Lamp-1 does not acquire the large polylactosaminoglycans characteristic of F9 cells.
Although F9 cells labelled with [3H]glucosamine synthesize many glycoproteins that bind to Datura stramonium agglutinin-agarose, only a small proportion of these were immunoprecipitated with monoclonal antibodies to lamp-1 and lamp-2 (lamp = lysosomal membrane protein). Differentiation of F9 cells by retinoic acid increased labelling of all Datura stramonium-bound glycoproteins, including lamp-1 and lamp-2. Although the large polylactosaminoglycans excluded from Bio-Gel P-6 that are characteristic of F9 cells were obtained from total glycoproteins, little of these large polylactosaminoglycans was found on lamp-1 and lamp-2. There was no increase in large polylactosaminoglycans of lamp-1 and lamp-2 after retinoic acid treatment, but an increase in the size of small polylactosaminoglycans (included on Bio-Gel P-6) and tri- and tetra-antennary complex oligosaccharides. Therefore, other factors besides the expression of specific glycosyltransferases determine the extent of elongation of polylactosaminoglycans on lysosomal membrane proteins.
Romero
P A
PA
McGill Cancer Centre, McGill University, Montréal, Québec, Canada.
Way
T
T
Herscovics
A
A
D000606:Amino Sugars; D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D002240:Carbohydrate Sequence; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D002846:Chromatography, Affinity; D013286:Datura stramonium; D004591:Electrophoresis, Polyacrylamide Gel; D005944:Glucosamine / Q000378:metabolism; D006020:Glycopeptides / Q000302:isolation & purification; D006023:Glycoproteins / Q000096:biosynthesis* / Q000302:isolation & purification; D037102:Lectins; D051907:Lysosomal Membrane Proteins; D008247:Lysosomes / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000302:isolation & purification; D051379:Mice; D008969:Molecular Sequence Data; D037121:Plant Lectins; D010946:Plants, Medicinal; D010947:Plants, Toxic; D013724:Teratoma; D014212:Tretinoin / Q000494:pharmacology; D014316:Tritium; D014407:Tumor Cells, Cultured
D000606:Amino Sugars; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; C041384:Datura stramonium lectin; D006020:Glycopeptides; D006023:Glycoproteins; D037102:Lectins; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins; D037121:Plant Lectins; D014316:Tritium; C032233:lactosamine; D014212:Tretinoin; D005944:Glucosamine