. Interactions of leukocytes with platelets and endothelium may be fundamental events that link the hemostatic and inflammatory responses to tissue injury. GMP-140, a membrane glycoprotein of platelet and endothelial cell secretory granules, is rapidly redistributed to the plasma membrane during cellular activation, where it serves as an inducible receptor for neutrophils and monocytes. GMP-140, along with ELAM-1 and the Mel 14/Leu 8 antigen, comprise the selectin family of cell surface molecules that mediate interactions of leukocytes with other blood or vascular cells. Each selectin contains an N-terminal domain homologous to Ca2+-dependent lectins, followed by an EGF-like domain, a variable number of consensus repeats similar to those in complement-binding proteins, a transmembrane domain, and a short cytoplasmic tail. The lectin and EGF domains of the selectins show particularly striking sequence homology. We have found that the lectin domain of GMP-140 is involved in neutrophil recognition and that this interaction is modulated by at least two divalent-cations binding sites. We postulate that; (1) the EGF-like domain enhances the binding affinity and specificity of the lectin domain for leukocytes; (2) separate functionally relevant binding sites for divalent cations reside on both the lectin and EGF domains, and (3) oligosaccharides comprise part of the receptor on leukocytes that interacts with the lectin domain of GMP-140. We propose to; (1) correlate divalent cation-dependent conformational changes in GMP-140 with ability of the protein to bind to neutrophils; (2) Perform detailed structure-function analyses of the individually expressed lectin and EGF-like domains and characterize potential interactions between the domains; (3) Isolate and characterize the leukocyte receptor for GMP-140. These studies should advance our understanding of the molecular basis for interactions of leukocytes with platelets and endothelium and may provide one of the first examples of a biologically significant, highly specific recognition event between a cell surface lectin and a cell surface oligosaccharide.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL045510-04
Application #
2222191
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
1991-01-15
Project End
1995-12-31
Budget Start
1994-01-01
Budget End
1994-12-31
Support Year
4
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of Oklahoma Health Sciences Center
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
937727907
City
Oklahoma City
State
OK
Country
United States
Zip Code
73117
Cummings, R D (1999) Structure and function of the selectin ligand PSGL-1. Braz J Med Biol Res 32:519-28
Mehta, P; Patel, K D; Laue, T M et al. (1997) Soluble monomeric P-selectin containing only the lectin and epidermal growth factor domains binds to P-selectin glycoprotein ligand-1 on leukocytes. Blood 90:2381-9
Weyrich, A S; Elstad, M R; McEver, R P et al. (1996) Activated platelets signal chemokine synthesis by human monocytes. J Clin Invest 97:1525-34
Laszik, Z; Jansen, P J; Cummings, R D et al. (1996) P-selectin glycoprotein ligand-1 is broadly expressed in cells of myeloid, lymphoid, and dendritic lineage and in some nonhematopoietic cells. Blood 88:3010-21
Patel, K D; Nollert, M U; McEver, R P (1995) P-selectin must extend a sufficient length from the plasma membrane to mediate rolling of neutrophils. J Cell Biol 131:1893-902
Norman, K E; Moore, K L; McEver, R P et al. (1995) Leukocyte rolling in vivo is mediated by P-selectin glycoprotein ligand-1. Blood 86:4417-21
Weyrich, A S; McIntyre, T M; McEver, R P et al. (1995) Monocyte tethering by P-selectin regulates monocyte chemotactic protein-1 and tumor necrosis factor-alpha secretion. Signal integration and NF-kappa B translocation. J Clin Invest 95:2297-303
McEver, R P; Moore, K L; Cummings, R D (1995) Leukocyte trafficking mediated by selectin-carbohydrate interactions. J Biol Chem 270:11025-8
Patel, K D; Moore, K L; Nollert, M U et al. (1995) Neutrophils use both shared and distinct mechanisms to adhere to selectins under static and flow conditions. J Clin Invest 96:1887-96
Wilkins, P P; Moore, K L; McEver, R P et al. (1995) Tyrosine sulfation of P-selectin glycoprotein ligand-1 is required for high affinity binding to P-selectin. J Biol Chem 270:22677-80

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