Monospecific and common glycoprotein ligands for E- and P-selectin on myeloid cells.
E- and P-selectin are inducible cell adhesion molecules on endothelial cells, which function as Ca(2+)-dependent lectins and mediate the binding of neutrophils and monocytes. We have recently identified a 150-kD glycoprotein ligand for E-selectin on mouse myeloid cells, using a recombinant antibody-like form of mouse E-selectin. Here, we report that this ligand does not bind to an analogous P-selectin fusion protein. Instead, the chimeric P-selectin-IgG protein recognizes a 160-kD glycoprotein on the mouse neutrophil progenitor 32D cl 3, on mature mouse neutrophils and on human HL60 cells. The binding is Ca(2+)-dependent and requires the presence of sialic acid on the ligand. This P-selectin-ligand is not recognized by E-selectin. Removal of N-linked carbohydrate side chains from the 150-kD and the 160-kD monospecific selectin ligands abolishes the binding of both ligands to the respective selectin. Treatment of HL60 cells with Peptide: N-glycosidase F inhibited cell binding to P- and E-selectin. In addition, glycoproteins of 230 and 130 kD were found on mature mouse neutrophils, which bound both to E- and P-selectin in a Ca(2+)-dependent fashion. The signals detected for these ligands were 15-20-fold weaker than those for the monospecific ligands. Both proteins were heavily sialylated and selectin-binding was blocked by removal of sialic acid, but not by removal of N-linked carbohydrates. Our data reveal that E- and P-selectin recognize two categories of glycoprotein ligands: one type requires N-linked carbohydrates for binding and is monospecific for each of the two selectins and the other type binds independent of N-linked carbohydrates and is common for both endothelial selectins.
Lenter
M
M
Hans Spemann Laboratory, Max Planck Institute for Immunology, Freiburg, Germany.
Levinovitz
A
A
Isenmann
S
S
Vestweber
D
D
D000581:Amidohydrolases / Q000378:metabolism; D000818:Animals; D050260:Carbohydrate Metabolism; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D019040:E-Selectin; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology / Q000378:metabolism; D007951:Leukemia, Myeloid / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008024:Ligands; D008666:Metalloendopeptidases / Q000378:metabolism; D051379:Mice; D009504:Neutrophils / Q000378:metabolism; D019007:P-Selectin; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D010980:Platelet Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism*; D051381:Rats; D012794:Sialic Acids / Q000378:metabolism; D014407:Tumor Cells, Cultured
D015815:Cell Adhesion Molecules; D019040:E-Selectin; D006023:Glycoproteins; D007074:Immunoglobulin G; D008024:Ligands; D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins; D012794:Sialic Acids; D008666:Metalloendopeptidases; C070738:O-sialoglycoprotein endopeptidase; D000581:Amidohydrolases; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase