Chapter 9 - Cell Adhesion Molecules

Abstract

Publisher Summary Cell adhesion molecules are cell-surface proteins that account for cell-to-cell and/or cell-to-extracellular matrix (ECM) interactions. Cell adhesion molecules act at the cell surface where they interact with the molecules that are expressed on an opposing cell surface or are present in the ECM. Therefore, they engage in trans interactions with either identical molecules termed “homophilic interactions” or with different molecules termed “heterophilic interactions.” In the nervous system, cell adhesion molecules are shown to play critical roles in all facets of nervous system development and maintenance, and many cell adhesive mechanisms between many different types of cells. Cell adhesion molecules are divided into four major groups or “superfamilies”: the immunoglobulin superfam­ily of cell adhesion molecules (IgCAMs), the cadherins, the integrins (Figs. 9-7, 9-8), and the superfamily of C-type lectin-like domain proteins (CTLDs). Of these IgCAMs, cadherins, and integrins are functionally implicated in a number of processes in the nervous system while CTLDs are primarily charac­terized in the immune system. CTLDs contain the so-called carbohydrate-recognition domain (CRD) of calcium-depen­dent (C-type) carbohydrate binding proteins (lectins) or a domain highly homologous to it.