Abstract
E- and P-selectin are inducible cell adhesion molecules on endothelial cells, which function as Ca2+-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 Ca2+-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 Ca2+-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.
Original language | English |
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Pages (from-to) | 471-481 |
Number of pages | 11 |
Journal | Journal of Cell Biology |
Volume | 125 |
Issue number | 2 |
DOIs | |
Publication status | Published or Issued - Apr 1994 |
Externally published | Yes |
ASJC Scopus subject areas
- Cell Biology