New components of Yarrowia lipolytica Golgi multi-protein complexes containing the alpha-1,6-mannosyltransferases YlMnn9p and YlAnl1p.

This paper reports the identification and the characterization of two new components of Yarrowia lipolytica Golgi multi-protein complexes. Blast analysis on the Y. lipolytica complete genome allowed us to find a new alpha-1,6-mannosyltransferase, YlAnl2p, which displays an overall identity of 59% and shares a Golgi cellular localization with the previously described YlAnl1p. Moreover, YlAnl2p was shown to directly interact with YlMnn9p using the two-hybrid system suggesting that the two proteins form a second Golgi sub-complex. In order to further elucidate the composition of the Y. lipolytica Golgi complexes containing alpha-1,6-mannosyltransferases, as M-Pol complexes in Saccharomyces cerevisiae, two-hybrid screens were performed using either YlMnn9p or YlAnl1p as bait. A specific partner of YlAnl1p, named YlAni1p was identified. The two proteins were shown to co-localize and co-precipitate in Y. lipolytica. YlAni1p, which displays a coiled-coil domain as Golgin, and YlAnl1p could be involved in the Golgi apparatus maintenance in the yeast Y. lipolytica.