Ultrasensitive deletion detection links mitochondrial DNA replication, disease, and aging

BACKGROUND: Acquired human mitochondrial genome (mtDNA) deletions are symptoms and drivers of focal mitochondrial respiratory deficiency, a pathological hallmark of aging and late-onset mitochondrial disease.

RESULTS: To decipher connections between these processes, we create LostArc, an ultrasensitive method for quantifying deletions in circular mtDNA molecules. LostArc reveals 35 million deletions (~ 470,000 unique spans) in skeletal muscle from 22 individuals with and 19 individuals without pathogenic variants in POLG. This nuclear gene encodes the catalytic subunit of replicative mitochondrial DNA polymerase γ. Ablation, the deleted mtDNA fraction, suffices to explain skeletal muscle phenotypes of aging and POLG-derived disease. Unsupervised bioinformatic analyses reveal distinct age- and disease-correlated deletion patterns.

CONCLUSIONS: These patterns implicate replication by DNA polymerase γ as the deletion driver and suggest little purifying selection against mtDNA deletions by mitophagy in postmitotic muscle fibers. Observed deletion patterns are best modeled as mtDNA deletions initiated by replication fork stalling during strand displacement mtDNA synthesis.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:21

Enthalten in:

Genome biology - 21(2020), 1 vom: 17. Sept., Seite 248

Sprache:

Englisch

Beteiligte Personen:

Lujan, Scott A [VerfasserIn]
Longley, Matthew J [VerfasserIn]
Humble, Margaret H [VerfasserIn]
Lavender, Christopher A [VerfasserIn]
Burkholder, Adam [VerfasserIn]
Blakely, Emma L [VerfasserIn]
Alston, Charlotte L [VerfasserIn]
Gorman, Grainne S [VerfasserIn]
Turnbull, Doug M [VerfasserIn]
McFarland, Robert [VerfasserIn]
Taylor, Robert W [VerfasserIn]
Kunkel, Thomas A [VerfasserIn]
Copeland, William C [VerfasserIn]

Links:

Volltext

Themen:

DNA, Mitochondrial
DNA Polymerase gamma
EC 2.7.7.7
Evaluation Study
Journal Article
POLG protein, human
Research Support, N.I.H., Intramural
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 11.06.2021

Date Revised 11.06.2021

published: Electronic

Citation Status MEDLINE

doi:

10.1186/s13059-020-02138-5

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM315145889