cDNA cloning, expression, and chromosomal localization of human N-acetylglucosaminyltransferase III (GnT-III).
UDP-N-acetylglucosamine:beta-D-mannoside beta 1,4 N-acetylglucosaminyltransferase III (GnT-III) [EC 2.4.1.144] catalyzes the addition of N-acetylglucosamine in beta 1-4 linkage to the beta-linked mannose of the trimannosyl core of N-linked sugar chains to produce a bisecting GlcNAc residue. We have isolated six independent cDNA clones of human GnT-III from a fetal liver cDNA library. The cDNA sequence has an open reading frame that predicts a protein of 531 amino acids. The homology to rat GnT-III is 86% at the nucleotide level and is 91% at the amino acid level. The amino-terminal transmembrane domain and the catalytic domain are well conserved in the two species. Human GnT-III has a deletion of four amino acids in the "neck" region and several differences in the COOH-terminal region compared with the rat sequence. Using one of the human cDNA clones as the probe, two overlapping genomic clones have been isolated from a human cosmid library. The GnT-III gene has been mapped to chromosome 22q.13.1 using fluorescence in situ hybridization.
Ihara
Y
Y
Department of Biochemistry, Osaka University Medical School.
Nishikawa
A
A
Tohma
T
T
Soejima
H
H
Niikawa
N
N
Taniguchi
N
N
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D002892:Chromosomes, Human, Pair 22; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics*; D015870:Gene Expression; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics*; D051381:Rats; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
D004247:DNA; D017351:N-Acetylglucosaminyltransferases; C054599:beta-1,4-mannosyl-glycoprotein beta-1,4-N-acetylglucosaminyltransferase