GPX2

GPX2, or glutathione peroxidase 2, is a member of the glutathione peroxidase family of selenium-dependent enzymes. Like other family members, it catalyzes the reduction of hydrogen peroxide and organic hydroperoxides to water and corresponding alcohols, using glutathione as the electron donor. This places GPX2 in the cellular antioxidant defense system that helps limit oxidative damage.

GPX2 is expressed primarily in the gastrointestinal tract, particularly the colon, but detectable levels can be found in other tissues as well. The enzyme is generally localized in the cytosol, and its activity relies on a selenocysteine residue at the active site, which is encoded by a UGA codon and requires a SECIS element for proper incorporation during translation.

Regulation of GPX2 expression responds to oxidative and inflammatory signals. NRF2-activated pathways and other redox-sensitive transcriptional networks are implicated in its upregulation under stress, reflecting a role in protecting mucosal and epithelial cells from oxidative injury.

Clinical and research notes indicate that GPX2 contributes to the balance between cell protection and cancer biology. In some contexts, higher GPX2 levels may help cells cope with reactive oxygen species and may influence tumor growth or resistance to therapy, whereas reduced GPX2 activity can increase susceptibility to oxidative damage. Consequently, GPX2 is studied as a biomarker of redox status and as a factor in diseases involving oxidative stress, especially in the gastrointestinal tract.