RT Journal Article
SR Electronic
T1 The human concentrative nucleoside transporter-3 Cys602Arg (hCNT3C602R) variant shows impaired sorting to lipid rafts and altered specificity for nucleoside-derived drugs
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP mol.110.063552
DO 10.1124/mol.110.063552
A1 Ekaitz Errasti-Murugarren
A1 Miriam Molina-Arcas
A1 Francisco Javier Casado
A1 Marcal Pastor-Anglada
YR 2010
UL http://molpharm.aspetjournals.org/content/early/2010/04/26/mol.110.063552.abstract
AB hCNT3C602R, a recently identified human concentrative nucleoside transporter 3 (hCNT3) variant, has been shown to interact with natural nucleosides with apparent Km values similar to those of the wild-type transporter, although binding of one of the two sodium ions required for nucleoside translocation is impaired, resulting in decreased Vmax values (Errasti-Murugarren et al., 2008). We have further analyzed the properties of this hCNT3 variant by determining its localization in plasma membrane lipid domains and its interaction with nucleoside-derived drugs used in anticancer and antiviral therapies. When heterologously expressed in HeLa cells, wild-type hCNT3 localized to both lipid raft and non-lipid raft domains. Treatment of cells with the cholesterol-depleting agent methyl-β-cyclodextrin (MβCD) resulted in a marked decrease in hCNT3-related transport activity that was associated with the loss of wild-type hCNT3 from lipid rafts. Interestingly, although exogenously expressed hCNT3C602R was present in non-lipid raft domains at a level similar to that of the wild-type transporter, the mutant transporter was present at much lower amounts in lipid rafts. A substrate profile analysis showed that interactions with a variety of nucleoside-derived drugs were altered in the hCNT3C602R variant, and revealed that sugar hydroxyl residues are key structural determinants for substrate recognition by the hCNT3C602R variant.The American Society for Pharmacology and Experimental Therapeutics