Recycling of peroxiredoxin IV provides a novel pathway for disulphide formation in the endoplasmic reticulum.

Disulphide formation in the endoplasmic reticulum (ER) is catalysed by members of the protein disulphide isomerase (PDI) family. These enzymes can be oxidized by the flavoprotein ER oxidoreductin 1 (Ero1), which couples disulphide formation with reduction of oxygen to form hydrogen peroxide (H(2)O(2)). The H(2)O(2) produced can be metabolized by ER-localized peroxiredoxin IV (PrxIV).