The spinocerebellar ataxia type 1 protein, ataxin-1, has RNA-binding activity that is inversely affected by the length of its polyglutamine tract.

Institute of Human Genetics, Department of Laboratory Medicine and Pathology, Mayo Mail Code 206, University of Minnesota Medical School, Minneapolis, MN 55455, USA.

Spinocerebellar ataxia type 1 (SCA1) is an autosomal dominant neurodegenerative disease caused by the expansion of a polyglutamine tract within the SCA1 product, ataxin-1. Previously, using transgenic mice, it was demonstrated that in order for a mutant allele of ataxin-1 to cause disease it must be transported to the nucleus of the neuron. Using an in vitro RNA-binding assay, we demonstrate that ataxin-1 does bind RNA and that this binding diminishes as the length of its polyglutamine tract increases. These observations suggest that ataxin-1 plays a role in RNA metabolism and that the expansion of the polyglutamine tract may alter this function.

PMID: 11136710 [PubMed - indexed for MEDLINE]