The role of cell adhesion molecules for navigating axons: Density matters

Cell adhesion molecules of the immunoglobulin-super-family (IgSF-CAMs) do not only have a physical effect, mediating merely attachment between cell surfaces. For navigating axons, IgSF-CAMs also exert an instructive impact: Upon activation, they elicit intracellular signalling cascades in the tip of the axon, the growth cone, which regulate in a spatio-temporally concerted action both speed and direction of the axon. Density and distribution of IgSF-CAMs in the growth cone plasma membrane play important roles for the activation of IgSF-CAMs, their clustering, and the adhesive forces they acquire, as well as for the local restriction and effective propagation of their intracellular signals.

► The relevance of IgSF-CAMs for growing and navigating axons. ► The dual role of IgSF-CAMs, mediating adhesion and eliciting signalling. ► The importance of IgSF-CAM interactions with the cytoskeleton. ► The impact of IgSF-CAM spacing/density on various axonal functions. ► The homo- and heterophilic interactions of IgSF-CAM (table, schematic).