Figure 1. Selenoprotein involvement in cellular antioxidant systems.
Selenoproteins (highlighted in blue) have critical roles in both the GSH-dependent and TRX-dependent antioxidant systems. GPXs catalyse the breakdown of peroxides into water. SelH increases expression of the GSH-synthesis enzyme GCS (γ-glutamylcysteine synthetase). TRXRs reduce oxidized TRXs. Certain selenoproteins, such as SelR and SelP, use TRX as an electron donor to form redox couples for detoxification of oxidized proteins and lipids. Protein/Lipid could be protein phosphatases, protein kinases, transcription factors or membrane protein/lipids. GSR, glutathione reductase; SOD, superoxide dismutase. An animated version of this Figure can be seen at http://www.BiochemJ.org/bj/422/0011/bj4220011add.htm.