Sandbox 7726

The protein-protein interaction (PPI) between Ataxin-1 (ATXN1) have been implicated in spinocerebellar ataxia type 1 (SCA1), a neurodegenerative disease primarily caused by polyglutamine expansion in the ATXN1 protein ^[1].

Function

The binding of CIC to ATXN1 AXH domain leads to the formation and stabilization of ATXN1 oligomers, which are postulated to be the precursors of the disease.

Disease

This disease is primarily caused by the polyglutamine expansion in the ATXN1 protein. However, other factors are also required for the development of SCA1 neuropathology, including phosphorylation of Ser776 and nuclear localization. The synergy between these factors are not yet fully elucidated.

Relevance

This is a rare neurodegenerative disease, only hitting 1 out 2 out of 100,000 people, and there is no therapeutic agent for this illness yet.

Structural highlights

Mutation studies of the complex showed that highly conserved residues of CIC, display hydrophobic contacts with highly conserved residues of the AXH domain, . These residues were found to be required for the PPI interaction as any combination mutation of these residues lead to the disruption of the PPI formation.