Title:
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Mitochondrial Hsp60, resistance to oxidative stress, and the labile iron pool are closely connected in Saccharomyces cerevisiae
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Author:
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Cabiscol Català, Elisa; Bellí i Martínez, Gemma; Tamarit Sumalla, Jordi; Echave Lozano, Pedro; Herrero Perpiñán, Enrique; Ros Salvador, Joaquim
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Notes:
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In the present study, we have analyzed the role of the
molecular chaperone Hsp60 in protection of Saccharo-
myces cerevisiae against oxidative damage. We con-
structed mutant strains in which the levels of Hsp60
protein, compared with wild-type cells, were four times
greater, and the addition of doxycycline gradually re-
duces them to 20% of wild-type. Under oxidative-stress
conditions, the progressive decrease in Hsp60 levels in
these mutants resulted in reduced cell viability and an
increase in both cell peroxide species and protein car-
bonyl content. Protection of Fe/S-containing enzymes
from oxidative inactivation was found to be dose-de-
pendent with respect to Hsp60 levels. As these enzymes
release their iron ions under oxidative-stress condi-
tions, the intracellular labile iron pool, monitored with
calcein, was higher in cells with reduced Hsp60 levels.
Consistently, the iron chelator deferoxamine protected
low Hsp60-expressing cells from both oxidant-induced
death and protein oxidation. These results indicate that
the role of Hsp60 in oxidative-stress defense is explained
by protection of several Fe/S proteins, which prevent
the release of iron ions and thereby avert further
damage. |
Rights:
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(c) The American Society for Biochemistry and Molecular Biology, 2002
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Document type:
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article publishedVersion |
Published by:
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The American Society for Biochemistry and Molecular Biology
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