Ligand Binding to Integrins: Dynamic Regulation and Common Mechanisms

Cell-cell and cell-substratum adhesive interactions regulate aggregation, cell polarity, and cell migration. In addition, such interactions can influence the differentiation of cells as manifested by changes in cell morphology, proliferation, and gene expression programs (Menko and Boettiger 1987; Ruoslahti and Pierschbacher 1987; Panayotou et al. 1989). This paper focuses on the integrins, a broadly distributed family (virtually every cell type expresses integrins, even erythrocyte precursors) of adhesion receptors. The existence of this family was first suspected in the mid 1980s (Ginsberg et al. 1985) because of the functional similarities among recognition specificities of cell adhesion receptors. This suspicion was heightened by the identification of gross structural (Pytela et al. 1986) and immunologic (Plow et al. 1986; Ginsberg et al. 1987) similarities among adhesion receptors. The cloning and sequencing of many of the members of this family (Tamkun et al. 1986; Argraves et al. 1987; Fitzgerald et al. 1987; Kishimoto et...