PMID: 20007810
Authors:
Brondijk TH, de Ruiter T, Ballering J, Wienk H, Lebbink RJ, van Ingen H, Boelens R, Farndale RW, Meyaard L, Huizinga EG
Title:
Crystal structure and collagen-binding site of immune inhibitory receptor LAIR-1: unexpected implications for collagen binding by platelet receptor GPVI.
Journal:
Blood. 2010 Feb 18;115(7):1364-73. Epub 2009 Dec 10.
Abstract:
Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1), one of the most widely spread immune receptors, attenuates immune cell activation when bound to specific sites in collagen. The collagen-binding domain of LAIR-1 is homologous to that of glycoprotein VI (GPVI), a collagen receptor crucial for platelet activation. Because LAIR-1 and GPVI also display overlapping collagen-binding specificities, a common structural basis for collagen recognition would appear likely. Therefore, it is crucial to gain insight into the molecular interaction of both receptors with their ligand to prevent unwanted cross-reactions during therapeutic intervention. We determined the crystal structure of LAIR-1 and mapped its collagen-binding site by nuclear magnetic resonance (NMR) titrations and mutagenesis. Our data identify R59, E61, and W109 as key residues for collagen interaction. These residues are strictly conserved in LAIR-1 and GPVI alike; however, they are located outside the previously proposed GPVI collagen-binding site. Our data provide evidence for an unanticipated mechanism of collagen recognition common to LAIR-1 and GPVI. This fundamental insight will contribute to the exploration of specific means of intervention in collagen-induced signaling in immunity and hemostasis.