Mitochondrial localization of mutant superoxide dismutase 1 triggers caspase-dependent cell death in a cellular model of familial amyotrophic lateral sclerosis.
The mutations in superoxide dismutase 1 (SOD1) cause approximately 20% of familial amyotrophic lateral sclerosis cases. A toxic gain of function has been considered to be the cause of the disease, but its molecular mechanism remains uncertain. To determine whether the subcellular localization of mutant SOD1 is crucial to mutant SOD1-mediated cell death, we produced neuronal cell models with accumulation of SOD1 in each subcellular fraction/organelle, such as the cytosol, nucleus, endoplasmic reticulum, and mitochondria. We showed that the localization of mutant SOD1 in the mitochondria triggered the release of mitochondrial cytochrome c followed by the activation of caspase cascade and induced neuronal cell death without cytoplasmic mutant SOD1 aggregate formation. Nuclear and endoplasmic reticulum localization of mutant SOD1 did not induce cell death. These results suggest that the localization of mutant SOD1 in the mitochondria is critical in the pathogenesis of mutant SOD1-associated familial amyotrophic lateral sclerosis.
Takeuchi
Hideyuki
H
Department of Neurology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
Kobayashi
Yasushi
Y
Ishigaki
Shinsuke
S
Doyu
Manabu
M
Sobue
Gen
G
D019943:Amino Acid Substitution; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D016923:Cell Death / Q000502:physiology*; D003574:Cytochrome c Group / Q000032:analysis; D004791:Enzyme Inhibitors / Q000494:pharmacology; D049452:Green Fluorescent Proteins; D006801:Humans; D020287:In Situ Nick-End Labeling; D007700:Kinetics; D008164:Luminescent Proteins / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology*; D008954:Models, Biological; D016472:Motor Neuron Disease / Q000201:enzymology / Q000235:genetics*; D009447:Neuroblastoma; D009474:Neurons / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics* / Q000378:metabolism; D000072105:Superoxide Dismutase-1; D013997:Time Factors; D014162:Transfection; D014407:Tumor Cells, Cultured
D061945:Caspase Inhibitors; D003574:Cytochrome c Group; D004791:Enzyme Inhibitors; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; C000606290:SOD1 protein, human; D049452:Green Fluorescent Proteins; C109415:SOD1 G93A protein; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D020169:Caspases