Localization and targeting of the Saccharomyces cerevisiae Kre2p/Mnt1p alpha 1,2-mannosyltransferase to a medial-Golgi compartment

Both the function of Kre2p as a txl,2-mannosyltransferase and its slow receipt of MNNl-dependent modifications imply localization to a Golgi compartment. Kre2p subcellular localization was examined by indirect immunofluorescence and showed a punctate pattern of fluorescent signals indicative of a Golgi association (Fig. 4 C) . Between 3 and 14 structures per cell can be seen, depending on individual cells and the plane of focus. Punctiform fluorescence was never seen with the anti-Kre2p antibody in kre2:: TRP1 cells (Fig. 4 A) . The Kre2p signal distribution did not overlap with nuclei or mitochondria viewed by D N A staining with DAPI ( Fig. 4 D) .