title: Association of Cu,Zn-type superoxide dismutase with mitochondria and peroxisomes.
abstract: The subcellular localization of Cu,Zn-type superoxide dismutase (Cu,Zn-SOD) was investigated in rat tissues and cultured human fibroblasts. Subcellular fractionation, Nycodenz gradient centrifugation, and immunoblot analysis using specific antibodies showed that Cu,Zn-SOD was localized in cytosol, mitochondria, and peroxisomes of rat liver and brain. Treatment of highly purified mitochondria from rat liver with either Chaps or Triton X-100 released the bound Cu,Zn-SOD into supernatant fraction. Depolarization of mitochondria by inorganic phosphate and Ca(2+) released both Cu,Zn-SOD and cytochrome c from mitochondria. Digitonin also released Cu,Zn-SOD but not cytochrome c from mitochondria. Confocal immunofluorescence microscopy revealed that anti-Cu,Zn-SOD antibody in cultured human fibroblasts was found to colocalize with antibodies to Mn-SOD and PMP-70, markers of mitochondria and peroxisomes, respectively. Incubation of human Cu,Zn-SOD with purified mitochondria resulted in their association. These results indicate that Cu,Zn-SOD associates with mitochondria and peroxisomes in various cell types such as those in brain, liver, and skin.
authors.affiliation: Department of Biochemistry and Molecular Pathology, Osaka City University Medical School, 1-4-3 Asahimachi, Abeno, Osaka, 545-8585, Japan.
authors.forename: Yukimi
authors.initials: Y
authors.lastname: Kira
authors.forename: Eisuke F
authors.initials: EF
authors.lastname: Sato
authors.forename: Masayasu
authors.initials: M
authors.lastname: Inoue
mesh_terms: D000818:Animals; D001921:Brain / Q000201:enzymology; D002478:Cells, Cultured; D003600:Cytosol / Q000201:enzymology; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000201:enzymology*; D020675:Peroxisomes / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000166:cytology / Q000201:enzymology; D013482:Superoxide Dismutase / Q000032:analysis* / Q000276:immunology
chemical_list: D013482:Superoxide Dismutase