Supplementary Figure 1.

Characterization of IR and IGF1R expression in HepG2 and Hep3B cells.

(A) Flow cytometry conducted on both cell lines using mAb 23-14 (IGF1R; left histogram) or mAb 83-7 (IR; right histogram) shows that both cell lines express very similar surface amounts of each receptor.

(B) Cells were treated for 24 hours with vehicle, swainsonine (swain), or kifunensine (kifun) in order to study the glycosylation pattern present on each receptor. Both the IR and IGF1R in Hep3B showed only a partially glycosylated phenotype, while both receptors in HepG2 were much more glycosylated as indicated by the greater decrease in molecular size after swainsonine and kifunensine treatment.