The widespread effect of beta 1,4-galactosyltransferase on N-glycan processing

Arch Biochem Biophys. 2001 Aug 1;392(1):79-86. doi: 10.1006/abbi.2001.2421.


We investigated beta 1,4-GalT (UDP-galactose: beta-d-N-acetylglucosaminide beta 1,4-galactosyltransferase) in terms of intracellular competition with GnT-IV (UDP-N-acetylglucosamine: alpha1,3-d-mannoside beta1,4-N-acetylglucosaminyltransferase) and GnT-V (UDP-N-acetylglucosamine: alpha1,6-d-mannoside beta 1,6-N-acetylglucosaminyltransferase). The beta 1,4-GalT-I gene was introduced into Chinese hamster ovary (CHO) cells producing human interferon (hIFN)-gamma (IM4/V/IV cells) and five clones expressing various levels of beta 1,4-GalT were isolated. As we previously reported, parental IM4/V/IV cells express high levels of GnT-IVa and -V and produce hIFN-gamma having primarily tetraantennary sugar chains. The branching of sugar chains on hIFN-gamma was suppressed in the beta 1,4-GalT-enhanced clones to a level corresponding to the intracellular activity of beta 1,4-GalT relative to GnTs. Moreover, the contents of hybrid-type and high-mannose-type sugar chains increased in these clones. The results showed that beta 1,4-GalT widely affects N-glycan processing by competing with GnT-IV, GnT-V, and alpha-mannosidase II in cells and also by some other mechanisms that suppress the conversion of high-mannose-type sugar chains to the hybrid type.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CHO Cells
  • Carbohydrate Sequence
  • Chromatography, High Pressure Liquid
  • Cricetinae
  • Humans
  • Interferon-gamma / biosynthesis
  • Interferon-gamma / chemistry
  • Interferon-gamma / genetics
  • Mannose / chemistry
  • Mannosidases / metabolism
  • Molecular Sequence Data
  • N-Acetylglucosaminyltransferases / metabolism
  • N-Acetyllactosamine Synthase / genetics
  • N-Acetyllactosamine Synthase / metabolism*
  • Polysaccharides / chemistry
  • Polysaccharides / metabolism*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • alpha-Mannosidase


  • Polysaccharides
  • Recombinant Proteins
  • Interferon-gamma
  • N-Acetylglucosaminyltransferases
  • alpha-1,3-mannosylglycoprotein beta-1,4-N-acetylglucosaminyltransferase
  • alpha-1,6-mannosylglycoprotein beta 1,6-N-acetylglucosaminyltransferase
  • N-Acetyllactosamine Synthase
  • Mannosidases
  • alpha-Mannosidase
  • Mannose