Vesicle membrane protein and R class v-SNARE; contains SNAP receptor and acyltransferase activities; subunit of multiple SNARE complexes involved in trafficking to and within the Golgi, endocytic trafficking to the vacuole, and autophagosome-vacuolar fusion; C-terminal farnesylation and geranylgeranylation are essential for membrane localization and for function in cell wall integrity and autophagy; targeted to the vacuole via the AP-3 pathway; human homolog YKT6 complements a yeast ykt6 mutant