Functional Roles for Integrin Subunit Cytoplasmic Domains

Cell-surface receptors in the integrin family mediate a wide variety of dynamic cell adhesion processes, such as those involved during complex tissue organizing events, immunolocalization of leukocytes, and tumor cell growth and metastasis. The integrin family comprises at least 20 distinct αβ heterodimers, with αβ subunit combinations as shown in Figure 1. This diversity of heterodimeric structures, many with multiple ligand-binding specificities, facilitates cell adhesion to a variety of extracellular matrix ligands, cell-surface pr-teins, and some serum and complement proteins (Hemler 1990; Larson and Springer 1990; Hynes 1992).