Abstract
Purpose: :
Mutations of the OPA3 gene are associated with two diseases: Type 3-Methylglutaconic Aciduria (type III MGA) and Dominant Optic Atrophy and Cataract. Opa3 has three exons and two transcripts. To investigate the nature of the Opa3 gene and protein, we have investigated the distribution of Opa3 in both wild type and mutant mice, which carry a missense mutation; p.L122P in exon 2 of the Opa3 gene. Here we report on the transcript expression, mitochondrial localisation of the protein and tissue expression.
Methods: :
RT-PCR and qPCR of lens and tissues were used to investigate the expression of Opa3 gene; immunocytochemistry and Western blotting to study the localisation of the protein. We used a suite of bioinformatics tools to explore the upstream region of Opa3 for transcription factor binding sites (TFBS) that could be involved in Opa3 gene expression.
Results: :
The alternatively spliced second and third exons produce two transcripts which are ubiquitously expressed in all adult mouse tissues tested. Fifty three upstream transcriptional binding sites (TFBS) were identified and analysis of their functions suggest a role for Opa3 in retina, craniofacial development, cellular stress response and adipogenesis. RT-PCR demonstrates the presence of Opa3 in all tissues, and at all times studied in WT animals. Opa3 is localised to the mitochondrion by immunocytochemistry. Western blotting shows Opa3 in retina / lens lysates, and demonstrates that Opa3 levels increase as lenses age (WT), while other mitochondrial markers remain constant.
Conclusions: :
Opa3
Keywords: mitochondria • proteins encoded by disease genes • gene/expression