The glycosphingolipids (GSL) form part of eukaryotic cell membranes. They consist of a hydrophilic carbohydrate moiety linked to a hydrophobic ceramide tail embedded within the lipid bilayer of the membrane. Lactosylceramide, Gal1,4Glc1Cer (LacCer), is the common synthetic precursor to the majority of GSL found in vertebrates. Alpha 1.4-glycosyltransferases utilise UDP donors and transfer the sugar to a beta-linked acceptor. This region appears to be confined to higher eukaryotes. No function has been yet assigned to this region [1].

1: Cloning of Gb3 synthase, the key enzyme in globo-series glycosphingolipid synthesis, predicts a family of alpha 1, 4-glycosyltransferases conserved in plants, insects, and mammals. Keusch JJ, Manzella SM, Nyame KA, Cummings RD, Baenziger JU; J Biol Chem 2000;275:25315-25321. PMID:10854428