Identification and functional characterization of the first nucleobase transporter in mammals: implication in the species difference in the intestinal absorption mechanism of nucleobases and their analogs between higher primates and other mammals.

ABSTRACT: Nucleobases are important compounds that constitute nucleosides and nucleic acids. Although it has long been suggested that specific transporters are involved in their intestinal absorption and uptake in other tissues, none of their molecular entities have been identified in mammals to date. Here we describe identification of rat Slc23a4 as the first sodium-dependent nucleobase transporter (rSNBT1). The mRNA of rSNBT1 was expressed highly and only in the small intestine. When transiently expressed in HEK293 cells, rSNBT1 could transport uracil most efficiently. The transport of uracil mediated by rSNBT1 was sodium-dependent and saturable with a Michaelis constant of 21.2 microM. Thymine, guanine, hypoxanthine, and xanthine were also transported, but adenine was not. It was also suggested b

SUBMITTER: Yamamoto S 

PROVIDER: S-EPMC2825448 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature