Transcripts of sunflower antioxidant scavengers of the SOD and GPX families accumulate differentially in response to downy mildew infection, phytohormones, reactive oxygen species, nitric oxide, protein kinase and phosphatase inhibitors

52 ref.absen

Immunolocalization of a plant glutathione peroxidase-like protein

absen

Two GPX-like proteins from Lycopersicon esculentum and Helianthus annuus are antioxidant enzymes with phospholipid hydroperoxide glutathione peroxidase and thioredoxin peroxidase activities

absen

Structural organization, chromosomal localization, expression and phylogenetic evaluation of mouse glutathione peroxidase encoding genes

National audienceWe have reported earlier the cloning and the chromosomal localization of 2 GPX-encoding sequences expressed differentially within the mouse epididymis, gpx5 and gpx3. Here, we have mapped on the mouse chromosomes the third known murine GPX-encoding gene, the cytosolic GPX or gpx1. We have compared the degree of identity of the 3 GPX proteins, the respective organization of the 3 corresponding single copy genes and, using degenerated oligonucleotides designed in highly conserved domains of the proteins, we have analyzed the expression of GPX-encoding genes in the mouse epididymis as well as in control tissues known to express GPX proteins (the liver for GPX1 and the kidney for GPX3). The 3 genes characterized to date were found expressed in each of the tissues tested but in a highly tissue-restricted manner. Nucleotidic sequences comparisons were carried out on GPX-encoding sequences from various species and were used to draw a dendrogram. Phylogenetic evaluation of the sequence information, as well as the chromosomal localizations, suggest that the GPX genes have evolved by duplication events followed by random insertions from a single ancestral gene

Characterization of an androgen response element within the promoter of the epididymis-specific murine glutathione peroxidase 5 gene

International audienceWe have shown in earlier studies, using a mouse model, that the expression of the glutathione peroxidase 5 protein (GPX5) is restricted to the epididymis and that the accumulation of its corresponding mRNA is hormonally, spatially and temporally regulated throughout postnatal development. We report here, using run-on assays, transient expression experiments as well as gel-shift and footprinting analyses on the findings that at least part of the androgenic control of the GPX5 expression is exerted at the transcriptional level via an androgen response element localized in the distal promoter region of the GPX5 gene. The gpx5 androgen response element (ARE) is found to be consistent with the consensus palindromic steroid-receptor target sequence 5'-AGWACWnnnTGTYCT-3' but exhibits a quite weak conservation in the left half site. The data presented here further expand the diversity of sequence able to confer androgen responsiveness

Identification of sperm antigens as a first step towards the generation of a contraceptive vaccine to decrease fossorial water vole Arvicola terrestris Scherman proliferations

International audienc

Structural organization, chromosomal localization, expression and phylogenetic evaluation of mouse glutathione peroxidase encoding genes

National audienceWe have reported earlier the cloning and the chromosomal localization of 2 GPX-encoding sequences expressed differentially within the mouse epididymis, gpx5 and gpx3. Here, we have mapped on the mouse chromosomes the third known murine GPX-encoding gene, the cytosolic GPX or gpx1. We have compared the degree of identity of the 3 GPX proteins, the respective organization of the 3 corresponding single copy genes and, using degenerated oligonucleotides designed in highly conserved domains of the proteins, we have analyzed the expression of GPX-encoding genes in the mouse epididymis as well as in control tissues known to express GPX proteins (the liver for GPX1 and the kidney for GPX3). The 3 genes characterized to date were found expressed in each of the tissues tested but in a highly tissue-restricted manner. Nucleotidic sequences comparisons were carried out on GPX-encoding sequences from various species and were used to draw a dendrogram. Phylogenetic evaluation of the sequence information, as well as the chromosomal localizations, suggest that the GPX genes have evolved by duplication events followed by random insertions from a single ancestral gene

Characterization of an androgen response element within the promoter of the epididymis-specific murine glutathione peroxidase 5 gene

International audienceWe have shown in earlier studies, using a mouse model, that the expression of the glutathione peroxidase 5 protein (GPX5) is restricted to the epididymis and that the accumulation of its corresponding mRNA is hormonally, spatially and temporally regulated throughout postnatal development. We report here, using run-on assays, transient expression experiments as well as gel-shift and footprinting analyses on the findings that at least part of the androgenic control of the GPX5 expression is exerted at the transcriptional level via an androgen response element localized in the distal promoter region of the GPX5 gene. The gpx5 androgen response element (ARE) is found to be consistent with the consensus palindromic steroid-receptor target sequence 5'-AGWACWnnnTGTYCT-3' but exhibits a quite weak conservation in the left half site. The data presented here further expand the diversity of sequence able to confer androgen responsiveness

Impact du stress oxidant sur la qualité nucléaire spermatique

International audienc

Glutathione peroxidases (GPX) at work on epididymal spermatozoa: An example of the dual effect of reactive oxygen species on mammalian male fertilizing ability.

The mammalian glutathione peroxidase gene family encodes bi-functional enzymes that can work either as classical reactive oxygen species (ROS) scavengers or as thiol-peroxidases, thereby introducing disulfide bridges in thiol-containing proteins. These dual effects are nowhere better demonstrated than in epididymal maturing spermatozoa where the concomitant actions of several glutathione peroxidases ensure the achievement of the structural maturation of sperm cells as well as their protection against ROS-induced damage. We review here the roles played by the sperm-associated forms of GPx4 (mitochondrial GPx4 and nuclear GPx4), the secreted GPx5 protein as well as the epithelial proteins GPx1, GPx3 and cellular GPx4, all functioning in the mammalian epididymis at different stages of the sperm's epididymal journey, and in different epididymis compartments