The elastin receptor shows structural and functional similarities to the 67-kDa tumor cell laminin receptor

Abstract

Laminin- and elastin-binding proteins were isolated by ligand affinity chromatography from plasma membranes of fetal bovine auricular chondroblasts and human A2058 melanoma cells. From both cell types, a 67-kDa protein was identified which bound to either elastin or laminin affinity resins. Structural and functional similarities between the elastin and laminin-binding proteins were suggested by 1) cross-reactivity between antibodies directed against the two proteins; 2) elution of the laminin receptor from laminin columns with soluble elastin peptides; and 3) modulation of substrate binding by galactoside sugars. In addition, extraction properties indicate that both receptors are peripheral membrane proteins whose association with the cell surface is mediated by their lectin properties. Mapping of the binding site on laminin suggests that the 67-kDa chondroblast receptor interacts with a hydrophobic elastin-like sequence in domain V of the B1 chain, and chemotaxis studies indicate that cell migration to elastin peptides and laminin involves the same receptor.