Perspective on SOD1 mediated toxicity in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive degeneration of spinal motor neurons. Although mutations in dozens of proteins have been associated with ALS, the enzyme, superoxide dismutase 1 (SOD1) was the first protein identified with the development of ALS and accounts for ~20% of familial cases. In experimental animals and patient samples, mutant SOD1 is found in cytoplasmic deposits implicating SOD1 aggregates as the toxic entities. Here we discuss the various biochemical and structure-based hypotheses proposed for mutant SOD1-associated ALS. Although much remains to be discovered about the molecular mechanism of SOD1 mediated toxicity, these hypotheses offer new avenues for therapeutic development.