Characterization of the 5' regulatory region of the human sodium-dependent multivitamin transporter, hSMVT

Biochim Biophys Acta. 2002 Mar 19;1574(2):187-92. doi: 10.1016/s0167-4781(02)00226-9.

Abstract

We cloned and functionally characterized the 5' regulatory region of the human sodium-dependent multivitamin transporter (hSMVT) gene, a remarkably versatile carrier responsible for uptake of biotin, pantothenic acid and lipoate. Two potential transcriptional start sites were determined by 5'-RACE and found to be at -4603, and -4303. Two distinct promoters (P1 and P2) were identified. Both putative promoter sequences were TATA-less, CAAT-less, contained highly GC-rich sites, and had multiple putative regulatory cis-elements (e.g., AP1, AP2, C/EBP, SP1, NF1, and GATA). The activities of the putative promoters were confirmed using a firefly luciferase reporter gene assay system following transient transfection into three cultured human cell lines: Caco-2, HEK293, and vascular smooth muscle cells. The minimal region required for basal activity of the hSMVT promoter was also determined by generating a series of deletion constructs and found to be encoded by a sequence between -5846 to -5313 for P1 and between -4417 to -4244 for P2 relative to the translation initiation codon. These results demonstrate the first molecular characterization of the regulatory region of this important human gene.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Base Sequence
  • Biotin / metabolism
  • Caco-2 Cells
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Cell Line
  • Cloning, Molecular
  • Exons
  • Genes, Reporter
  • Humans
  • Membrane Glycoproteins / genetics*
  • Membrane Glycoproteins / metabolism
  • Molecular Sequence Data
  • Pantothenic Acid / metabolism
  • Promoter Regions, Genetic
  • Symporters*
  • Thioctic Acid / metabolism

Substances

  • Carrier Proteins
  • Membrane Glycoproteins
  • Symporters
  • biotin transporter
  • Pantothenic Acid
  • Biotin
  • Thioctic Acid