Ral GTPases regulate neurite branching through GAP-43 and the exocyst complex

Authors:
Lalli G, Hall A
In:
Source: J Cell Biol
Publication Date: (2005)
Issue: 171(5): 857-69
Research Area:
Neurobiology
Cells used in publication:
Neuron, hippo/cortical, rat
Species: rat
Tissue Origin: brain
Platform:
Nucleofector® I/II/2b
Abstract
Neurite branching is essential for the establishment of appropriate neuronal connections during development and regeneration. We identify the small GTPase Ral as a mediator of neurite branching. Active Ral promotes neurite branching in cortical and sympathetic neurons, whereas Ral inhibition decreases laminin-induced branching. In addition, depletion of endogenous Ral by RNA interference decreases branching in cortical neurons. The two Ral isoforms, RalA and -B, promote branching through distinct pathways, involving the exocyst complex and phospholipase D, respectively. Finally, Ral-dependent branching is mediated by protein kinase C-dependent phosphorylation of 43-kD growth-associated protein, a crucial molecule involved in pathfinding, plasticity, and regeneration. These findings highlight an important role for Ral in the regulation of neuronal morphology.