This article highlights recent studies into the roles of the G protein
s in two processes required for axon growth: growth cone motility and
vesicular transport. Heterotrimeric G proteins are involved in growth
cone motility, but their precise roles remain controversial. The small
GTP-binding proteins are clearly established regulators of the actin
cytoskeleton in fibroblasts, and their functions are just beginning to
be explored in the growth cone. Members of the rab subfamily of small
GTP-binding proteins have been shown to regulate vesicular transport
in every cell type examined thus far, including neurons. (C) 1998 Acad
emic Press.