Regulation of redox signaling mediated by H2O2 transporters

The main sources of H2O2 production are physically separated from its targets in and between cells. This condition sustains the formation of gradients that permit the transmission of redox signals by this second messenger. Passive diffusion was long assumed to allow H2O2 transport across lipid bilayers. However, in the last decade it has become clear that H2O2 is routed by a subgroup of aquaporin (AQP) channels, (peroxiporins) whose permeability can be modulated to adapt fluxes and hence signal strength and duration. Thus, the plasma membrane peroxiporin AQP8 is regulated by redox-mediated mechanisms impacting a conserved cysteine, and its open or closed state fuels or inhibits H2O2 downstream pathways, respectively. More recently, we found that AQP11 acts as a resident peroxiporin in the membrane of the endoplasmic reticulum (ER), maintaining organelle redoxtasis. Altogether, our results suggest that different peroxiporins are used to activate different targets depending on their subcellular distribution, interactors and permeability. Therefore, peroxiporins provide to redox signaling an extra layer of spatio-temporal specificity, assuring timed release of redox signal transducers in topologically restrained intra- or inter-cellular locations. Supported by AIRC, Spanish Ministry of Science and Innovation-UC3M and Marie Skłodowska-Curie program-Polish Ministry of Science and Higher Education

Regulation of redox signaling mediated by H2O2 transporters Articles