Finally, there is also strong evidence to show that peripheral membrane proteins can undergo palmitoylation beyond the confines of the Golgi in yeast cells. As discussed earlier, Ras is modified by ER-localized ERF2 (Bartels et al., 1999) , and palmitoylation and membrane association of the yeast vacuolar fusion protein Vac8 are also markedly reduced after depletion of the DHHC protein Pfa3, which is localized to the vacuole membrane (Hou et al., 2005; Smotrys et al., 2005) . modulated by distinct posttranslational modifications present on the target protein.