CELL ADHESION MOLECULES

Several major families of cell adhesion molecules can be distinguished. These include the cadherins and N-CAM’s, which play a crucial role in cell recognition and adhesion, while integrins are implicated in the adherence of cells to the extracellular matrix.

Cadherins constitute a family of proteins, the members of which are differentially expressed in the different tissues. One of the best characterized members is E-cadherin, which is prevalent in epithelial tissues. It has been shown to play a crucial role in the process of tumor cell metastasis. NCAM’s (neural cell adhesion molecules) exist in at least three forms of plasma membrane plycoproteins, which are expressed in a variety of tissues including most nerve cells.

The integrins, finally, form a large family of glycosylated transmembrane proteins that act as dimers of an a- and a ß-subunit in interconnecting the cytoskeleton and the extracellular matrix.