Crosstalk between cell adhesion molecules and the semaphorin/neuropilin/Plexin signalling

Abstract

Signalling by cell adhesion molecules (IgCAMs) plays diverse and fundamental roles in the formation, maturation and function of the nervous system. Investigations of their mechanisms of action during early steps of the wiring of neuronal circuits uncovered a contribution of the L1CAM subgroup of IgCAMs in axonal responses to Class 3 Semaphorins (Sema3s), which are secreted in vertebrates. L1CAMs were found to interact with Neuropilins (NRPs), the ligand-binding moiety of Sema3 receptor complexes. As such, L1-NRP cis interactions were shown to be required for some Sema3s to elicit a neuronal guidance response, while trans interactions were found to regulate the nature of the response. From these initial findings, additional contributions and molecular interplay with the Semaphorin signalling have been characterized, which expand the physiological and pathological contexts in which IgCAM/Semaphorin crosstalk might contribute.