The effects of palmitoylation-depalmitoylation dynamics have been extensively analyzed for palmitoylated Ras isoforms (Goodwin et al., 2005; Rocks et al., 2005; Roy et al., 2005) . Farnesylated H-and N-Ras exhibit a weak membrane affinity that mediates interaction with Golgi membranes. Palmitoylation of Ras at this compartment promotes stable membrane association and trafficking from the Golgi to the plasma membrane. Subsequent depalmitoylation releases Ras from the plasma membrane into the cytosol, and the process of palmitoylation at the Golgi and trafficking to the plasma membrane is repeated ( Fig. 1 B) . This palmitoylation cycle achieves a constant flux of Ras proteins from Golgi to plasma membrane and was suggested to prevent spillover of Ras onto other cellular membranes by constantly resetting the intracellular localization (Goodwin et al., 2005; Rocks et al., 2005) .