Figure 5.

mcd4–174 Cells secrete/release multiple additional proteins into the media, at least one of which is a known and apparently up-regulated cell wall protein (CWP33). (A) Media proteins. Total labeled media fraction proteins from the experiment described in Figure 3 were resolved by SDS-PAGE. The positions of molecular mass markers are shown to the left. To the right, arrows (←) indicate proteins that appear in both the wild-type (WT) and mcd4–174 media but that are more abundant in the media from mcd4–174 cells, bullets (●) indicate proteins secreted from mcd4–174 cells that are not apparent in the wild-type media lane, and open arrowheads indicate proteins secreted from wild-type but not mcd4–174 cells. The thick arrow denotes the position of an abundant, ∼33-kDa protein shown to be CWP33 (cell wall protein 33). (B) CWP33. Pulse-labeled and chased intracellular (C) and extracellular/media (M) fractions were immunoprecipitated for CWP33 (thick arrow).