Figure 4

The mature form of OSTα is glycosylated when co-transfected with OSTβ, but this is not necessary for plasma membrane localization. COS7 cells were treated with 0.5 μg.ml of tunicamycin or vehicle at the time of transfection and cells were cultured for an additional 48 hrs. (A) Proteins were separated by PAGE, transferred to PVDF membrane, and OST subunits were detected with anti-FLAG and anti-Myc antibodies. The two higher molecular weight bands (arrows) are not detectable after inhibition of glycosylation with tunicamycin. (B) The two higher molecular weight bands (m and p) are sensitive to digestion with PNGase F, but not Endo H, indicating that they contain complex oligosaccharides. m = mature, p = precursor, u = unglycosylated. (C) The lack of glycosylation of OSTα after tunicamycin treatment does not prevent its plasma membrane localization. Anti-FLAG-green, anti-Myc-red