Selenoprotein family (SELENOs)

Selenoproteins are a specialized group of 25 human proteins characterized by the co-translational incorporation of selenocysteine, often referred to as the 21st amino acid, in response to a recoded UGA stop codon (Labunskyy et al., 2014). These proteins primarily function as essential enzymes, particularly oxidoreductases, that play critical roles in maintaining cellular redox balance and protecting tissues from oxidative damage (Reeves & Hoffmann, 2009). Major families within this group include the glutathione peroxidases (GPXs), which neutralize reactive oxygen species, and the thioredoxin reductases (TXNRDs), which regulate the redox state of thioredoxin and other cellular substrates (Arner & Holmgren, 2000). Dysregulation of selenoprotein expression or activity is linked to various pathologies, including cancer, cardiovascular disease, and neurodegeneration, making them significant therapeutic targets (Zhang et al., 2019). In oncology, drugs like auranofin are used to inhibit TXNRD, thereby increasing oxidative stress and inducing apoptosis in malignant cells. Conversely, selenium supplements like sodium selenite are used to support overall selenoprotein synthesis in deficiency states, though clinical application is limited by a narrow therapeutic window; excessive intake can lead to selenosis, a form of selenium toxicity (Vinceti et al., 2014).

Other names

SelenoproteinsSelenium-containing proteinsHuman selenoproteomeSe-containing proteins

Modulation of cellular redox homeostasis through the provision of selenium as a substrate for protein synthesis or the targeted inhibition of specific selenoprotein enzymes, such as thioredoxin reductase, to induce oxidative stress in pathological cells.