Figure 9.

Intracellular transport of identified glycoproteins in KKAA cells (treated in the presence or absence of tet for 48 h). (A) Transferrin receptor: Cells were pulsed for 10 min with [³⁵S]methionine and chased as indicated. The receptor was immunoprecipitated from the Triton X-100–solubilized cells and digested (or not) with endo H. (B) Cathepsin D: Cells were metabolically labeled for 1 h followed by a chase for 3 or 6 h. The culture medium was precipitated with methanol. Cathepsin D was immunoprecipitated from the resuspended methanol precipitate. (C) α-Glucosidase: Cells were metabolically labeled for 1 h and chased as indicated, and the enzyme was immunoprecipitated after cell solubilization with Triton X-100. The immunoprecipitates were separated by SDS-PAGE and visualized by fluorography.