Ataxin-3 protein modification as a treatment strategy for Spinocerebellar Ataxia type 3: Removal of the CAG containing exon

Publication Type:

Journal Article

Source:

Neurobiology of disease (2013)

ISBN:

1095-953X (Electronic)09

DOI Name (links to online publication)

10.1016/j.nbd.2013.04.019

Abstract:

Spinocerebellar ataxia type 3 is caused by a polyglutamine expansion in the ataxin-3 protein, resulting in gain of toxic function of the mutant protein. The expanded glutamine stretch in the protein is the result of a CAG triplet repeat expansion in the penultimate exon of the ATXN3 gene. Several gene silencing approaches to reduce mutant ataxin-3 toxicity in this disease aim to lower ataxin-3 protein levels, but since this protein is involved in deubiquitination and proteasomal protein degradation, its long-term silencing might not be desirable. Here, we propose a novel protein modification approach to reduce mutant ataxin-3 toxicity by removing the toxic polyglutamine repeat from the ataxin-3 protein through antisense oligonucleotide-mediated exon skipping while maintaining important wild type functions of the protein. In vitro studies showed that exon skipping did not negatively impact the ubiquitin binding capacity of ataxin-3. Our in vivo studies showed no toxic properties of the novel truncated ataxin-3 protein. These results suggest exon skipping may be a novel therapeutic approach to reduce polyglutamine-induced toxicity in spinocerebellar ataxia type 3.

16/05/2013