Remodeling of the lectin-EGF-like domain interface in P- and L-selectin increases adhesiveness and shear resistance under hydrodynamic force.
Crystal structures of the lectin and epidermal growth factor (EGF)-like domains of P-selectin show 'bent' and 'extended' conformations. An extended conformation would be 'favored' by forces exerted on a selectin bound at one end to a ligand and at the other end to a cell experiencing hydrodynamic drag forces. To determine whether the extended conformation has higher affinity for ligand, we introduced an N-glycosylation site to 'wedge open' the interface between the lectin and EGF-like domains of P-selectin. This alteration increased the affinity of P-selectin for its ligand P-selectin glycoprotein 1 (PSGL-1) and thereby the strength of P-selectin-mediated rolling adhesion. Similarly, an asparagine-to-glycine substitution in the lectin-EGF-like domain interface of L-selectin enhanced rolling adhesion under shear flow. Our results demonstrate that force, by 'favoring' an extended selectin conformation, can strengthen selectin-ligand bonds.
Phan
Uyen T
UT
CBR Institute for Biomedical Research, Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Waldron
Travis T
TT
Springer
Timothy A
TA
D000818:Animals; D002448:Cell Adhesion / Q000276:immunology; D002460:Cell Line; D004815:Epidermal Growth Factor / Q000737:chemistry* / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D019041:L-Selectin / Q000737:chemistry* / Q000276:immunology; D036904:Leukocyte Rolling / Q000276:immunology*; D019007:P-Selectin / Q000737:chemistry* / Q000276:immunology; D020836:Protein Structure, Quaternary; D033081:Shear Strength; D014162:Transfection
D019007:P-Selectin; D019041:L-Selectin; D004815:Epidermal Growth Factor