Format

Send to

Choose Destination
PLoS Biol. 2012;10(3):e1001288. doi: 10.1371/journal.pbio.1001288. Epub 2012 Mar 20.

Mutations in the mitochondrial methionyl-tRNA synthetase cause a neurodegenerative phenotype in flies and a recessive ataxia (ARSAL) in humans.

Author information

1
Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America.

Abstract

An increasing number of genes required for mitochondrial biogenesis, dynamics, or function have been found to be mutated in metabolic disorders and neurological diseases such as Leigh Syndrome. In a forward genetic screen to identify genes required for neuronal function and survival in Drosophila photoreceptor neurons, we have identified mutations in the mitochondrial methionyl-tRNA synthetase, Aats-met, the homologue of human MARS2. The fly mutants exhibit age-dependent degeneration of photoreceptors, shortened lifespan, and reduced cell proliferation in epithelial tissues. We further observed that these mutants display defects in oxidative phosphorylation, increased Reactive Oxygen Species (ROS), and an upregulated mitochondrial Unfolded Protein Response. With the aid of this knowledge, we identified MARS2 to be mutated in Autosomal Recessive Spastic Ataxia with Leukoencephalopathy (ARSAL) patients. We uncovered complex rearrangements in the MARS2 gene in all ARSAL patients. Analysis of patient cells revealed decreased levels of MARS2 protein and a reduced rate of mitochondrial protein synthesis. Patient cells also exhibited reduced Complex I activity, increased ROS, and a slower cell proliferation rate, similar to Drosophila Aats-met mutants.

PMID:
22448145
PMCID:
PMC3308940
DOI:
10.1371/journal.pbio.1001288
[Indexed for MEDLINE]
Free PMC Article

Conflict of interest statement

The authors have declared that no competing interests exist.

Supplemental Content

Full text links

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