Molecular cloning and characterization of a novel isoform of the human UDP-galactose transporter, and of related complementary DNAs belonging to the nucleotide-sugar transporter gene family.
We described recently the molecular cloning of human UDP-galactose transporter 1 (hUGT1) [Miura, N. et al. (1996) J. Biochem. 120, 236-241]. Now we have characterized its isoform, hUGT2, that is most likely generated through the alternative splicing of a transcript derived from the UGT genomic gene, that also codes for hUGT1. Introduction of the open reading frame sequence of hUGT2 into a mouse cell line, Had-1, that lacks the UDP-galactose transporter, complemented the genetic defect of the mutant, as judged from the lectin-sensitivity spectra of the transformants and the nucleotide-sugar transporting activity of microsomal vesicles isolated from them. UGT-related genes were found through a BLAST search of dbEST based on their significant similarity with hUGT genes. We report here cDNA clones belonging to two subfamilies of the nucleotide-sugar transporter gene family. One is the human CMP-sialic acid transporter gene, and the other is a group of homologous genes with an undefined function that are distributed in man, mouse, and rat, and show significant similarity to the yeast UDP-N-acetylglucosamine transporter.
Ishida
N
N
Department of Physiological Chemistry, Tokyo Metropolitan Institute of Medical Science (Rinshoken).
Miura
N
N
Yoshioka
S
S
Kawakita
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry; D006801:Humans; D008099:Liver / Q000737:chemistry; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D051381:Rats; D012984:Software; D014531:Uridine Diphosphate Galactose / Q000378:metabolism*; D000099237:UDP-Galactose Translocators
D002352:Carrier Proteins; D018076:DNA, Complementary; D009004:Monosaccharide Transport Proteins; D014531:Uridine Diphosphate Galactose; D000099237:UDP-Galactose Translocators