Matrix in signal transduction and growth factor modulation.

The extracellular matrix (ECM) is indispensable for the survival of multicellular organisms. It provides the adherent cells with crucial clues for migration, proliferation and differentiation. These clues are transmitted to the interior of the cell by ECM receptors like the integrins. Signaling by the ECM occurs by induction of assembly and disassembly of cytoskeletal structures or by modulation of classical signal transduction pathways such as activation of phosphatidylinositol-proteases, growth factors and cytokines that are specifically bound to its constituents and thereby stored, localized and modulated in terms of their biological activities. Finally, both the quantity and the quality of growth factor signaling appear to be dependent on the temporal and spatial activation of ECM receptors, supporting the requirement of a crosstalk between matrix and growth factor receptors.