Fig 2. The effects of tunicamycin, an N-linked glycosylation inhibitor, on lowering the protein levels of ABCC11.

Forty-eight hours after the transfection, MDCKII cells transiently expressing ABCC11 wild-type (WT) were cultured with tunicamycin (TNM) (0, 0.8, and 4.0 μg/mL) for further 24 h, then cell lysate samples were prepared after the treatment without (A) or with (B) PNGase F, and then subjected to immunoblotting. α-Tubulin: a loading control. P: PNGase F-treated ABCC11 WT as a control for the band position of non-glycosylated ABCC11 (details are described in Materials and Methods). The signal intensity ratio (ABCC11/α-tubulin) of the immunoreactive bands was determined and normalized to that in TNM-untreated cells (0 μg/mL in B). Data are expressed as mean ± S.D. n = 5. Statistical analyses for significant differences were performed according to Student’s t test (**, P < 0.01 vs control).