title: Malfunctioning of the iron-sulfur cluster assembly machinery in Saccharomyces cerevisiae produces oxidative stress via an iron-dependent mechanism, causing dysfunction in respiratory complexes.
abstract: Biogenesis and recycling of iron-sulfur (Fe-S) clusters play important roles in the iron homeostasis mechanisms involved in mitochondrial function. In Saccharomyces cerevisiae, the Fe-S clusters are assembled into apoproteins by the iron-sulfur cluster machinery (ISC). The aim of the present study was to determine the effects of ISC gene deletion and consequent iron release under oxidative stress conditions on mitochondrial functionality in S. cerevisiae. Reactive oxygen species (ROS) generation, caused by H2O2, menadione, or ethanol, was associated with a loss of iron homeostasis and exacerbated by ISC system dysfunction. ISC mutants showed increased free Fe2+ content, exacerbated by ROS-inducers, causing an increase in ROS, which was decreased by the addition of an iron chelator. Our study suggests that the increment in free Fe2+ associated with ROS generation may have originated from mitochondria, probably Fe-S cluster proteins, under both normal and oxidative stress conditions, suggesting that Fe-S cluster anabolism is affected. Raman spectroscopy analysis and immunoblotting indicated that in mitochondria from SSQ1 and ISA1 mutants, the content of [Fe-S] centers was decreased, as was formation of Rieske protein-dependent supercomplex III2IV2, but this was not observed in the iron-deficient ATX1 and MRS4 mutants. In addition, the activity of complexes II and IV from the electron transport chain (ETC) was impaired or totally abolished in SSQ1 and ISA1 mutants. These results confirm that the ISC system plays important roles in iron homeostasis, ROS stress, and in assembly of supercomplexes III2IV2 and III2IV1, thus affecting the functionality of the respiratory chain.
authors.affiliation: Lab. Biotecnología Microbiana, Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Gomez
authors.affiliation: Lab. Biotecnología Microbiana, Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
authors.forename: Rocío V
authors.initials: RV
authors.lastname: Pérez-Gallardo
authors.affiliation: Lab. Biotecnología Microbiana, Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Sánchez
authors.affiliation: Lab. Biotecnología Microbiana, Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
authors.forename: Alma L
authors.initials: AL
authors.lastname: Díaz-Pérez
authors.affiliation: Lab. de Bioquímica, Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
authors.forename: Christian
authors.initials: C
authors.lastname: Cortés-Rojo
authors.affiliation: Lab. Biotecnología Microbiana, Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
authors.forename: Victor
authors.initials: V
authors.lastname: Meza Carmen
authors.affiliation: Lab. de Bioquímica, Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Saavedra-Molina
authors.affiliation: Facultad de Ingeniería Química, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
authors.forename: Javier
authors.initials: J
authors.lastname: Lara-Romero
authors.affiliation: Centro de Investigación y de Estudios Avanzados del IPN, Unidad Querétaro, Querétaro, México.
authors.forename: Sergio
authors.initials: S
authors.lastname: Jiménez-Sandoval
authors.affiliation: Centro de Investigación y de Estudios Avanzados del IPN, Unidad Querétaro, Querétaro, México.
authors.forename: Francisco
authors.initials: F
authors.lastname: Rodríguez
authors.affiliation: Departamento de Bioquímica, Instituto Nacional de Cardiología, México, D.F., México.
authors.forename: José S
authors.initials: JS
authors.lastname: Rodríguez-Zavala
authors.affiliation: Lab. Biotecnología Microbiana, Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
authors.forename: Jesús
authors.initials: J
authors.lastname: Campos-García
mesh_terms: D000332:Aerobiosis / Q000187:drug effects; D045222:Electron Transport Chain Complex Proteins / Q000378:metabolism*; D007501:Iron / Q000494:pharmacology*; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D016877:Oxidants / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*
chemical_list: D045222:Electron Transport Chain Complex Proteins; D007506:Iron-Sulfur Proteins; D016877:Oxidants; D017382:Reactive Oxygen Species; D007501:Iron