Rho GTPases are molecular switches that regulate many essential cellular processes, including Actin dynamics, cell adhesion, cell-cycle progression and transcription. The Rho-type guanosine triphosphatase (GTPase), CDC42, has been implicated in a variety of functions in the yeast life cycle, including septin organization for cytokinesis, pheromone response, haploid invasive growth and the establishment and maintenance of cell polarity. In yeast, the role of CDC42 in polarization of cell growth includes polarization of the Actin cytoskeleton, which delivers secretory vesicles to growth sites at the plasma membrane.
