Integrins and signal transduction.

Integrin signaling has a critical function in organizing cells in tissues during both embryonic development and tissue repair. Following their binding to the extracellular ligands, the intracellular signaling pathways triggered by integrins are directed to two major functions: organization of the actin cytoskeleton and regulation of cell behaviour induding survival, differentiation and growth. Basic research conducted in the past twelve years has lead to remarkable breakthroughs in this field. Integrins are catalytically inactive and translate positional cues into biochemical signals by direct and/or functional association with intracellular adaptors, cytosolic tyrosine kinases or growth factor and cytolcine receptors. The purpose of this chapter is to highlight recent experimental and conceptual advances in integrin signaling with particular emphasis on the ability of integrins to regulate Fak/Src family lcinases (SFKs) activation and the cross-talk with soluble growth factors receptors and cytokines.