|SelP, N terminus|
|SelP, C terminus|
In molecular biology, the protein domain selenoprotein P (SelP) is the only known eukaryotic selenoprotein that contains multiple selenocysteine (Sec) residues. It is a secreted glycoprotein, often found in the plasma. Its precise function remains to be elucidated however it is thought to have antioxidant properties. This particular protein contains two domains: the C terminal and N terminal domain. The N-terminal domain is larger than the C terminal and the N-terminal is thought to be glycosylated.
SelP may have antioxidant properties. It can attach to epithelial cells, and may protect vascular endothelial cells against peroxynitrite toxicity. The high selenium content of SelP suggests that it may be involved in selenium intercellular transport or storage. The promoter structure of bovine SelP suggests that it may be involved in countering heavy metal intoxication, and may also have a developmental function.
The N-terminal region always contains one Sec residue, and this is separated from the C-terminal region (9-16 Sec residues) by a histidine-rich sequence. The large number of Sec residues in the C-terminal portion of SelP suggests that it may be involved in selenium transport or storage. However, it is also possible that this region has a redox function.
N terminal domain
N-terminal domain allows conservation of whole body selenium and appears to supply selenium to the kidney
C terminal domain
The C-terminal domain is smaller in size but far more rich in selenium.
Binds to herapin in a pH-dependent manner
- Mostert V (April 2000). "Selenoprotein P: properties, functions, and regulation". Arch. Biochem. Biophys. 376 (2): 433–8. doi:10.1006/abbi.2000.1735. PMID 10775431.
- Burk RF; Hill KE (2009). "Selenoprotein P-expression, functions, and roles in mammals". Biochim Biophys Acta. 1790 (11): 1441–7. doi:10.1016/j.bbagen.2009.03.026. PMC 2763998. PMID 19345254.
- Kryukov GV; Gladyshev VN (December 2000). "Selenium metabolism in zebrafish: multiplicity of selenoprotein genes and expression of a protein containing 17 selenocysteine residues". Genes Cells. 5 (12): 1049–60. doi:10.1046/j.1365-2443.2000.00392.x. PMID 11168591.
- Fujii M; Saijoh K; Kobayashi T; Fujii S; Lee MJ; Sumino K (October 1997). "Analysis of bovine selenoprotein P-like protein gene and availability of metal responsive element (MRE) located in its promoter". Gene. 199 (1–2): 211–7. doi:10.1016/S0378-1119(97)00369-7. PMID 9358058.
- Hill KE, Zhou J, Austin LM, Motley AK, Ham AJ, Olson GE, et al. (2007). "The selenium-rich C-terminal domain of mouse selenoprotein P is necessary for the supply of selenium to brain and testis but not for the maintenance of whole body selenium". J Biol Chem. 282 (15): 10972–80. doi:10.1074/jbc.M700436200. PMID 17311913.