Al., 2012), indicating a conserved interaction ability of the KXD/E motif and COPI coatomer from different organisms. The COPI-binding ability of the KXD/E motif in yeast prompted us to examine further whether this COPI-interacting motif has a similar Golgi retention effect in other yeast membrane proteins. We next used a gain-of-function approach by adding the KXD/E motif to the C-terminus of vac