Format

Send to

Choose Destination
J Cell Sci. 2018 Jul 4;131(13). pii: jcs217075. doi: 10.1242/jcs.217075.

ATAD3 controls mitochondrial cristae structure in mouse muscle, influencing mtDNA replication and cholesterol levels.

Author information

1
Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
2
Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu 80101, Finland.
3
Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
4
Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA.
5
Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA cmoraes@med.miami.edu.
6
Department of Cell Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.

Abstract

Mutations in the mitochondrial inner membrane ATPase ATAD3A result in neurological syndromes in humans. In mice, the ubiquitous disruption of Atad3 (also known as Atad3a) was embryonic lethal, but a skeletal muscle-specific conditional knockout (KO) was viable. At birth, ATAD3 muscle KO mice had normal weight, but from 2 months onwards they showed progressive motor-impaired coordination and weakness. Loss of ATAD3 caused early and severe mitochondrial structural abnormalities, mitochondrial proliferation and muscle atrophy. There was dramatic reduction in mitochondrial cristae junctions and overall cristae morphology. The lack of mitochondrial cristae was accompanied by a reduction in high molecular weight mitochondrial contact site and cristae organizing system (MICOS) complexes, and to a lesser extent in OPA1. Moreover, muscles lacking ATAD3 showed altered cholesterol metabolism, accumulation of mitochondrial DNA (mtDNA) replication intermediates, progressive mtDNA depletion and deletions. Unexpectedly, decreases in the levels of some OXPHOS components occurred after cristae destabilization, indicating that ATAD3 is not crucial for mitochondrial translation, as previously suggested. Our results show a critical early role of ATAD3 in regulating mitochondrial inner membrane structure, leading to secondary defects in mtDNA replication and complex V and cholesterol levels in postmitotic tissue.This article has an associated First Person interview with the first author of the paper.

KEYWORDS:

ATAD3; Cholesterol; Cristae; MICOS complex; Mitochondria; Muscle

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center