Multiple Binding Sites in Collagen Type I for the Integrins α1β1 and α2β1 *

By Yi Xu, S. Gurusiddappa, R. Rich, R. Owens, D. Keene, R. Mayne, A. Höök, M. Höök. Journal of Biological Chemistry, 2000

216 citations recorded by the source corpus.

Integrins α1β1 and α2β1 are two major collagen receptors on the surface of eukaryotic cells. Binding to collagen is primarily due to an A-domain near the N terminus of the α chains. Previously, we reported that recombinant A-domain of α1β1(α1A) had at least two affinity classes of binding sites in type I collagen (Rich, R. L., et al. (1999)J. Biol. Chem. 274, 24906–24913). Here, we compared the binding of the recombinant A-domain of α2β1 (α2A) to type I collagen with that of α1A using surface plasmon resonance and showed that α2A exhibited only one detectable class of binding sites in type I collagen, with a K D of ∼10 μm at ∼3 binding sites per collagen molecule. We further demonstrated that α1A and α2A competed with each other for binding to type I collagen in enzyme-linked immunosorbent assay (ELISA), suggesting that the binding sites in collagen for the two A-domains overlap or are adjacent to each other. By using rotary shadowing, the complexes of α1A- and α2A-procollagen were visualized. Morphometric analyses indicated three major binding regions (near the N terminus, in the central part, and near the C terminus) along the type I procollagen molecule for both A-domains. The positions of the respective binding regions for α1A and α2A were overlapping with or adjacent to each other, consistent with the ELISA results. Analysis of the sequences of type I collagen revealed that GER or GER-like motifs are present at each of the binding regions, and notably, the central region contains the GFOGER sequence, which was previously identified as a high affinity site for both α1A and α2A (Knight, C. G., et al. (2000) J. Biol. Chem. 275, 35–40). Peptides containing GLOGERGRO (peptide I, near the N terminus), GFOGERGVQ (peptide II, central), and GASGERGPO (peptide III, near the C terminus) were synthesized. Peptides I and II effectively inhibited the binding of α1A and α2A to type I collagen, while peptide III did so moderately. The N-terminal site in type I collagen has the sequence GLOGER in all three chains. Thus, it seems that peptide I represents a newly discovered native high affinity site for α1A and α2A.

Subfields: Biomaterials, Cancer Research, Immunology and Allergy

View Paper: https://www.semanticscholar.org/paper/b8bcd56e1ac6771985da808de410987ae723d865

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Citations in the corpus

Consortium for osteogenesis imperfecta mutations in the helical domain of type I collagen: regions rich in lethal mutations align with collagen binding sites for integrins and proteoglycans (2007, background): “…in the α1(I) chain without known mutations contains eight glycine residues (helical position 484–505), and includes one of the three sequences in the triple helix proposed to mediate the binding of the α1β1/α2β1 integrins [Xu et al., 2000], the major cell surface receptors for type I collagen.”
Collagen self-assembly and the development of tendon mechanical properties. (2003, background): “Eukaryotic cells directly attach to extracellular matrix collagen fibers via integrin subunits a1b1 and a1b2 (Xu et al., 2000) through a six-residue sequence (glycine– phenylalanine–hydroxyproline–glycine–glutamic acid– arginine) sequence (Knight et al.”
Revealing Early Steps of α2β1 Integrin-mediated Adhesion to Collagen Type I by Using Single-Cell Force Spectroscopy (2007, background): “There are several high-affinity bindings sites for 2 1 on fibrillar collagen type I (Knight et al., 2000; Xu et al., 2000).”