| SelP, N terminus | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | SelP_N | ||||||||
| Pfam | PF04592 | ||||||||
| Pfam clan | CL0172 | ||||||||
| InterPro | IPR007671 | ||||||||
| |||||||||
| SelP, C terminus | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | SelP_C | ||||||||
| Pfam | PF04593 | ||||||||
| InterPro | IPR007672 | ||||||||
| |||||||||
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. [1] This particular protein contains two domains: the C terminal and N terminal domain. The N-terminal domain is larger than the C terminal [2] and the N-terminal is thought to be glycosylated. [3] The human version is SEPP1.
SelP may have antioxidant properties. It can attach to epithelial cells, and may protect vascular endothelial cells against peroxynitrite toxicity. [1] The high selenium content of SelP suggests that it may be involved in selenium intercellular transport or storage. [3] The promoter structure of bovine SelP suggests that it may be involved in countering heavy metal intoxication, and may also have a developmental function. [4]
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. [3] 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. [3]
N-terminal domain allows conservation of whole body selenium and appears to supply selenium to the kidney. [5]
The structure of the N-terminal domain is larger and contains less Selenium. However it is thought to be heavily glycosylated. [5]
The function of the C-terminal domain is known to be vital for maintaining levels of selenium in brain and testis tissue but not for the maintenance of whole-body selenium. [5]
The C-terminal domain is smaller in size but far more rich in selenium. [5]
Binds to heparin in a pH-dependent manner [2]