Gastrointestinal glutathione peroxidase.
The gastrointestinal glutathione peroxidase (GI-GPx) is the fourth member of the GPx family. In rodents, it is exclusively expressed in the gastrointestinal tract, in humans also in liver. It has, therefore, been discussed to function as a primary barrier against the absorption of ingested hydroperoxides. A vital function of GI-GPx can be deduced from the unusual stability of its mRNA under selenium-limiting conditions, the presence of low amounts of GI-GPx protein in selenium deficiency where cGPx is absent, and the fast reappearance of the GI-GPx protein upon refeeding of cultured cells with selenium compared to the slower reappearance of cGPx protein. Furthermore, the Secis efficiency of GI-GPx is low when compared to cGPx and PHGPx. It is, however, almost independent of the selenium status of the cells tested. All these characteristics rank GI-GPx high in the hierarchy of selenoproteins and point to a role of GI-GPx which might be more crucial than that of cGPx, at least in the gastrointestinal system.
Wingler
K
K
German Institute of Human Nutrition, Potsdam-Rehbrücke, Institute of Nutritional Science, University of Potsdam.
Brigelius-Flohé
R
R
D000818:Animals; D002874:Chromosome Mapping; D002883:Chromosomes, Human, Pair 14; D004064:Digestive System / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005979:Glutathione Peroxidase / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D011544:Pseudogenes; D012333:RNA, Messenger / Q000235:genetics; D012643:Selenium / Q000378:metabolism / Q000494:pharmacology
D012333:RNA, Messenger; D005979:Glutathione Peroxidase; D012643:Selenium