Membrane association and targeting of prenylated Ras-like GTPases.

The regulatory function of the Ras-like GTPases in diverse cellular processes, such as growth, cell movement, and protein trafficking, is critically dependent on targeting to the proper cellular membrane. Prenylation of Ras, Rho/Rac, and Rab GTPases, defined as the covalent addition of isoprenyl groups to cysteine residues near or at their carboxyl terminus, is the first and necessary step that leads to membrane binding and targeting of these proteins. Recent progress on the molecular mechanisms of prenylation, membrane association, and targeting of Ras, Rho/Rac, and Rab proteins will be reviewed here. The detailed understanding of these targeting mechanisms may allow future development of specific therapeutic agents that interfere with the function of each one of these proteins.