Plexin A2 is a coreceptor for SEMA3A and is necessary for signaling by class 3 semaphorins and subsequent remodeling of the cytoskeleton. This coreceptor plays a role in axon guidance, invasive growth and cell migration. Class 3 semaphorins bind to a complex composed of a neuropilin and a plexin in which the plexin modulates the affinity of the complex for specific semaphorins, and its cytoplasmic domain is required for the activation of down-stream signaling events in the cytoplasm.