Open AccessReactive oxygen species production induced by ethanol in S accharomyces cerevisiae increases because of a dysfunctional mitochondrial iron–sulfur cluster assembly system
Author(s) -
PérezGallardo Rocio V.,
Briones Luis S.,
DíazPérez Alma L.,
Gutiérrez Sergio,
RodríguezZavala José S.,
CamposGarcía Jesús
Publication year - 2013
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 - 10.1111/1567-1364.12090
Subject(s) - reactive oxygen species , biochemistry , saccharomyces cerevisiae , catalase , biology , mitochondrial ros , mitochondrion , antioxidant , superoxide dismutase , glutathione , microbiology and biotechnology , yeast , enzyme
Ethanol accumulation during fermentation contributes to the toxic effects in S accharomyces cerevisiae , impairing its viability and fermentative capabilities. The iron–sulfur ( F e– S ) cluster biogenesis is encoded by the ISC genes. Reactive oxygen species ( ROS ) generation is associated with iron release from F e– S ‐containing enzymes. We evaluated ethanol toxicity, ROS generation, antioxidant response and mitochondrial integrity in S . cerevisiae ISC mutants. These mutants showed an impaired tolerance to ethanol. ROS generation increased substantially when ethanol accumulated at toxic concentrations under the fermentation process. At the cellular and mitochondrial levels, ROS were increased in yeast treated with ethanol and increased to a higher level in the ssq1 ∆, isa1 ∆, iba57 ∆ and grx5 ∆ mutants – hydrogen peroxide and superoxide were the main molecules detected. Additionally, ethanol treatment decreased GSH / GSSG ratio and increased catalase activity in the ISC mutants. Examination of cytochrome c integrity indicated that mitochondrial apoptosis was triggered following ethanol treatment. The findings indicate that the mechanism of ethanol toxicity occurs via ROS generation dependent on ISC assembly system functionality. In addition, mutations in the ISC genes in S . cerevisiae contribute to the increase in ROS concentration at the mitochondrial and cellular level, leading to depletion of the antioxidant responses and finally to mitochondrial apoptosis.