Regulators of Rho GTPases in neuronal development

The formation and elaboration of axonal and dendritic morphologies are fundamental aspects of neuronal polarization critical for information processing. In general, developing CNS neurons elaborate one axon and multiple dendrites in response to intracellular and extracellular cues, so as to transmit and receive information, respectively. The molecular mechanisms underlying axon-dendrite polarity are complex and involve the integration of numerous signaling pathways that impinge on the cytoskeleton. One group of proteins, the Rho GTPases, has emerged as key integrators of environmental cues to regulate the underlying axonal and dendritic cytoskeletons. Here, we discuss the role of regulators of the Rac1 GTPase in axon development and highlight the importance of both actin and microtubule remodeling in this process.