Figure 2.

Rho GTPases. (A) Phylogenetic tree based on alignment of the aminoacid sequences of the 20 Rho GTPases. Rnd proteins form a distinct branch, which is closely related to Rho members. (B) Classical Rho GTPases cycle between an inactive GDP-bound state and an active GTP-bound state. In their active conformation they transduce the signal to intracellular effectors. Two classes of molecules promote the regulatory cycle: GEFs stimulate the exchange of GDP with GTP, whereas GAPs stimulates the GTP hydrolysis.