Molecular mapping of functional domains of the leukocyte receptor for endothelium, LAM-1

Détails

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Version: Final published version
Licence: CC BY-NC-SA 4.0
ID Serval
serval:BIB_49AFE3D20FDD
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Molecular mapping of functional domains of the leukocyte receptor for endothelium, LAM-1
Périodique
Journal of Cell Biology
Auteur⸱e⸱s
Kansas  G. S., Spertini  O., Stoolman  L. M., Tedder  T. F.
ISSN
0021-9525 (Print)
Statut éditorial
Publié
Date de publication
07/1991
Volume
114
Numéro
2
Pages
351-358
Langue
anglais
Notes
Journal Article Research Support, U.S. Gov't, P.H.S. --- Old month value: Jul
Résumé
The human lymphocyte homing receptor LAM-1, like its murine counterpart MEL-14, functions as a mammalian lectin, and mediates the binding of leukocytes to specialized high endothelial cells in lymphoid organs (HEV). LAM-1 is a member of a new family of cell adhesion molecules, termed selectins or LEC-CAMs, which also includes ELAM-1 and PAD-GEM (GMP-140/CD62). To localize the regions of LAM-1 that are involved in cell adhesion, we developed chimeric selectins, in which various domains of PAD-GEM were substituted into LAM-1, and used these chimeric proteins to define the domain requirements for carbohydrate binding, and to localize the regions recognized by several mAb which inhibit the adhesion of lymphocytes to lymph node HEV. The binding of PPME or fucoidin, soluble complex carbohydrates that specifically define the lectin activity of LAM-1 and MEL-14, required only the lectin domain of LAM-1. The LAM1-1, LAM1-3, and LAM1-6 mAb each strongly inhibit the binding of lymphocytes to HEV in the in vitro frozen section assay, and defined three independent epitopes on LAM-1. Blocking of PPME or fucoidin binding by LAM1-3 indicated that this site is identical, or in close proximity, to the carbohydrate binding site, and analysis of the binding of LAM1-3 to chimeric selectins showed that the epitope detected by LAM1-3 is located within the lectin domain. Although the LAM1-6 epitope is also located in the lectin domain, LAM1-6 did not affect the binding of PPME or fucoidin. The LAM1-1 epitope was located in, or required, the EGF domain, and, importantly, binding of LAM1-1 significantly enhanced the binding of both PPME and fucoidin. These results suggest that adhesion mediated by LAM-1 may involve cooperativity between functionally and spatially distinct sites, and support previous data suggesting a role for the EGF domain of LAM-1 in lymphocyte adhesion to HEV.
Mots-clé
Amino Acid Sequence Animals Antibodies, Monoclonal/immunology Anticoagulants/metabolism B-Lymphocytes/metabolism/ultrastructure Carbohydrate Metabolism Cell Adhesion/physiology Cell Adhesion Molecules/*genetics/metabolism/physiology Cell Line Chimera/genetics/physiology *Chromosome Mapping DNA/genetics Endothelium, Vascular/metabolism/physiology/*ultrastructure Epitopes L-Selectin Lectins/metabolism Leukocytes/metabolism/physiology/*ultrastructure Mannans/metabolism Mice Molecular Sequence Data P-Selectin Plant Lectins Platelet Membrane Glycoproteins/genetics/metabolism/physiology Polysaccharides/metabolism Receptors, Leukocyte-Adhesion/*genetics/metabolism/physiology
Pubmed
Web of science
Open Access
Oui
Création de la notice
25/01/2008 15:31
Dernière modification de la notice
20/08/2019 13:57
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