Activation of redox cascades through hydrogen peroxide-mediated reversible cysteine oxidation is a major mechanism for intracellular signaling. Understanding why some cysteine residues are specifically oxidized, in competition with other proximal cysteine residues and in the presence of strong redox buffers, is therefore crucial for understanding redox signaling. In this review, we explore the recent advances in thiol-redox chemistry linked to signaling. We describe the last findings in the field of redox sensors, those that are naturally present in different model organisms as well as those that have been engineered to quantify intracellular hydrogen peroxide concentrations. Finally, we provide a summary of the newest approaches developed to study reversible cysteine oxidation at the proteomic level.This work was supported by the Spanish Ministry of Science and Innovation (BFU2012-32045), PLAN E and FEDER, by the Spanish program Consolider-Ingenio 2010 Grant CSD 2007-0020, and by Grant SGR2009-195 from Generalitat de Catalunya (Spain) to E.H. E.H. is the recipient of an ICREA Academia Award (Generalitat de Catalunya)
