Human placental Na+-dependent multivitamin transporter. Cloning, functional expression, gene structure, chromosomal localization

Haiping Wang, Wei Huang, You Jun Fei, Hong Xia, Teresa L. Yang-Feng, Frederick H. Leibach, Lawrence D Devoe, Vadivel Ganapathy, Puttur D Prasad

Research output: Contribution to journalArticle

114 Scopus citations

Abstract

We have cloned the human Na+-dependent multivitamin transporter (SMVT), which transports the water-soluble vitamins pantothenate, biotin, and lipoate, from a placental choriocarcinoma cell line (JAR). The cDNA codes for a protein of 635 amino acids with 12 transmembrane domains and 4 putative sites for N-linked glycosylation. The human SMVT exhibits a high degree of homology (84% identity and 89% similarity) to the rat counterpart. When expressed in HRPE cells, the cDNA-induced transport process is obligatorily dependent on Na+ and accepts pantothenate, biotin, and lipoate as substrates. The relationship between the cDNA-specific uptake rate of pantothenate or biotin and Na+ concentration is sigmoidal with a Na+:vitamin stoichiometry of 2:1. The human SMVT, when expressed in Xenopus laevis oocytes, induces inward currents in the presence of pantothenate, biotin, and lipoate in a Na+-, concentration-, and potential-dependent manner. We also report here on the structural organization and chromosomal localization of the human SMVT gene. The SMVT gene is ~14 kilobase pairs in length and consists of 17 exons. The SMVT gene is located on chromosome 2p23 as evidenced by somatic cell hybrid analysis and fluorescence in situ hybridization.

Original languageEnglish (US)
Pages (from-to)14875-14883
Number of pages9
JournalJournal of Biological Chemistry
Volume274
Issue number21
DOIs
StatePublished - May 21 1999

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Human placental Na<sup>+</sup>-dependent multivitamin transporter. Cloning, functional expression, gene structure, chromosomal localization'. Together they form a unique fingerprint.

  • Cite this