Open AccessAdaptive tolerance to oxidative stress and the induction of antioxidant enzymatic activities in Candida albicans are independent of the Hog1 and Cap1‐mediated pathways
Author(s) -
GónzalezPárraga Pilar,
AlonsoMonge Rebeca,
Plá Jesús,
Argüelles Juan Carlos
Publication year - 2010
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1111/j.1567-1364.2010.00654.x
Subject(s) - oxidative stress , menadione , superoxide dismutase , biology , candida albicans , catalase , trehalose , antioxidant , biochemistry , reactive oxygen species , corpus albicans , glutathione reductase , oxidative phosphorylation , glutathione , enzyme , microbiology and biotechnology , glutathione peroxidase
In the pathogenic yeast Candida albicans , the MAP‐kinase Hog1 mediates an essential protective role against oxidative stress, a feature shared with the transcription factor Cap1. We analysed the adaptive oxidative response of strains with both elements altered. Pretreatment with gentle doses of oxidants or thermal upshifts (28→37 and 37→42 °C) improved survival in the face of high concentrations of oxidants (50 mM H 2 O 2 or 40 mM menadione), pointing to a functional cross‐protective mechanism in the mutants. The oxidative challenge promoted a marked intracellular synthesis of trehalose, although hog1 (but not cap1 ) cells always displayed high basal trehalose levels. Hydrogen peroxide (H 2 O 2 ) induced mRNA expression of the trehalose biosynthetic genes ( TPS1 and TPS2 ) in the tested strains. Furthermore, oxidative stress also triggered a differential activation of various antioxidant activities, whose intensity was greater after HOG1 and CAP1 deletion. The pattern of activity was dependent on the oxidant dosage applied: low concentrations of H 2 O 2 (0.5–5 mM) clearly induced catalase and glutathione reductase (GR), whereas drastic H 2 O 2 exposure (50 mM) increased Mn‐superoxide dismutase (SOD) isozyme‐mediated SOD activity. These results firmly support the existence in C. albicans of both Hog1‐ and Cap1‐independent mechanisms against oxidative stress.