The function of RhoGTPases in axon ensheathment and myelination.

RhoGTPases are molecular switches that integrate extracellular signals to perform diverse cellular responses. This ability relies on the network of proteins regulating RhoGTPases activity and localization, and on the interaction of RhoGTPases with many different cellular effectors. Myelination is an ideal place for RhoGTPases regulation, as it is the result of fine orchestration of many stimuli from at least two cell types. Recent work has revealed that RhoGTPases are required for Schwann cells to sort, ensheath, and myelinate axons. Here, we will review these recent advances showing the critical roles for RhoGTPases in various aspects of Schwann development and myelination, including the recent discovery of their involvement in Charcot-Marie-Tooth disease. Comparison with potential roles of RhoGTPases in central nervous system myelination will be drawn.