Actin molecules promote neurite outgrowth of chick telencephalic neurons in vitro

Chick brain extract contains protein factors for neurite outgrowth from embryonic chick telencephalic neurons in dissociated cell cultures. In the course of purification of the factors using a bioassay system, a 41 kDa protein was detected to be one of the factors. Immunoblot analysis showed that this protein is identical to actin. In addition, G-actin purified from rabbit skeletal muscle exhibits neurite outgrowth activity in the same dose-dependent manner as the 41 kDa protein. The same bioassay carried with other purified proteins did not show such a remarkable activity.