INTEGRIN LIGAND INTERACTIONS - A YEAR IN REVIEW

Many cell-cell and cell-matrix interactions depend upon the engagement of specific ligands by members of the integrin family of cell-adhesio n receptors. In concert with the identification of new integrins, the number of integrin ligands continues to expand dramatically. The diver sity of the integrin ligands bridges many areas of cell and molecular biology. Ligand recognition by integrins requires not only the presenc e of the cognate primary sequence within an appropriate secondary stru cture, but also the correct tertiary and quaternary structure of the l igand. Presentation of an 'activated' ligand sequence to specific cont act sites within the integrin under specified divalent-cation conditio ns is necessary for a productive and high-affinity interaction.