| Modification Notes |
In Saccharomyces cerevisiae, the small GTPase Rho1 plays an essential role in the control of cell wall synthesis and organization of the actin cytoskeleton (1). In the budding yeast S. cerevisiae, one of the main structural components of the cell wall is 1,3-beta-glucan produced by 1,3-beta-glucan synthase (GS) (2). Rho1 is required for 1,3-beta-glucan synthase activity, as yeast GS is composed of a putative catalytic subunit encoded by FKS1 and FKS2 and a regulatory subunit encoded by RHO1 (2,3). Rho1 is also required for activation of protein kinase C and the cell integrity pathway, as well as for progression into G1, cell polarization and exocytosis (3). Activation of PKC1 occurs via the GTPase RHO1 and the kinase pair PKH1 and PKH2 (4). Several regulators for Rho1 are known, including the GTPase-activating proteins (GAPs) SAC7, BEM2 and BAG7 (1). Rho1 directs formin-mediated actin ring assembly during budding yeast cytokinesis (5). |