Medical College of Wisconsin
CTSICores SearchResearch InformaticsREDCap

N-Glycosylation is required for Na+-dependent vitamin C transporter functionality. Biochem Biophys Res Commun 2008 Sep 12;374(1):123-7

Date

07/16/2008

Pubmed ID

18619416

Pubmed Central ID

PMC2528843

DOI

10.1016/j.bbrc.2008.06.120

Scopus ID

2-s2.0-47749122550   33 Citations

Abstract

The human sodium-dependent vitamin C transporters (hSVCT1 and hSVCT2) mediate cellular uptake of ascorbic acid. Both these transporters contain potential sites for N-glycosylation in their extracellular domains (Asn-138, Asn-144 [hSVCT1]; Asn-188, Asn-196 [hSVCT2]), however the role of N-glycosylation in transporter function is unexplored. On the basis of the result that tunicamycin decreased (14)C-ascorbic acid uptake in HepG2 cells, we systematically ablated all consensus N-glycosylation sites in hSVCT1 and hSVCT2 to resolve any effects on ascorbic acid uptake, transporter expression and targeting. We show that removal of individual N-glycosylation sites significantly impairs protein expression and consequently ascorbic acid uptake for hSVCT1 mutants (N138Q is retained intracellularly) and for hSVCT2 mutants (all of which reach the cell surface). N-Glycosylation is therefore essential for vitamin C transporter functionality.

Author List

Subramanian VS, Marchant JS, Reidling JC, Said HM

Author

Jonathan S. Marchant PhD Chair, Professor in the Cell Biology, Neurobiology and Anatomy department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Ascorbic Acid
Biological Transport
Cell Line
Cell Membrane
Glycosylation
Humans
Mutation
Organic Anion Transporters, Sodium-Dependent
Protein Structure, Secondary
Sodium-Coupled Vitamin C Transporters
Symporters
Tunicamycin
jenkins-FCD Prod-482 91ad8a360b6da540234915ea01ff80e38bfdb40a