GPX1GPX8

GPX1GPX8 refers to the family of eight human glutathione peroxidase genes, GPX1 through GPX8. Members of this family encode enzymes that reduce hydrogen peroxide and organic hydroperoxides to water or corresponding alcohols, using reducing equivalents supplied by glutathione or related systems. Through these reactions, they help protect cells from oxidative damage and influence redox signaling pathways.

The GPX family is divided by the presence of selenocysteine in the active site. GPX1–GPX4 are canonical selenoproteins that incorporate selenocysteine during translation, whereas GPX5–GPX8 are non-selenoproteins in humans and generally utilize cysteine at the active site. Subcellular localization and tissue distribution vary: GPX1 and GPX2 are predominantly cytosolic, GPX3 is secreted into extracellular fluids, GPX4 functions on lipid membranes, and GPX7 and GPX8 are localized to the endoplasmic reticulum and participate in redox homeostasis within that compartment.

Physiologically, GPX enzymes contribute to protecting cells from oxidative stress, supporting membrane integrity, and modulating signaling processes influenced by reactive oxygen species. Altered expression or activity of GPX family members has been associated with various diseases, including cancer, neurodegenerative disorders, and metabolic conditions. Evolutionarily, the GPX1GPX8 cluster reflects diversification of function among paralogs, enabling tissue-specific roles and distinct regulatory mechanisms. The term GPX1GPX8 is commonly used to describe the entire gene family rather than a single protein, highlighting the collective contribution of these enzymes to cellular redox balance.