Glutathione peroxidase 5 (GPx-5), also known as epididymal secretory glutathione peroxidase is an enzyme that in humans is encoded by the GPX5gene.[5][6]
GPx-5 belongs to the glutathione peroxidase family. It is specifically expressed in the epididymis in the mammalian male reproductive tract, and is androgen-regulated. Unlike mRNAs for other characterized glutathione peroxidases, this mRNA does not contain a selenocysteine (UGA) codon. Thus, the encoded protein is selenium-independent, and has been proposed to play a role in protecting the membranes of spermatozoa from the damaging effects of lipid peroxidation and/or preventing premature acrosome reaction. Alternatively spliced transcript variants encoding different isoforms have been described for this gene.[5]
Richard MJ, Guiraud P, Didier C, et al. (2001). "Human immunodeficiency virus type 1 Tat protein impairs selenoglutathione peroxidase expression and activity by a mechanism independent of cellular selenium uptake: consequences on cellular resistance to UV-A radiation". Arch. Biochem. Biophys. 386 (2): 213–20. doi:10.1006/abbi.2000.2197. PMID11368344.
Opalenik SR, Ding Q, Mallery SR, Thompson JA (1998). "Glutathione depletion associated with the HIV-1 TAT protein mediates the extracellular appearance of acidic fibroblast growth factor". Arch. Biochem. Biophys. 351 (1): 17–26. doi:10.1006/abbi.1997.0566. PMID9501919.
Rejraji H, Vernet P, Drevet JR (2002). "GPX5 is present in the mouse caput and cauda epididymidis lumen at three different locations". Mol. Reprod. Dev. 63 (1): 96–103. doi:10.1002/mrd.10136. PMID12211066. S2CID8103049.
Vernet P, Faure J, Dufaure JP, Drevet JR (1997). "Tissue and developmental distribution, dependence upon testicular factors and attachment to spermatozoa of GPX5, a murine epididymis-specific glutathione peroxidase". Mol. Reprod. Dev. 47 (1): 87–98. doi:10.1002/(SICI)1098-2795(199705)47:1<87::AID-MRD12>3.0.CO;2-X. PMID9110319.
Price TO, Ercal N, Nakaoke R, Banks WA (2005). "HIV-1 viral proteins gp120 and Tat induce oxidative stress in brain endothelial cells". Brain Res. 1045 (1–2): 57–63. doi:10.1016/j.brainres.2005.03.031. PMID15910762. S2CID7362454.