Necessary for signaling by class 3 semaphorins and subsequent remodeling of the cytoskeleton. Plays a role in axon guidance, neuronal growth cone collapse and cell migration (By similarity). Homotetramer and heterotetramer. Expressed in the prospective neuroectoderm at the end of gastrulation. During open neural plate stages, expressed broadly throughout the anterior neural plate and in the three bilateral stripes of the posterior neural plate where primary neurons arise. At tadpole stages, expression is maintained throughout the central nervous system and in the eye retina. Expressed zygotically from the end of gastrulation. Expression increases during neurula stages and is maintained at a constant level throughout tailbud stages and later development. By the neuronal determination factor neurog2/X-ngngr-1. Repressed by Notch signaling. Belongs to the metallo-dependent hydrolases superfamily. Hydantoinase/dihydropyrimidinase family. Lacks most of the conserved residues that are essential for binding the metal cofactor and hence for dihydropyrimidinase activity. Its enzyme activity is therefore unsure.