The present invention relates to eukaryotic host cells having modified oligosaccharides which may be modified further by
heterologous expression of a set of glycosyltransferases,
sugar transporters and mannosidases to become host-strains for the production of mammalian, e.g., human therapeutic glycoproteins. The process provides an engineered host
cell which can be used to express and target any desirable
gene(s) involved in
glycosylation. Host cells with modified lipid-linked oligosaccharides are created or selected. N-glycans made in the engineered host cells exhibit GnTIII activity, which produce bisected N-
glycan structures and may be modified further by
heterologous expression of one or more enzymes, e.g., glycosyltransferases,
sugar transporters and mannosidases, to yield human-like glycoproteins. For the production of therapeutic proteins, this method may be adapted to engineer
cell lines in which any desired
glycosylation structure may be obtained.