title: Single-Molecule Analysis of mtDNA Replication Uncovers the Basis of the Common Deletion.
abstract: Mutations in mtDNA lead to muscular and neurological diseases and are linked to aging. The most frequent aberrancy is the "common deletion" that involves a 4,977-bp region flanked by 13-bp repeats. To investigate the basis of this deletion, we developed a single-molecule mtDNA combing method. The analysis of replicating mtDNA molecules provided in vivo evidence in support of the asymmetric mode of replication. Furthermore, we observed frequent fork stalling at the junction of the common deletion, suggesting that impaired replication triggers the formation of this toxic lesion. In parallel experiments, we employed mito-TALENs to induce breaks in distinct loci of the mitochondrial genome and found that breaks adjacent to the 5' repeat trigger the common deletion. Interestingly, this process was mediated by the mitochondrial replisome independent of canonical DSB repair. Altogether, our data underscore a unique replication-dependent repair pathway that leads to the mitochondrial common deletion.
authors.affiliation: Skirball Institute of Biomolecular Medicine, Department of Cell Biology, NYU School of Medicine, New York, NY 10016, USA.
authors.forename: Aaron F
authors.initials: AF
authors.lastname: Phillips
authors.affiliation: Structure et Instabilité des Génomes, Muséum National d'Histoire Naturelle, INSERM U 1154, CNRS UMR 7196, 75005 Paris, France; Genome Dynamics in the Immune System Laboratory, INSERM, UMR 1163, Institut Imagine, 75015 Paris, France.
authors.forename: Armêl R
authors.initials: AR
authors.lastname: Millet
authors.affiliation: Skirball Institute of Biomolecular Medicine, Department of Cell Biology, NYU School of Medicine, New York, NY 10016, USA.
authors.forename: Marco
authors.initials: M
authors.lastname: Tigano
authors.affiliation: Structure et Instabilité des Génomes, Muséum National d'Histoire Naturelle, INSERM U 1154, CNRS UMR 7196, 75005 Paris, France.
authors.forename: Sonia M
authors.initials: SM
authors.lastname: Dubois
authors.affiliation: Skirball Institute of Biomolecular Medicine, Department of Cell Biology, NYU School of Medicine, New York, NY 10016, USA.
authors.forename: Hannah
authors.initials: H
authors.lastname: Crimmins
authors.affiliation: Structure et Instabilité des Génomes, Muséum National d'Histoire Naturelle, INSERM U 1154, CNRS UMR 7196, 75005 Paris, France; Genome Dynamics in the Immune System Laboratory, INSERM, UMR 1163, Institut Imagine, 75015 Paris, France.
authors.forename: Loelia
authors.initials: L
authors.lastname: Babin
authors.affiliation: Structure et Instabilité des Génomes, Muséum National d'Histoire Naturelle, INSERM U 1154, CNRS UMR 7196, 75005 Paris, France.
authors.forename: Marine
authors.initials: M
authors.lastname: Charpentier
authors.affiliation: Structure et Instabilité des Génomes, Muséum National d'Histoire Naturelle, INSERM U 1154, CNRS UMR 7196, 75005 Paris, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Piganeau
authors.affiliation: Structure et Instabilité des Génomes, Muséum National d'Histoire Naturelle, INSERM U 1154, CNRS UMR 7196, 75005 Paris, France; Genome Dynamics in the Immune System Laboratory, INSERM, UMR 1163, Institut Imagine, 75015 Paris, France. Electronic address: erika.brunet@inserm.fr.
authors.forename: Erika
authors.initials: E
authors.lastname: Brunet
authors.affiliation: Skirball Institute of Biomolecular Medicine, Department of Cell Biology, NYU School of Medicine, New York, NY 10016, USA. Electronic address: agnel.sfeir@med.nyu.edu.
authors.forename: Agnel
authors.initials: A
authors.lastname: Sfeir
mesh_terms: D000375:Aging / Q000235:genetics; D004265:DNA Helicases / Q000235:genetics; D004261:DNA Replication; D004272:DNA, Mitochondrial / Q000378:metabolism*; D006801:Humans; D008928:Mitochondria / Q000235:genetics; D024101:Mitochondrial Proteins / Q000235:genetics; D017384:Sequence Deletion; D000072760:Single Molecule Imaging / Q000379:methods*; D000069896:Transcription Activator-Like Effector Nucleases / Q000378:metabolism
chemical_list: D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins; D000069896:Transcription Activator-Like Effector Nucleases; D004265:DNA Helicases; C431576:TWNK protein, human
keywords: common deletion; microhomology-mediated end joining; mito-SMARD; mito-TALEN; mtDNA; repair; replication