Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a progressive neurodegenerative genetic disorder characterized by an early childhood onset. ARSACS presents with polyneuropathy, with hallmark loss of cerebellar Purkinje neurons, and movement disorders featuring ataxia and spasticity. The etiology of ARSACS is attributed to one of more than 200 mutations in a protein-encoding gene called sacsin. These mutations result in mutated sacsin protein molecules with aberrant functions and clinical phenotypes. To identify or design drugs that can bind to and correct the sacsin protein pathologies, the structure and function of sacsin in both native (i.e., “healthy”) and mutated (i.e., “diseased”) states need to be elucidated. However, no research has yet been published on the purification of sacsin for in vitro and structural studies. This gap in research is not intentional but is due to the large size of sacsin (520 kDa), which has hindered determination of its structure and made basic biochemical and biophysical experiments problematic. Our laboratory aims to obtain atomic resolution structure of human sacsin. In this regard, we have now established reproducible methods to purify native sacsin, imaged sacsin in electron microscopic studies, and obtained preliminary 2D structural models. Obtaining high-resolution 3D structural data is our next goal.

Grant: $100,000

Duration : one year


Dr. Walid A. Houry, Department of Biochemistry

Temerty Faculty of Medicine, University of Toronto
661 University Avenue,MaRS Centre, West Tower, Room 1612

Toronto, ON Canada M5G 1M1