Reaction participants Show >> << Hide
- Name help_outline guanine Identifier CHEBI:16235 (CAS: 73-40-5) help_outline Charge 0 Formula C5H5N5O InChIKeyhelp_outline UYTPUPDQBNUYGX-UHFFFAOYSA-N SMILEShelp_outline C12=C(N=C(NC1=O)N)NC=N2 2D coordinates Mol file for the small molecule Search links Involved in 16 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline Na+ Identifier CHEBI:29101 (CAS: 17341-25-2) help_outline Charge 1 Formula Na InChIKeyhelp_outline FKNQFGJONOIPTF-UHFFFAOYSA-N SMILEShelp_outline [Na+] 2D coordinates Mol file for the small molecule Search links Involved in 259 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:76283 | RHEA:76284 | RHEA:76285 | RHEA:76286 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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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.
Yamamoto S., Inoue K., Murata T., Kamigaso S., Yasujima T., Maeda J.Y., Yoshida Y., Ohta K.Y., Yuasa H.
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 ... >> More
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 by studies of the inhibitory effect on rSNBT1-mediated uracil transport that several nucleobase analogs such as 5-fluorouracil are recognized by rSNBT1, but cytosine and nucleosides are not or only poorly recognized. Furthermore, rSNBT1 fused with green fluorescent protein was mainly localized at the apical membrane, when stably expressed in polarized Madin-Darby canine kidney II cells. These characteristics of rSNBT1 were almost fully in agreement with those of the carrier-mediated transport system involved in intestinal uracil uptake. Therefore, it is likely that rSNBT1 is its molecular entity or at least in part responsible for that. It was also found that the gene orthologous to the rSNBT1 gene is genetically defective in humans. This may have a biological and evolutional meaning in the transport and metabolism of nucleobases. The present study provides novel insights into the specific transport and metabolism of nucleobases and their analogs for therapeutic use. << Less
J Biol Chem 285:6522-6531(2010) [PubMed] [EuropePMC]
This publication is cited by 4 other entries.