (5mC), but also 5-hydroxymethylcytosine (5hmC), suggesting that previous reports likely underestimated the degree of epigenetic modification within the mitochondrial genome. We questioned how these modifications were generated by looking for mitochondrial isoforms of the nuclear-encoded DNA methyltransferases. …