Figure 5.

Only coexpression of UPIII with UPIb results in an Endo-H–resistant form of UPIII. UPIII was coexpressed with UPIa (lanes 5–8) or UPIb (lanes 9–12). Total cell lysates were treated with Endo-H (lanes 6 and 10) or N-glycanase (N-glycan*) (lanes 8 and 12). As control, samples were incubated under the same condition omitting Endo-H (lanes 5 and 9) or N-glycanase (lanes 7 and 11). All samples were then subjected to SDS-PAGE and Western blotting was carried out using an antibody directed against UPIII. AUM was subjected to the same treatment (lanes 1–4).