Selenoprotein W: Lysates

The function of Selenoprotein W is not entirely known, but the presence of the bound glutathione moiety indicates that SEPW1 is thought to function in oxidation-reduction catalysis and may play a role in selenium deficiency disorders such as white muscle disease in sheep and Keshan disease in humans. Recently, overexpression of SEPW1 was shown to be glutathione dependent and was shown to markedly reduce the sensitivity of cell lines to H2O2 cytotoxicity. Selenoprotein W encodes a selenoprotein, which contains a selenocysteine (Sec) residue at its active site. The selenocysteine is encoded by the UGA codon that normally signals translation termination. The 3' UTR of selenoprotein genes have a common stem-loop structure, the sec insertion sequence (SECIS), that is necessary for the recognition of UGA as a Sec codon rather than as a stop signal. This protein shows highest expression in skeletal muscle and heart, and may be involved in oxidation-reduction reactions. A retroprocessed pseudogene, SEPW1P, has been identified and mapped to chromosome 1p35-34.