Inhibition of chaperone activity is a shared property of several Cu,Zn-superoxide dismutase mutants that cause amyotrophic lateral sclerosis
Department of Biochemistry and Molecular Pharmacology; Department of Neurology; Department of Molecular Genetics and Microbiology
Amyotrophic Lateral Sclerosis; Animals; Humans; Mice; Mice, Inbred C57BL; Mice, Transgenic; Molecular Chaperones; *Mutation; Spinal Cord; Superoxide Dismutase
Life Sciences | Medicine and Health Sciences
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive motor neuron degeneration, paralysis, and death. Mutant Cu,Zn-superoxide dismutase (SOD1) causes a subset of ALS by an unidentified toxic property. Increasing evidence suggests that chaperone dysfunction plays a role in motor neuron degeneration in ALS. To investigate the relationship between mutant SOD1 expression and chaperone dysfunction, we measured chaperone function in central nervous system tissue lysates from normal mice and transgenic mice expressing human SOD1 variants. We observed a significant decrease in chaperone activity in tissues from mice expressing ALS-linked mutant SOD1 but not control mice expressing human wild type SOD1. This decrease was detected only in the spinal cord, became apparent by 60 days of age (before the onset of muscle weakness and significant motor neuron loss), and persisted throughout the late stages. In addition, this impairment of chaperone activity occurred only in cytosolic but not in mitochondrial and nuclear fractions. Furthermore, multiple recombinant human SOD1 mutants with differing biochemical and biophysical properties inhibited chaperone function in a cell-free extract of normal mouse spinal cords. Thus, mutant SOD1 proteins may impair chaperone function independent of gene expression in vivo, and this inhibition may be a shared property of ALS-linked mutant SOD1 proteins.
DOI of Published Version
J Biol Chem. 2005 May 6;280(18):17725-31. Epub 2005 Mar 7. Link to article on publisher's site
The Journal of biological chemistry
Tummala, Hemachand; Jung, Chelowha; Tiwari, Ashutosh; Higgins, Cynthia M. J.; Hayward, Lawrence J.; and Xu, Zuoshang, "Inhibition of chaperone activity is a shared property of several Cu,Zn-superoxide dismutase mutants that cause amyotrophic lateral sclerosis" (2005). Open Access Articles. 693.