Signal transduction by GPI-anchored receptors in the nervous system

A particularly intriguing role in communication within the nervous system is played by glycosyl phosphatidylinositol (GPI)-anchored glycoproteins. Although our understanding of how neuronal GPI-linked molecules transduce signals is still in its infancy, it is now possible to assemble a tentative model to describe their functioning. Shared features of these otherwise diverse receptors will be outlined, with particular emphasis given to the exclusively GPI-anchored contactin/F11 subgroup of the immunoglobulin superfamily. Contactin/F11 itself, with five extracellular ligands and an intracellular pathway involving Fyn, serves to illustrate the wide range of signalling possible through this group of receptors.