Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Mitochondrial dysfunction in an Opa1Q285STOP mouse model of dominant optic atrophy results from Opa1 haploinsufficiency

Kushnareva, Y., Seong, Y., Andreyev, A. Y., Kuwana, T., Kiosses, W. B., Votruba, M. and Newmeyer, D. D. 2016. Mitochondrial dysfunction in an Opa1Q285STOP mouse model of dominant optic atrophy results from Opa1 haploinsufficiency. Cell Death and Disease 7 , e2309. 10.1038/cddis.2016.160

[img]
Preview
PDF - Accepted Post-Print Version
Download (13MB) | Preview

Abstract

Mutations in the opa1 (optic atrophy 1) gene lead to autosomal dominant optic atrophy (ADOA), a hereditary eye disease. This gene encodes the Opa1 protein, a mitochondrial dynamin-related GTPase required for mitochondrial fusion and the maintenance of normal crista structure. The majority of opa1 mutations encode truncated forms of the protein, lacking a complete GTPase domain. It is unclear whether the phenotype results from haploinsufficiency or rather a deleterious effect of truncated Opa1 protein. We studied a heterozygous Opa1 mutant mouse carrying a defective allele with a stop codon in the beginning of the GTPase domain at residue 285, a mutation that mimics human pathological mutations. Using an antibody raised against an N-terminal portion of Opa1, we found that the level of wild-type protein was decreased in the mutant mice, as predicted. However, no truncated Opa1 protein was expressed. In embryonic fibroblasts isolated from the mutant mice, this partial loss of Opa1 caused mitochondrial respiratory deficiency and a selective loss of respiratory Complex IV subunits. Furthermore, partial Opa1 deficiency resulted in a substantial resistance to endoplasmic reticulum stress-induced death. On the other hand, the enforced expression of truncated Opa1 protein in cells containing normal levels of wild-type protein did not cause mitochondrial defects. Moreover, cells expressing the truncated Opa1 protein showed reduced Bax activation in response to apoptotic stimuli. Taken together, our results exclude deleterious dominant-negative or gain-of-function mechanisms for this type of Opa1 mutation and affirm haploinsufficiency as the mechanism underlying mitochondrial dysfunction in ADOA.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Optometry and Vision Sciences
Subjects: R Medicine > RE Ophthalmology
Additional Information: Pdf uploaded in accordance with publisher's policy at http://www.sherpa.ac.uk/romeo/issn/2041-4889/ (accessed 04/05/2016)
Publisher: Springer Nature
ISSN: 2041-4889
Funders: National Institutes of Health
Date of First Compliant Deposit: 3 May 2016
Date of Acceptance: 2 May 2016
Last Modified: 17 Mar 2020 23:13
URI: http://orca-mwe.cf.ac.uk/id/eprint/90341

Actions (repository staff only)

Edit Item Edit Item

Downloads

Downloads per month over past year

View more statistics