Molecular cloning and characterization of beta1,4-N-acetylgalactosaminyltransferases IV synthesizing N,N'-diacetyllactosediamine

FEBS Lett. 2004 Mar 26;562(1-3):134-40. doi: 10.1016/S0014-5793(04)00219-4.


A sequence highly homologous to beta1,4-N-acetylgalactosaminyltransferase III (beta4GalNAc-T3) was found in a database of human expressed sequence tags. The full-length open reading frame of the gene, beta4GalNAc-T4 (GenBank accession number AB089939), was cloned using the 5' rapid amplification of cDNA ends method. It encodes a typical type II transmembrane protein of 1039 amino acids having 42.6% identity with beta4GalNAc-T3. The recombinant enzyme transferred N-acetylgalactosamine to N-acetylglucosamine-beta-benzyl with a beta1,4-linkage to form N,N'-diacetyllactosediamine as did beta4GalNAc-T3. In specificity toward oligosaccharide acceptor substrates, it was quite similar to beta4GalNAc-T3 in vitro, however, the tissue distributions of the two enzymes were quite different. These results indicated that the two enzymes have similar roles in different tissues.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Carbohydrate Sequence
  • Cell Line
  • Cloning, Molecular
  • Disaccharides / biosynthesis*
  • Humans
  • Lactose / analogs & derivatives*
  • Lactose / biosynthesis*
  • Molecular Sequence Data
  • N-Acetylgalactosaminyltransferases / genetics
  • N-Acetylgalactosaminyltransferases / metabolism*
  • Sequence Alignment
  • Substrate Specificity
  • Tissue Distribution


  • Disaccharides
  • N-acetylgalactosaminyl-1-4-N-acetylglucosamine
  • B4GALNT4 protein, human
  • N-Acetylgalactosaminyltransferases
  • (N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase
  • Lactose

Associated data

  • GENBANK/AB089939
  • GENBANK/AB114827