Rho family GTPases as key regulators for neuronal network formation

Rho family GTPases act as transducers of signals from extracellular stimuli to the cytoskeleton and gene expression. Their actions are temporal and spatial determinants for cellular functions. The cellular functions of Rho family GTPases have been studied in fibroblasts and endothelial cells, and recent advances have revealed their roles in the regulation of neuronal network formation, including migration, neurite outgrowth, po-larity, axon guidance, dendrite maturation and synapse formation. In addition, a signifi-cant number of X-linked mental retardation genes have been shown to encode compo-nents directly involved in signal transduction pathways of Rho family GTPases, underscoring the view that Rho family GTPases essentially participate in the neuronal network formation. In this review, we will overview current understanding of the func-tions of Rho family GTPases in neuronal network formation. Key words; G protein, neuron, neuronal network, Rho. Rho family GTPases as molecular switches Small GTPases of the Rho family are key regulators of the actin cytoskeleton in eukaryotic cells from yeast t