A novel cell binding site in the coiled-coil domain of laminin involved in capillary morphogenesis.
Recently, we reported the isolation and characterization of an anti-laminin antibody that modulates the extracellular matrix-dependent morphogenesis of endothelial cells. Here we use this antibody to precisely map the binding site responsible for mediating this biologically important interaction. By using a phage display-assisted mapping strategy to preserve protein structure, we demonstrate for the first time that the coiled-coil region of laminin contains a cell binding site. The adhesion motif is formed by residues contributed by both alpha and gamma chains, and is located in the middle part of the rod-like portion in a highly flexible area, which corresponds to a protease-susceptible site. Based on this information, a peptide mimotope was used to characterize the cognate receptor. Although we can not rule out the implication of other receptors, our results demonstrate that the laminin helical rod active site interacts with alpha2beta1 integrin on the surface of endothelial cells. These findings provide new insight into the complex mechanisms regulating capillary morphogenesis.
Sanz
Laura
L
Department of Immunology, Hospital Universitario Clínica Puerta de Hierro, 28035 Madrid.
García-Bermejo
Laura
L
Blanco
Francisco J
FJ
Kristensen
Peter
P
Feijóo
Mónica
M
Suárez
Eduardo
E
Blanco
Belén
B
Alvarez-Vallina
Luis
L
D000595:Amino Acid Sequence; D000906:Antibodies / Q000276:immunology; D001665:Binding Sites; D002196:Capillaries / Q000254:growth & development*; D002448:Cell Adhesion / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D006801:Humans; D038982:Integrin alpha2beta1 / Q000276:immunology; D007797:Laminin / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009024:Morphogenesis; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
D000906:Antibodies; D038982:Integrin alpha2beta1; D007797:Laminin; D011994:Recombinant Proteins