InterPro domain: IPR011893

This entry represents the Rdx family of selenoproteins, which includes mammalian selenoproteins SelW, SelV, SelT and SelH, bacterial SelW-like proteins and cysteine-containing proteins of unknown function in all three domains of life. Mammalian Rdx12 and its fish selenoprotein orthologues are also members of this family [ 1 ]. These proteins possess a thioredoxin-like fold and a conserved CXXC or CxxU (U is selenocysteine) motif near the N terminus, suggesting a redox function. Rdx proteins can use catalytic cysteine (or selenocysteine) to form transient mixed disulphides with substrate proteins. Selenium (Se) plays an essential role in cell survival and most of the effects of Se are probably mediated by selenoproteins.

Selenoprotein W (SelW) plays an important role in protection of neurons from oxidative stress during neuronal development [ 2 ], [ 3 ].

Selenoprotein T (SelT) is conserved from plants to humans. SelT is localized to the endoplasmic reticulum through a hydrophobic domain. The protein binds to UDP-glucose:glycoprotein glucosyltransferase (UGTR), the endoplasmic reticulum (ER)-resident protein, which is known to be involved in the quality control of protein folding [ 4 , 5 ]. The function of SelT is unknown, although it may have a role in PACAP signaling during PC12 cell differentiation [ 6 , 7 ].

Selenoprotein H (SelH) protects neurons against UVB-induced damage by inhibiting apoptotic cell death pathways, by preventing mitochondrial depolarization, and by promoting cell survival pathways [ 8 ].

1. SelT, SelW, SelH, and Rdx12: genomics and molecular insights into the functions of selenoproteins of a novel thioredoxin-like family. Biochemistry 46, 6871-82
2. Antioxidative role of selenoprotein W in oxidant-induced mouse embryonic neuronal cell death. Mol. Cells 27, 609-13
3. Selenoprotein W gene regulation by selenium in L8 cells. Biometals 15, 411-20
4. Association between the 15-kDa selenoprotein and UDP-glucose:glycoprotein glucosyltransferase in the endoplasmic reticulum of mammalian cells. J. Biol. Chem. 276, 15330-6
5. Structure-function relationships, physiological roles and evolution of mammalian ER-resident selenoproteins. Antioxid. Redox Signal. 22, 1756-68
6. Identification of novel genes expressed in hypoxic brain condition by fluorescence differential display. Forensic Sci. Int. 169, 168-72
7. Selenoprotein T is a PACAP-regulated gene involved in intracellular Ca2+ mobilization and neuroendocrine secretion. FASEB J. 220, 328-34
8. Overexpression of human selenoprotein H in neuronal cells ameliorates ultraviolet irradiation-induced damage by modulating cell signaling pathways. Exp. Neurol.