Many mutations confer one or more toxic function(s) on copper/zinc superoxide dismutase 1 (SOD1) that impair motor neuron viability and cause familial amyotrophic lateral sclerosis (FALS). Using a conformation-specific antibody that detects misfolded SOD1 (C4F6), we found that oxidized wild-type SOD1 and mutant SOD1 share a conformational epitope that is not present in normal wild-type SOD1. In a subset of human sporadic ALS (SALS) cases, motor neurons in the lumbosacral spinal cord were markedly C4F6 immunoreactive, indicating that an aberrant wild-type SOD1 species was present. Recombinant, oxidized wild-type SOD1 and wild-type SOD1 immunopurified from SALS tissues inhibited kinesin-based fast axonal transport in a manner similar to that of FALS-linked mutant SOD1. Our findings suggest that wild-type SOD1 can be pathogenic in SALS and identify an SOD1-dependent pathogenic mechanism common to FALS and SALS.
Recommended CitationBosco, Daryl A; Morfini, Gerardo; Karabacak, N Murat; Song, Yuyu; Gros-Louis, Francois; Pasinelli, Piera; Goolsby, Holly; Fontaine, Benjamin A; Lemay, Nathan; McKenna-Yasek, Diane; Frosch, Matthew P; Agar, Jeffrey N; Julien, Jean-Pierre; Brady, Scott T; and Brown, Robert H, "Wild-type and mutant SOD1 share an aberrant conformation and a common pathogenic pathway in ALS." (2010). Farber Institute for Neurosciences Faculty Papers. Paper 18.