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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Thiol Peroxidases as Major Regulators of Intracellular Levels of Peroxynitrite in Live Saccharomyces cerevisiae Cells

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Author(s):
Condeles, Andre Luis [1] ; Gomes, Fernando [2] ; de Oliveira, Marcos Antonio [3] ; Soares Netto, Luis Eduardo [2] ; Toledo Junior, Jose Carlos [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Dept Quim, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto - Brazil
[2] Univ Sao Paulo, Inst Biociencias, Dept Genet & Biol Evolut, BR-05508090 Sao Paulo, SP - Brazil
[3] Univ Estadual Paulista, Inst Biociencias, Campus Litoral Paulista, BR-11330900 Sao Paulo, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: ANTIOXIDANTS; v. 9, n. 5 MAY 2020.
Web of Science Citations: 0
Abstract

Thiol peroxidases (TP) are ubiquitous and abundant antioxidant proteins of the peroxiredoxin and glutathione peroxidase families that can catalytically and rapidly reduce biologically relevant peroxides, such as hydrogen peroxide and peroxynitrite. However, the TP catalytic cycle is complex, depending on multiple redox reactions and partners, and is subjected to branching and competition points that may limit their peroxide reductase activity in vivo. The goals of the present study were to demonstrate peroxynitrite reductase activity of TP members in live cells in real time and to evaluate its catalytic characteristics. To these ends, we developed a simple fluorescence assay using coumarin boronic acid (CBA), exploiting that fact that TP and CBA compete for peroxynitrite, with the expectation that higher TP peroxynitrite reductase activity will lower the CBA oxidation. TP peroxynitrite reductase activity was evaluated by comparing CBA oxidation in live wild type and genetically modified Delta 8 (TP-deficient strain) and Delta 8+TSA1 (Delta 8 strain that expresses only one TP member, the TSA1 gene) Saccharomyces cerevisiae strains. The results showed that CBA oxidation decreased with cell density and increased with increasing peroxynitrite availability. Additionally, the rate of CBA oxidation decreased in the order Delta 8 > Delta 8+TSA1 > WT strains both in control and glycerol-adapted (expressing higher TP levels) cells, showing that the CBA competition assay could reliably detect peroxynitrite in real time in live cells, comparing CBA oxidation in strains with reduced and increased TP expression. Finally, there were no signs of compromised TP peroxynitrite reductase activity during experimental runs, even at the highest peroxynitrite levels tested. Altogether, the results show that TP is a major component in the defense of yeast against peroxynitrite insults under basal and increasing stressful conditions. (AU)

FAPESP's process: 13/07937-8 - Redoxome - Redox Processes in Biomedicine
Grantee:Ohara Augusto
Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
FAPESP's process: 17/09443-3 - Importing of peroxiredoxins to distinct mitochondrial compartments: impacts on physiology and pathology
Grantee:Fernando Gomes
Support Opportunities: Scholarships in Brazil - Post-Doctoral