MATRIX IN SIGNAL-TRANSDUCTION AND GROWTH-FACTOR MODULATION

The extracellular matrix (ECM) is indispensable for the survival of mu lticellular organisms. It provides the adherent cells with crucial clu es for migration, proliferation and differentiation. These clues are t ransmitted to the interior of the cell by ECM receptors like the integ rins. Signaling by the ECM occurs by induction of assembly and disasse mbly of cytoskeletal structures or by modulation of classical signal t ransduction pathways such as activation of phosphatidylinositol-phosph ate kinase. Furthermore, the ECM plays a major role as a reservoir for morphoregulatory proteases, growth factors and cytokines that are spe cifically bound to its constituents and thereby stored, localized and modulated in terms of their biological activities. Finally, both the q uantity and the quality of growth factor signaling appear to be depend ent on the temporal and spatial activation of ECM receptors, supportin g the requirement of a crosstalk between matrix and growth factor rece ptors.