GPX2

The protein encoded by this gene belongs to the glutathione peroxidase family, members of which catalyze the reduction of organic hydroperoxides and hydrogen peroxide (H2O2) by glutathione, and thereby protect cells against oxidative damage. Several isozymes of this gene family exist in vertebrates, which vary in cellular location and substrate specificity. This isozyme is predominantly expressed in the gastrointestinal tract (also in liver in human), is localized in the cytoplasm, and whose preferred substrate is hydrogen peroxide. Overexpression of this gene is associated with increased differentiation and proliferation in colorectal cancer. This isozyme is also a selenoprotein, containing the rare amino acid selenocysteine (Sec) at its active site. 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. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Jul 2016]

该基因编码的蛋白质属于谷胱甘肽过氧化物酶家族，该家族成员通过谷胱甘肽催化有机过氧化氢和过氧化氢（H2O2）的还原，从而保护细胞免受氧化损伤。该基因家族在脊椎动物中存在多种同工酶，它们在细胞定位和底物特异性上存在差异。本同工酶主要在胃肠道（人类中亦存在于肝脏）表达，定位于细胞质中，其首选底物为过氧化氢。该基因的过表达与结直肠癌中的细胞分化和增殖增加有关。该同工酶亦为硒蛋白，在其活性位点含有稀有氨基酸硒半胱氨酸（Sec）。Sec由UGA密码子编码，通常作为翻译终止信号。硒蛋白mRNA的3'非翻译区（3' UTRs）含有保守的发夹结构，称为Sec插入序列（SECIS）元件，该元件对于将UGA识别为Sec密码子而非终止信号至关重要。此外，针对该基因还发现了可变剪接的转录变体。[由RefSeq提供，2016年7月]