| 1. |
- Matic, S., et al.
(författare)
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Mice lacking the mitochondrial exonuclease MGME1 accumulate mtDNA deletions without developing progeria
- 2018
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Replication of mammalian mitochondrial DNA (mtDNA) is an essential process that requires high fidelity and control at multiple levels to ensure proper mitochondrial function. Mutations in the mitochondrial genome maintenance exonuclease 1 (MGME1) gene were recently reported in mitochondrial disease patients. Here, to study disease pathophysiology, we generated Mgme1 knockout mice and report that homozygous knockouts develop depletion and multiple deletions of mtDNA. The mtDNA replication stalling phenotypes vary dramatically in different tissues of Mgme1 knockout mice. Mice with MGME1 deficiency accumulate a long linear subgenomic mtDNA species, similar to the one found in mtDNA mutator mice, but do not develop progeria. This finding resolves a long-standing debate by showing that point mutations of mtDNA are the main cause of progeria in mtDNA mutator mice. We also propose a role for MGME1 in the regulation of replication and transcription termination at the end of the control region of mtDNA.
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| 2. |
- Lee, Richard G., et al.
(författare)
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Early-onset Parkinson disease caused by a mutation in CHCHD2 and mitochondrial dysfunction
- 2018
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Ingår i: Neurology Genetics. - : Wolters Kluwer. - 2376-7839. ; 4:5
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Tidskriftsartikel (refereegranskat)abstract
- Objective Our goal was to identify the gene(s) associated with an early-onset form of Parkinson disease (PD) and the molecular defects associated with this mutation. Methods We combined whole-exome sequencing and functional genomics to identify the genes associated with early-onset PD. We used fluorescence microscopy, cell, and mitochondrial biology measurements to identify the molecular defects resulting from the identified mutation. Results Here, we report an association of a homozygous variant in CHCHD2, encoding coiled-coil-helix-coiled-coil-helix domain containing protein 2, a mitochondrial protein of unknown function, with an early-onset form of PD in a 26-year-old Caucasian woman. The CHCHD2 mutation in PD patient fibroblasts causes fragmentation of the mitochondrial reticular morphology and results in reduced oxidative phosphorylation at complex I and complex IV. Although patient cells could maintain a proton motive force, reactive oxygen species production was increased, which correlated with an increased metabolic rate. Conclusions Our findings implicate CHCHD2 in the pathogenesis of recessive early-onset PD, expanding the repertoire of mitochondrial proteins that play a direct role in this disease.
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