Fig. 2.

OS9 is crucial for dislocation of the terminally misfolded glycoprotein, RI₃₃₂. (A) HeLa cells were transduced with either empty vector (pLHCX), wild-type OS9, OS9 R188A, OS9 E212D, or GFP-OS9, using the same virus preparation as in Fig. S4. The five cell lines were then transfected with a construct that specifies truncated ribophorin, RI₃₃₂, pulse-labeled 36 h after transfection for 20 min with ³⁵S, chased for indicated time points, and then lysed in 1% SDS and immunoprecipitated with antibody raised against the luminal portion of ribophorin. The eluates were separated on 10% SDS/PAGE and visualized by autoradiography. # indicates a faster migrating version of RI₃₃₂. (B) Quantitation of the amount of RI₃₃₂ remaining at the indicated time points.