Cell adhesion molecules of the immunoglobulin superfamily in the nervous system

Abstract

Cell adhesion molecules (CAMs) are proteins mediating cell-cell or cell-extracellular matrix (ECM) interactions. CAMs are traditionally divided into four groups, the cadherins, the selectins, the integrins and CAMs belonging to the immunoglobulin superfamily (IgSF). The present chapter describes CAMs belonging to IgSF, that exclusively or in part, are expressed in the nervous system. The chapter includes descriptions of myelin protein zero (P0), integrin-associated protein (CD47), neuroplastin, activated leukocyte-cell adhesion molecule (ALCAM), melanoma cell adhesion molecule (MCAM), myelin-associated glycoprotein (MAG), the neural cell adhesion molecules 1 and 2 (NCAM, NCAM2), Down Syndrome cell adhesion molecule (DSCAM) and Down Syndrome cell adhesion molecule-like-1(DSCAML1), sidekick 1 and 2 (SDK1, SDK2), signal-regulatory proteins (SIRPs), nectins, nectin-like proteins (necls), and members of the CTX, IgLON, Robo, contactin, and L1 families. The individual descriptions include sections describing the expression, isoforms, structure, posttranslational modifications, homo- and heterophilic binding partners, signaling and functions of the individual CAMs. The chapter demonstrates CAMs to be more than simple regulators of adhesion. Many CAMs are important mediators of intracellular signal transduction, and CAMs are involved in many biological phenomena including migration, proliferation, and differentiation of cells, as well as axonal guidance, neurite outgrowth, and synaptic plasticity and maturation. © 2007 Springer-Verlag US.