Effects of Hydrogen Peroxide on 15-kDa Selenoprotein Transcription and Translation

摘要

@@Selenoproteins are proteins containing selenocysteine,in which the sulfur was replaced with selenium (Se).Seleno-cysteine is the 21~(st) amino acid coded by the common stop codon 'UGA' Translation of selenoprotein is combined with (SEC1S) located at 3'UTR and some translation factors specific for selenoproteins. 15-kDa selenoprotein (Sepl5) is a protein containing seleno-cysteine,whose molecular weight of mature protein is about 15 kDa (Gladyshev et al.,1998).It is reported that Sepl5 (Hatfield et al.,2006) and Se are respectively related to cancer prevention (Kumaraswamy,2000),while selenoprotiens are involved with antioxidant activity (Huang and Xu,2008).Stable cells transected with Sep 15 can increase cell vitality compare to control after treatment with hydrogen peroxide (H_2O_2) (Wu et al.,2003). to elucidate whether Sep 15 expression relates to the oxygen stress resistance of the cells,a human normal hepatocyte cell line-HLO2 was treated with H_2O_ 2. The mRNA levels of Sep 15 were quantified by real time PCR and the protein level of Sep 15 was detected by western blot.In order to select suitable concentrations of H_2O_2 for treatment,cell vitality was detected 72 hrs after treatment.