Ykt6p functions in at least two different SNARE complexes in four membrane traffic pathways in yeast. Ykt6p forms a SNARE complex with Sed5p, Sft1p, and Vti1p (or Gos1p) in retrograde transport to the cis-Golgi compartment. Ykt6p also functions in SNARE complex formation with Vam3p, Vam7p, and Vti1p in the CPY, ALP and API transport pathways to the vacuole. Ykt6p may also function in vesicle fusion with the PVC (Dilcher et al., 2001).