FUNCTION OF MYOSIN-V IN FILOPODIAL EXTENSION OF NEURONAL GROWTH CONES

The molecular mechanisms underlying directed motility of growth cones have not been determined, The role of myosin-V, an unconventional myos in, in growth cone dynamics was examined by chromophore-assisted laser inactivation (CALI), CALI of purified chick brain myosin-V absorbed o nto nitrocellulose-coated cover slips inhibited the ability of myosin- V to translocate actin filaments. CALI of myosin-V in growth cones of chick dorsal root ganglion neurons resulted in rapid filopodial retrac tion, The rate of filopodial extension was significantly decreased, wh ereas the rate of filopodial retraction was not affected, which sugges ts a specific role for myosin-V in filopodial extension.