Cell differentiation in Dictyostelium discoideum controls assembly of protein-linked glycans.
The prestalk and prespore cells from the Dictyostelium discoideum multicellular slug stage of development differ in assembly of glycoconjugates. Prespore cells are 2- to 3-fold more active than prestalk cells in the assembly of N-linked glycans and 20-fold more active in their fucosylation. Only prespore cells synthesize an O-linked glycan consisting in part of Fuc alpha-linked to N-acetylglucosamine. Incorporation of fucose, glucosamine, mannose and galactose into large pronase-resistant glycoconjugates was almost exclusively into prespore cells. Such glucosamine-labelled glycoconjugates resist fragmentation by beta-elimination and include a glycoantigen dependent on the modB genetic locus. In contrast, large fucose-labelled glycoconjugates consisted of multiple, small, O-linked oligosaccharides on carrier peptides. The spore coat protein SP96 has several fucosylated O-linked oligosaccharides, one of which correlates with a fucose epitope previously shown to localize in prespore vesicles and the outer layer of the spore coat.
Riley
G R
GR
Department of Biology, Georgetown University, Washington, DC 20057.
West
C M
CM
Henderson
E J
EJ
D000818:Animals; D001894:Borohydrides; D002236:Carbohydrate Conformation; D002454:Cell Differentiation / Q000502:physiology; D004023:Dictyostelium / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D005643:Fucose / Q000032:analysis / Q000378:metabolism; D005656:Fungal Proteins / Q000096:biosynthesis; D005690:Galactose / Q000378:metabolism; D005944:Glucosamine / Q000378:metabolism; D006001:Glycoconjugates / Q000096:biosynthesis; D006023:Glycoproteins / Q000378:metabolism; D008358:Mannose / Q000378:metabolism; D011134:Polysaccharides / Q000096:biosynthesis*
D001894:Borohydrides; D005656:Fungal Proteins; D006001:Glycoconjugates; D006023:Glycoproteins; D011134:Polysaccharides; D005643:Fucose; D005944:Glucosamine; D008358:Mannose; D005690:Galactose