The complete sequence of the mouse epididymal protein (MEP24) was cloned. It contains a 663 bp open-reading frame that, after conceptual translation, shows extensive identity with proteins belonging to the glutathione peroxidase (GPX) family. However, a major difference between GPX5 (MEP24) and other known GPXs concerns a protein domain known to be critical for GPX function. To find out what could be the physiological function of such a protein in the mouse epididymis, we have used a mammalian expression system to overexpress the GPX5 protein. Cells constitutively expressing the GPX5 protein were generated and assayed for their ability to metabolize regular substrates of GPX enzymes. Data presented here show that the GPX5-expressing cells can metabolize hydrogen peroxide in a manner that is consistent with a peroxidase activity. However, the substrate preference of the GPX5-expressing cells and their apparent insensitivity to a regular inhibitor of GPX enzymes suggest that the GPX5 protein belongs to a particular class of GPX proteins. Involvement of this protein in the physiology of the mouse epididymis is discussed.
Using a reverse transcription PCR (RT‐PCR) amplification strategy, with degenerate primers localized in highly conserved domains of known glutathione peroxidase (GPX) proteins, GPX‐encoding cDNA fragments were generated from sunflower (Helianthus annuus L.) hypocotyl RNA. Along with the sequences of two distinct GPX‐encoding cDNAs (GPXha‐1 and GPXha‐2) and the alignment of their conceptually translated products with to date cloned plant GPXs, we report here that the two corresponding mRNAs are qualitatively and quantitatively differentially expressed in various organs of H. annuus. Using northern blotting we have shown that more sunflower GPX‐like transcripts accumulate in plants which have been subjected to either wounding or infection by a biotrophic pathogen (Plasmopara halstedii) suggesting that the corresponding genes are inducible under various stress conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.