Human Mutations in SLC2A9 (Glut9) Affect Transport Capacity for Urate.

Détails

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Etat: Public
Version: Final published version
Licence: CC BY 4.0
ID Serval
serval:BIB_A7AF8FC6F949
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Human Mutations in SLC2A9 (Glut9) Affect Transport Capacity for Urate.
Périodique
Frontiers in physiology
Auteur(s)
Ruiz A., Gautschi I., Schild L., Bonny O.
ISSN
1664-042X (Print)
ISSN-L
1664-042X
Statut éditorial
Publié
Date de publication
2018
Peer-reviewed
Oui
Volume
9
Pages
476
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: epublish
Résumé
SLC2A9 or Glut9 is a voltage sensitive urate transporter, mainly expressed in the kidneys, the liver, and the intestine. Human Glut9 loss-of-function mutations were identified in familial hypouricemia, and several single nucleotide polymorphisms (SNPs) were associated with lower serum urate, further indicating that Glut9 is a major determinant of serum uric acid level. To get insights in Glut9 transport characteristics, we systematically analyzed the function of known human Glut9 mutants using <sup>14</sup> C-urate uptake assay and two-electrode voltage clamp (TEVC) in the <i>Xenopus laevis</i> oocyte expression system. Surface expression was assessed by immunostaining and biotinylation. We found decreased urate transport by flux studies for most of the variants. No variant was permissive for glucose transport. We could further differentiate two behaviors among the mutants: those harboring poor overall and cell-surface expression leading to low activity and those fully expressed at the cell surface, but presenting decreased activity. We studied the latter by TEVC and observed, in depolarized conditions, decreased inward currents measured in presence of 400 μM urate, partially reversed in 1 mM urate. In addition, we showed that C210F displays lower transport ability. By contrast, N333S showed decreased urate transport activity and urate affinity, suggesting that it may belong to the urate binding pocket. Systematic analysis of Glut9 mutants confirms Glut9 as putative target for the treatment of hyperuricemia and brings new insights in Glut9 structure - function.
Mots-clé
SLC2A9, site directed mutagenesis, structure-function relationships, transporters, uric acid
Pubmed
Web of science
Open Access
Oui
Création de la notice
09/07/2018 16:56
Dernière modification de la notice
20/08/2019 15:12
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