Induction of Cu/Zn Superoxide Dismutase (SOD1) Aggregation in Living Cells

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive degeneration and loss of motor neurons that appears to spread through the neuroaxis in a spatiotemporally restricted manner. In the familial form of ALS, the presence of any one of over 180 inherited mutations in the gene that encodes Cu/Zn superoxide dismutase (SOD1) leads to its eventual misfolding and aggregation. Once the pathological SOD1 seed is formed, it can continue growing into a larger aggregate through nucleation of other SOD1 substrate molecules. To date, there is no effective and rapid method to study the nucleation of SOD1 or to test therapeutics against this mechanism in living cells. In this chapter, we describe a series of protocols used to study induced aggregation of SOD1 in a simple but robust cell culture model. This assay can also be used to evaluate the potential therapeutic efficacy of small molecules targeting the induced aggregation mechanisms of SOD1.