Engelsk definition
The prototypical and most well-studied member of the semaphorin family. Semaphorin-3A is an axon-repulsive guidance cue for migrating neurons in the developing nervous system. It has so far been found only in vertebrates, and binds to NEUROPILIN-1/plexin complex receptors on growth cones. Like other class 3 semaphorins, it is a secreted protein.