Table 1.

Redox active selenoproteins, their location and main functions.

Selenoprotein	Location	Main Function	References
GPx1	cell cytosol and mitochondria	reduces peroxides to water	[11]
GPx2	gastrointestinal tract, liver	reduces free hydroperoxides of fatty acid and hydrogene peroxide	[12]
GPx3	plasma and extracellular fluid, kidneys	perform antioxidant function in plasma	[11,12]
GPx4	cell cytosol and cell membranes, testis	reduces lipid hydroperoxides, participates in ferroptosis (iron–based cell death)	[11,12]
TRx1	cytosol of liver, kidney, bone, heart cells	reduces thioredoxins	[12]
TRx2	mitochondria	reduces thioredoxins	[11]
TRx3	testis	reduces thioredoxins	[11]
SelP	plasma, extracellular compartment	storage and transport of Se from liver to other tissues	[12]
SelF	endoplasmic reticulum of liver, prostate, T-cells	possesses oxidoreductase activity, regulates protein folding	[11]
SelS	endoplasmic reticulum	regulates cellular redox balance	[40]
SelM	endoplasmic reticulum	regulates protein folding	[11]