Regulation of H₂O₂ transport across cell membranes

The senior author of this chapter remembers vividly the intense discussions with Christine Winterbourn in two Gordon Research Conferences on Thiol signaling. In the first one, Christine commented with skepticism on our data indicating that-at concentrations lower than 100 μM-exogenous H₂O₂ needs AQP8 to gain access into HeLa cells. Considering her knowledge and experience, my team and I were quite worried. Much happier were we two years later, when Christine accepted the role of 366AQP8, maintaining however that membrane permeability to H₂O₂ was a controversial issue. We are now firmly convinced that peroxiporins regulate H₂O₂ transport and hence redox signaling, and hope that Christine’s remaining doubts will disappear upon reading this chapter, which is warmly dedicated to her.