COLLAPSIN - A PROTEIN IN BRAIN THAT INDUCES THE COLLAPSE AND PARALYSIS OF NEURONAL GROWTH CONES

Repulsive guidance cues can steer neuronal growth cones during develop ment and prevent mature axons from regenerating. We have identified a 100 kd glycoprotein in the chick brain that is a good candidate for a repulsive cue. Since it induces the collapse and paralysis of neuronal growth cones in vitro, we have named it collapsin. It is effective at concentrations of approximately 10 pM. The C-terminal half of collaps in contains a single immunoglobulin-like domain and an additional high ly basic region. The N-terminal half of collapsin shares significant h omology with fasciclin IV, a growth cone guidance protein in grasshopp er. Recombinant collapsin causes sensory ganglion growth cones to coll apse but not retinal ganglion cell growth cones. We propose that colla psin could serve as a ligand that guides specific growth cones by a mo tility-inhibiting mechanism.