Metalloproteases: carving out a role in axon guidance.

Two families of metalloproteases, the matrix metalloproteases (MMPs) and the A Disintegrin and Metalloproteases (ADAMs), have recently been implicated in the formation of neural connections in the developing central nervous system. Invertebrate and vertebrate axons fail to extend and/or make pathfinding errors when metalloprotease function is inhibited or absent. Culture studies suggest that this requirement for metalloprotease activity results from their ability to cleave ligands, or their receptors, so as to activate or inhibit specific axon extension or guidance signaling pathways.