Expression of natural human b1,4-GalT1 variants and of non-mammalian homologues in plants leads to differences in galactosylation of N-glycans

T. Hesselink, G.J.A. Rouwendal, M.G.L. Henquet, D.E.A. Florack, J.P.F.G. Helsper, H.J. Bosch

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7 Citations (Scopus)


b1,4-Galactosylation of plant N-glycans is a prerequisite for commercial production of certain biopharmaceuticals in plants. Two different types of galactosylated N-glycans have initially been reported in plants as the result of expression of human b1,4-galactosyltransferase 1 (GalT). Here we show that these differences are associated with differences at its N-terminus: the natural short variant of human GalT results in hybrid type N-glycans, whereas the long form generates bi-antennary complex type N-glycans. Furthermore, expression of non-mammalian, chicken and zebrafish GalT homologues with N-termini resembling the short human GalT N-terminus also induce hybrid type N-glycans. Providing both non-mammalian GalTs with a 13 amino acid N-terminal extension that distinguishes the two naturally occurring forms of human GalT, acted to increase the levels of biantennary galactosylated N-glycans when expressed in tobacco leaves. Replacement of the cytosolic tail and transmembrane domain of chicken and zebrafish GalTs with the corresponding region of rat a2,6-sialyltransferase yielded a gene whose expression enhanced the level of bi-antennary galactosylation even further.
Original languageEnglish
Pages (from-to)717-728
JournalTransgenic Research
Issue number5
Publication statusPublished - 2014



  • golgi-apparatus
  • murine beta-1,4-galactosyltransferase
  • beta 1,4-galactosyltransferase
  • transgenic plants
  • gene
  • cells
  • localization
  • antibodies
  • oligosaccharides
  • glycoproteins

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