Figure 6.
Vps52p, Vps53p, and Vps54p are stable only when coexpressed. (A) Steady-state levels of integrated, HA-tagged versions of Vps52p, Vps53p, and Vps54p in mutant strains. Detergent extracts were made from each of the indicated strains (lane 1, LCY226; lane 2, LCY229; lane 3, LCY233; lane 4, LCY251; lane 5, LCY252; lane 6, LCY255; lane 7, LCY270; lane 8, LCY253; lane 9, LCY254), adjusted to give equal protein concentrations as determined by Bradford assay, and analyzed by Western blotting with an anti-HA mAb. Blots were visualized by chemiluminescence and quantified by chemifluorescence (see MATERIALS AND METHODS). The percentage of each HA-tagged protein remaining in the delete strains, normalized to wild-type values, is shown. (B–D) Pulse-chase analysis of protein stability in delete strains. The strains described above were labeled with [35S]methionine for 10 min and chased for the times indicated before immunoprecipitating with HA antibodies. Samples were analyzed by SDS-PAGE and fluorography.