Agrin isoforms and their role in synaptogenesis

Agrin is thought to mediate the motor neuron-induced aggregation of
synaptic proteins on the surface of muscle fibers at neuromuscular
junctions. Recent experiments provide direct evidence in support of
this hypothesis, reveal the nature of agrin immunoreactivity at
sites other than neuromuscular junctions, and have resulted in
findings that are consistent with the possibility that agrin plays
a role in synaptogenesis throughout the nervous system.