Modeling pathogenic mutations of human twinkle in Drosophila suggests an apoptosis role in response to mitochondrial defects
Language: 
English
Abstract: 

The human gene C10orf2 encodes the mitochondrial replicative DNA helicase Twinkle, mutations of which are responsible for a significant fraction of cases of autosomal dominant progressive external ophthalmoplegia (adPEO), a human mitochondrial disease caused by defects in intergenomic communication. We report the analysis of orthologous mutations in the Drosophila melanogaster mitochondrial DNA (mtDNA) helicase gene, d-mtDNA helicase. Increased expression of wild type d-mtDNA helicase using the UAS-GAL4 system leads to an increase in mtDNA copy number throughout adult life without any noteworthy phenotype, whereas overexpression of d-mtDNA helicase containing the K388A mutation in the helicase active site results in a severe depletion of mtDNA and a lethal phenotype. Overexpression of two d-mtDNA helicase variants equivalent to two human adPEO mutations shows differential effects. The A442P mutation exhibits a dominant negative effect similar to that of the active site mutant. In contrast, overexpression of d-mtDNA helicase containing the W441C mutation results in a slight decrease in mtDNA copy number during the third instar larval stage, and a moderate decrease in life span in the adult population. Overexpression of d-mtDNA helicase containing either the K388A or A442P mutations causes a mitochondrial oxidative phosphorylation (OXPHOS) defect that significantly reduces cell proliferation. The mitochondrial impairment caused by these mutations promotes apoptosis, arguing that mitochondria regulate programmed cell death in Drosophila. Our study of d-mtDNA helicase overexpression provides a tractable Drosophila model for understanding the cellular and molecular effects of human adPEO mutations.

Author(s): 
Sanchez-Martinez, Alvaro
Calleja, Manuel
Peralta, Susana
Matsushima, Yuichi
Hernandez-Sierra, Rosana
Whitworth, Alexander J.
Kaguni, Laurie S.
Garesse, Rafael
Item Type: 
Journal Article
Publication Title: 
PloS One
Journal Abbreviation: 
PLoS ONE
Publication Date: 
2012
Publication Year: 
2012
Pages: 
e43954
Volume: 
7
Issue: 
8
ISSN: 
1932-6203
DOI: 
10.1371/journal.pone.0043954
Library Catalog: 
NCBI Published Medical (?)
Extra: 
PMID: 22952820 PMCID: PMC3429445

Turabian/Chicago Citation

Alvaro Sanchez-Martinez, Manuel Calleja, Susana Peralta, Yuichi Matsushima, Rosana Hernandez-Sierra, Alexander J. Whitworth, Laurie S. Kaguni and Rafael Garesse. 2012. "Modeling pathogenic mutations of human twinkle in Drosophila suggests an apoptosis role in response to mitochondrial defects." PloS One 7: 8: e43954. 10.1371/journal.pone.0043954.

Wikipedia Citation

<ref> {{Cite journal | doi = 10.1371/journal.pone.0043954 | issn = 1932-6203 | volume = 7 | pages = e43954 | last = Sanchez-Martinez | first = Alvaro | coauthors = Calleja, Manuel, Peralta, Susana, Matsushima, Yuichi, Hernandez-Sierra, Rosana, Whitworth, Alexander J., Kaguni, Laurie S., Garesse, Rafael | title = Modeling pathogenic mutations of human twinkle in Drosophila suggests an apoptosis role in response to mitochondrial defects | journal = PloS One | date = 2012 | pmid = | pmc = }} </ref>