Multi-omic profiling reveals the ataxia protein sacsin is required for integrin trafficking and synaptic organization.

Abstract

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a childhood-onset cerebellar ataxia caused by mutations in SACS, which encodes the protein sacsin. Cellular ARSACS phenotypes include mitochondrial dysfunction, intermediate filament disorganization, and progressive death of cerebellar Purkinje neurons. It is unclear why the loss of sacsin causes these deficits or why they manifest as cerebellar ataxia. Here, we perform multi-omic profiling in sacsin knockout (KO) cells and identify alterations in microtubule dynamics and mislocalization of focal adhesion (FA) proteins, including multiple integrins. Deficits in FA structure, signaling, and function can be rescued by targeting PTEN, a negative regulator of FA signaling. ARSACS mice possess mislocalization of ITGA1 in Purkinje neurons and synaptic disorganization in the deep cerebellar nucleus (DCN). The sacsin interactome reveals that sacsin regulates interactions between cytoskeletal and synaptic adhesion proteins. Our findings suggest that disrupted trafficking of synaptic adhesion proteins is a causal molecular deficit in ARSACS.

• Authors: Lisa E L Romano, Wen Yih Aw, Kathryn M Hixson, Tatiana V Novoselova, Tammy M Havener, Stefanie Howell, Bonnie Taylor-Blake, Charlotte L Hall, Lei Xing, Josh Beri, Suran Nethisinghe, Laura Perna, Abubakar Hatimy, Ginevra Chioccioli Altadonna, Lee M Graves, Laura E Herring, Anthony J Hickey, Konstantinos Thalassinos, J Paul Chapple, Justin M Wolter
• Journal: Cell reports (Cell Rep) Vol. 41 Issue 5 Pg. 111580 (11 01 2022) ISSN: 2211-1247 [Electronic] United States
• PMID: 36323248 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural)
• Copyright: Crown Copyright © 2022. Published by Elsevier Inc. All rights reserved.

Chemical References

• Integrins
• Heat-Shock Proteins

Topics

• Mice
• Animals
• Cerebellar Ataxia
• Integrins (genetics)
• Heat-Shock Proteins (metabolism)
• Ataxia (genetics)
• Mutation