Polarized expression of members of the solute carrier SLC19A gene family of water-soluble multivitamin transporters: implications for physiological function.

Department of Pharmacology, 321 Church Street SE, University of Minnesota Medical School, MN 55455, USA.
Biochemical Journal (Impact Factor: 4.78). 12/2003; 376(Pt 1):43-8. DOI: 10.1042/BJ20031220
Source: PubMed

ABSTRACT Humans lack biochemical pathways for the synthesis of the micro-nutrients thiamine and folate. Cellular requirements are met through membrane transport activity, which is mediated by proteins of the SLC19A gene family. By using live-cell confocal imaging methods to resolve the localization of all SLC19A family members, we show that the two human thiamine transporters are differentially targeted in polarized cells, establishing a vectorial transport system. Such polarization decreases functional redundancy between transporter isoforms and allows for independent regulation of thiamine import and export pathways in cells.

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