Rac GTPases play multiple roles in erythropoiesis

Abstract

The four members of the Rac family of GTPases –Rac1, Rac2, Rac3 and RhoG – are members of the Rho superfamily that regulates the organization, dynamics, and function of the actin cytoskeleton. Rac GTPases play significant roles in many cellular processes including migration, cytokinesis, lamellipodia formation, and cell polarity.1 Genetically modified mice deficient in each of the Racs are available;2–6 deficiency of Rac1 causes intrauterine death, whereas mice defective in Rac2, Rac3 or RhoG develop fairly normally. Rac proteins may have redundant functions in certain types of cells and unique functions in others.