Carmona, Mercède Cubas, LauraBautista, EricMoral-Blanch, MartaMedrano-Fernández, IriaSitia, RobertoBoronat i Llop, Susanna, 1965-Ayté del Olmo, JoséHidalgo Hernando, Elena2019-10-082019-10-082019Carmona M, de Cubas L, Bautista E, Moral-Blanch M, Medraño-Fernández I, Sitia R et al. Monitoring cytosolic H2O2 fluctuations arising from altered plasma membrane gradients or from mitochondrial activity. Nat Commun. 2019;10(1):4526. DOI: 10.1038/s41467-019-12475-02041-1723http://hdl.handle.net/10230/42405Genetically encoded probes monitoring H2O2 fluctuations in living organisms are key to decipher redox signaling events. Here we use a new probe, roGFP2-Tpx1.C169S, to monitor pre-toxic fluctuations of peroxides in fission yeast, where the concentrations linked to signaling or to toxicity have been established. This probe is able to detect nanomolar fluctuations of intracellular H2O2 caused by extracellular peroxides; expression of human aquaporin 8 channels H2O2 entry into fission yeast decreasing membrane gradients. The probe also detects H2O2 bursts from mitochondria after addition of electron transport chain inhibitors, the extent of probe oxidation being proportional to the mitochondrial activity. The oxidation of this probe is an indicator of steady-state levels of H2O2 in different genetic backgrounds. Metabolic reprogramming during growth in low-glucose media causes probe reduction due to the activation of antioxidant cascades. We demonstrate how peroxiredoxin-based probes can be used to monitor physiological H2O2 fluctuations.application/pdfeng© The Author(s) 2019. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.info:eu-repo/semantics/articlehttp://dx.doi.org/10.1038/s41467-019-12475-0Chemical toolsStress signallinginfo:eu-repo/semantics/openAccess