Cu,Zn-superoxide dismutase plays an important role in protecting cells from oxygen toxicity by catalyzing the dismutation of superoxide anion into hydrogen peroxide and oxygen. In Saccharomyces cerevisiae Cu,Zn-superoxide dismutase is coregulated with copper-thionein by copper via the transcription factor ACE 1. We demonstrate here that presence of AgNO3 in the culture medium leads to a five times increase of Cu,Zn-superoxide dismutase mRNA, with a concomitant six times decrease of the enzyme activity. Susceptibility of yeast to silver was apparently inversely related to Cu,Zn-superoxide dismutase activity. From silver-treated yeast a Cu,Zn-superoxide dismutase with impaired dismutase function was purified and was shown to contain silver, which was located to the copper site. These data suggest that Cu,Zn-superoxide dismutase may play an additional direct role in the defense of S. cerevisiae against metal stress by functioning as metal chelator.
Ciriolo, M.r., Civitareale, P., Carri', M.t., DE MARTINO, A., Galiazzo, F., Rotilio, G. (1994). Purification and characterization of Ag,Zn-superoxide dismutase from Saccharomyces cerevisiae exposed to silver. THE JOURNAL OF BIOLOGICAL CHEMISTRY, 269(41), 25783-25787.
Purification and characterization of Ag,Zn-superoxide dismutase from Saccharomyces cerevisiae exposed to silver
CIRIOLO, MARIA ROSA;CIVITAREALE, PATRIZIA;CARRI', MARIA TERESA;DE MARTINO, ANGELO;ROTILIO, GIUSEPPE
1994-10-14
Abstract
Cu,Zn-superoxide dismutase plays an important role in protecting cells from oxygen toxicity by catalyzing the dismutation of superoxide anion into hydrogen peroxide and oxygen. In Saccharomyces cerevisiae Cu,Zn-superoxide dismutase is coregulated with copper-thionein by copper via the transcription factor ACE 1. We demonstrate here that presence of AgNO3 in the culture medium leads to a five times increase of Cu,Zn-superoxide dismutase mRNA, with a concomitant six times decrease of the enzyme activity. Susceptibility of yeast to silver was apparently inversely related to Cu,Zn-superoxide dismutase activity. From silver-treated yeast a Cu,Zn-superoxide dismutase with impaired dismutase function was purified and was shown to contain silver, which was located to the copper site. These data suggest that Cu,Zn-superoxide dismutase may play an additional direct role in the defense of S. cerevisiae against metal stress by functioning as metal chelator.Questo articolo è pubblicato sotto una Licenza Licenza Creative Commons