Molecular and functional characterization of the intestinal Na+-dependent multivitamin transporter.

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Prasad PD, Wang H, Huang W, Fei YJ, Leibach FH, Devoe LD, Ganapathy V

Molecular and functional characterization of the intestinal Na+-dependent multivitamin transporter.

Arch Biochem Biophys. 1999 Jun 1;366(1):95-106.

PubMed ID

10334869 [ View in PubMed

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Abstract

We have cloned a Na+-dependent multivitamin transporter from rabbit intestine (riSMVT). The cDNA codes for a protein of 636 amino acids with 12 putative transmembrane domains. When expressed in mammalian cells, the cDNA induces Na+-dependent uptake of the vitamins pantothenate and biotin. Lipoate is also a substrate for the cDNA-induced uptake process. The affinity constant for the cDNA-specific transport of pantothenate and biotin is approximately 2 and approximately 8 microM, respectively. The Na+:vitamin stoichiometry is greater than 1, indicating that the transport process is electrogenic. The SMVT-specific transcripts of 3.2 kbp are equally distributed throughout the small intestine. We have also cloned SMVT from the human intestinal cell line Caco-2. The Caco-2 SMVT cDNA codes for a protein of 635 amino acids which is homologous to riSMVT and is identical to the SMVT expressed in the human choriocarcinoma cell line JAR. Caco-2 SMVT also catalyzes Na+-dependent uptake of pantothenate, biotin, and lipoate. In oocytes expressing Caco-2 SMVT, all three vitamins evoke inward currents, confirming the electrogenicity of the transport process.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Lipoic acid	Sodium-dependent multivitamin transporter	Protein	Humans	Unknown	Not Available	Details

Polypeptides

Name	UniProt ID
Sodium-dependent multivitamin transporter	Q9Y289	Details