Characterization of the 5' regulatory region of the human sodium-dependent multivitamin transporter, hSMVT.
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.
Dey
Sanjit
S
Veterans Affairs Medical Center, Los Angeles, CA 90073, USA.
Subramanian
Veedamali S
VS
Chatterjee
Nabendu S
NS
Rubin
Stanley A
SA
Said
Hamid M
HM
D001483:Base Sequence; D001710:Biotin / Q000378:metabolism; D018938:Caco-2 Cells; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D003001:Cloning, Molecular; D005091:Exons; D017930:Genes, Reporter; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010205:Pantothenic Acid / Q000378:metabolism; D011401:Promoter Regions, Genetic; D027981:Symporters; D008063:Thioctic Acid / Q000378:metabolism
D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D027981:Symporters; C119981:biotin transporter; D010205:Pantothenic Acid; D001710:Biotin; D008063:Thioctic Acid