Format

Send to

Choose Destination
PLoS Genet. 2016 Dec 2;12(12):e1006463. doi: 10.1371/journal.pgen.1006463. eCollection 2016 Dec.

The Mitochondrial m-AAA Protease Prevents Demyelination and Hair Greying.

Author information

1
Institute for Genetics, University of Cologne, Cologne, Germany.
2
Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.
3
Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany.
4
Department of Dermatology, University of Cologne, Cologne, Germany.

Abstract

The m-AAA protease preserves proteostasis of the inner mitochondrial membrane. It ensures a functional respiratory chain, by controlling the turnover of respiratory complex subunits and allowing mitochondrial translation, but other functions in mitochondria are conceivable. Mutations in genes encoding subunits of the m-AAA protease have been linked to various neurodegenerative diseases in humans, such as hereditary spastic paraplegia and spinocerebellar ataxia. While essential functions of the m-AAA protease for neuronal survival have been established, its role in adult glial cells remains enigmatic. Here, we show that deletion of the highly expressed subunit AFG3L2 in mature mouse oligodendrocytes provokes early-on mitochondrial fragmentation and swelling, as previously shown in neurons, but causes only late-onset motor defects and myelin abnormalities. In contrast, total ablation of the m-AAA protease, by deleting both Afg3l2 and its paralogue Afg3l1, triggers progressive motor dysfunction and demyelination, owing to rapid oligodendrocyte cell death. Surprisingly, the mice showed premature hair greying, caused by progressive loss of melanoblasts that share a common developmental origin with Schwann cells and are targeted in our experiments. Thus, while both neurons and glial cells are dependant on the m-AAA protease for survival in vivo, complete ablation of the complex is necessary to trigger death of oligodendrocytes, hinting to cell-autonomous thresholds of vulnerability to m-AAA protease deficiency.

PMID:
27911893
PMCID:
PMC5135034
DOI:
10.1371/journal.pgen.1006463
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Public Library of Science Icon for PubMed Central
Loading ...
Support Center