Figure 6.

ER-to-Golgi transport of GPI-anchored proteins is defective in mcd4–174. (A) Gas1p transport. Wild-type (WT; GY1446), sec18–1 (SEY5188), and mcd4–174 (GY1450) cells were incubated at 24 or 38°C for 15 min, pulse-labeled with ³⁵S-methionine for 10 min, and chased for 40 min. Gas1p was recovered by immunoprecipitation. Shown to the right are the known molecular masses of ER-modified (∼105 kDa) and Golgi-modified/mature Gas1p (∼125 kDa). (B) Mkc7p transport. Wild-type (WT; GY1446), sec18–1 (SEY5188), and mcd4–174 (GY1450) cells harboring pRS425-MKC7HA were incubated at 24 or 38°C for 15 min, pulse labeled with ³⁵S-methionine for 10 min, and chased for 30 min. Mkc7-HA was recovered by immunoprecipitation with the 12CA5 monoclonal antibody. The positions of molecular mass markers are shown to the right.