Sodium-dependent vitamin C transporter

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Sodium-dependent vitamin C transporter
Properties of human protein
Mass / length primary structure 598 amino acids
Secondary to quaternary structure multipass (11 TMS) membrane protein
Isoforms 3
Identifier
Gene name SLC23A1
External IDs
Transporter classification
TCDB 2.A.40.6.1
designation Nucleobase / ascorbate transporter (NAT)
Occurrence
Homology family SLC23A
Parent taxon Euteleostomi

The sodium-dependent vitamin C transporters are proteins in the cell membrane of vertebrate cells that catalyze the introduction of sodium ions and vitamin C into the cell . So they are transport proteins . In humans there are two of these transporters, named SVCT1 and SVCT2 , which are encoded by the genes SLC23A1 and SLC23A2 . SVCT1 occurs particularly in the small intestine , kidneys , ovaries , colon and liver , while SVCT2 has no specific localization.

The transport equation is:

Ascorbate (outside) + 2Na + (outside)     ascorbate (inside) + 2Na + (inside)

So it is a symport .

Variants of SVCT2 may be associated with the occurrence of colorectal cancer. In addition to sodium, SVCT2 appears to be dependent on calcium or magnesium. This is still the subject of current research.

Individual evidence

  1. ↑ UniProt Q9UHI7
  2. ↑ TCDB : 2.A.40
  3. ↑ Mackenzie B, Illing AC, Hediger MA: Transport model of the human Na + -coupled L-ascorbic acid (vitamin C) transporter SVCT1 . In: Am. J. Physiol., Cell Physiol. . 294, No. 2, February 2008, pp. C451-9. doi : 10.1152 / ajpcell.00439.2007 . PMID 18094143 .
  4. ↑ Erichsen HC, Peters U, Eck P, et al : Genetic variation in sodium-dependent vitamin C transporters SLC23A1 and SLC23A2 and risk of advanced colorectal adenoma . In: Nutrition and Cancer . 60, No. 5, 2008, pp. 652-9. doi : 10.1080 / 01635580802033110 . PMID 18791929 .
  5. ↑ Godoy A, Ormazabal V, Moraga-Cid G, et al : Mechanistic insights and functional determinants of the transport cycle of the ascorbic acid transporter SVCT2. Activation by sodium and absolute dependence on bivalent cations . In: Journal of Biological Chemistry . 282, No. 1, January 2007, pp. 615-24. doi : 10.1074 / jbc.M608300200 . PMID 17012227 .

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