Abstract
Nucleotide-sugar transporters are crucial components in the synthesis of glycoconjugates. We identified a novel human nucleotide-sugar transporter gene, hfrc1, which is homologous to Drosophila melanogaster fringe connection, Caenorhabditis elegans sqv-7, and human UGTrel7. HFRC1 was localized within the Golgi apparatus following its transient expression in HCT116 cells. In human tissues, hfrc1 and UGTrel7 exhibited similar tissue distributions, although hfrc1 transcripts showed a 10 times greater abundance than those of UGTrel7. The heterologous expression of HFRC1 in the yeast revealed the multisubstrate specific transport activity of HFRC1 (for UDP-N-acetylglucosamine (UDP-GlcNAc), UDP-glucose (UDP-Glc), and GDP-mannose (GDP-Man), with apparent K(m) values of 8.0, 2.1, and 0.14 microm, respectively). In the mammalian cells, HFRC1 transported UDP-GlcNAc and UDP-Glc, but not GDP-Man. Overexpression of the hfrc1 gene in HCT116 cells modulated the cell surface heparan sulfate expression status. These results suggest that HFRC1 takes part in the synthesis of heparan sulfate by regulating the level of UDP-GlcNAc, a donor substrate for the heparan sulfate synthases.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Amino Acid Sequence
-
Animals
-
Biological Transport
-
Blotting, Western
-
Carrier Proteins / chemistry*
-
Carrier Proteins / genetics*
-
Cell Line
-
Cloning, Molecular
-
DNA, Complementary / metabolism
-
Dose-Response Relationship, Drug
-
Drosophila Proteins / chemistry*
-
Drosophila Proteins / genetics*
-
Flow Cytometry
-
Genetic Vectors
-
Glucosamine / analogs & derivatives*
-
Glucosamine / metabolism
-
Golgi Apparatus / metabolism
-
Guanosine Diphosphate / metabolism
-
Heparitin Sulfate / chemistry
-
Heparitin Sulfate / metabolism*
-
Humans
-
Kinetics
-
Mannose / metabolism
-
Membrane Transport Proteins / biosynthesis*
-
Membrane Transport Proteins / chemistry
-
Membrane Transport Proteins / genetics*
-
Microscopy, Fluorescence
-
Models, Genetic
-
Molecular Sequence Data
-
Monosaccharide Transport Proteins / chemistry*
-
Monosaccharide Transport Proteins / genetics
-
Nucleotide Transport Proteins*
-
Nucleotides / chemistry
-
Phylogeny
-
Reverse Transcriptase Polymerase Chain Reaction
-
Sequence Homology, Amino Acid
-
Subcellular Fractions
-
Substrate Specificity
-
Tissue Distribution
-
Transfection
Substances
-
Carrier Proteins
-
DNA, Complementary
-
Drosophila Proteins
-
Frc protein, Drosophila
-
Membrane Transport Proteins
-
Monosaccharide Transport Proteins
-
Nucleotide Transport Proteins
-
Nucleotides
-
SLC35D1 protein, human
-
SLC35D2 protein, human
-
Guanosine Diphosphate
-
UDP-glucosamine
-
Heparitin Sulfate
-
Glucosamine
-
Mannose