Structure and function of Cadherin extracellular regions

Abstract

Cell-surface glycoproteins of the cadherin superfamily are defined by the presence of extracellular cadherin (EC) β-sandwich domains in their extracellular regions. EC domains adopt a fold similar to immunoglobulin domains, but most EC domains ligate calcium through stereotyped sites positioned between successive domains; Ca2+-binding at these sites rigidifies cadherin extracellular regions. Although the superfamily is highly diverse and may serve numerous functions, the best-characterized members are the vertebrate “classical” cadherins, which mediate cell-cell adhesion via homodimerization between their membrane-distal EC1 domains. Nonclassical and invertebrate cadherins have evolved distinct mechanisms for cell recognition and adhesion, and are only now beginning to be understood.