The integrin beta subunit.

The integrin family of cell adhesion receptors plays a fundamental role in the processes involved in cell division, differentiation and movement. The extracellular domains of integrin alpha/beta heterodimers mediate cell-matrix and cell-cell contacts while their cytoplasmic tails associate with the cytoskeleton. Integrins are capable of transducing information in a bidirectional manner and the beta subunit is now recognised to play an important role in this process. Recent studies have led to the identification of a ligand-binding region on the beta subunit similar to that already characterised on some alpha subunits, and sequences in the cytoplasmic tails of the beta subunits that interact with cytoskeletal and signalling components. Adhesive events can also play a role in the progression of all four major classes of human disease--neoplastic, inflammatory, traumatic and infectious--and the specific nature of integrin adhesion mechanisms make them an attractive target for therapy.