ABSTRACT
The extracellular matrix provides cells with a structural and mechanical scaffold and critical information. Determination of the highly complex composition of the extracellular matrix began first with the purification of the constitutive molecules and was later accelerated by the development of molecular biology techniques allowing identification and characterization of new full-length polypeptides which have not been purified from tissues. The major extracellular matrix components are collagens, non-collagenous glycoproteins, and proteoglycans. Most of these molecules are chimaeras sharing one or more different structural domains and evolve from the combination of a relatively small repertoire of genes. Interactions studies with authentic or genetically engineered molecules and fragments have led to the realization that extracellular matrix components are organized into precisely ordered architectures. Gene targetting and identification of molecular defects in aquired or inherited human diseases have highlighted the pivotal and indispensable role of several components of the extracellular matrix in development and homeostasis.
