Selenoprotein P (SeP)

Selenoprotein P is a secreted, selenium-rich plasma glycoprotein encoded by the SELENOP gene and characterized by the presence of ten selenocysteine residues—one in the N-terminal domain (redox motif, antioxidant activity) and nine in the C-terminal region (selenium transport/storage)[1][3][4][5][6][7][9]. It serves essential functions as the principal transporter of selenium to various tissues, notably brain, testis, and kidney, maintaining selenium homeostasis and protecting cells from oxidative stress. Selenoprotein P also binds multiple metal ions, possibly conferring resistance to heavy metal toxicity. Its plasma levels are clinically used as a biomarker for nutritional selenium status. Genetically, loss of function or deficiency of SeP leads to neurological, reproductive, and immune disorders in mice, underlining its critical physiological role[5][7]. SeP interacts with specific receptors (ApoER2, megalin) to mediate tissue uptake of selenium. There are currently no approved drugs directly targeting SeP; current therapeutics involve selenium donor compounds for deficiency states[4]. Monitoring and manipulating selenium levels must be conducted with care due to tight systemic regulation and potential toxicity.

Other names

SELENOPSEPP1SELPSeP

Selenium donor or supplement: increasing substrate availability for SeP, targeting selenium deficiency; Metal ion chelation/competition: sequestration or binding of toxic metals; modulating oxidative stress via metal-binding