The protein encoded by this gene belongs to the selenoprotein M/SEP15 family. The exact function of this protein is not known, but it may have a role in maintaining redox homeostasis. It is localized in the perinuclear region, and is highly expressed in the brain in mammals. This protein is a selenoprotein, containing the rare amino acid selenocysteine (Sec). Sec is encoded by the UGA codon, which normally signals translation termination. The 3' UTRs of selenoprotein mRNAs contain a conserved stem-loop structure, designated the Sec insertion sequence (SECIS) element, that is necessary for the recognition of UGA as a Sec codon, rather than as a stop signal. A homeolog of this gene is found on chromosome 1S.[provided by RefSeq, Dec 2016].