Assessment of the protein stability of NHE6 variants. AP-1 cells were transiently transfected with NHE6HA WT of CS-linked variants for 24 h and then treated with 150 μg/ml cycloheximide (CHX) for the indicated time points and lysed, and equal amounts of protein (20 μg) were analyzed by Western blotting using a mouse monoclonal anti-HA antibody. Blots were reprobed with a mouse monoclonal anti-GAPDH antibody to control for loading. Blots are representative images from four separate experiments. fg, fully-glycosylated; cg, core-glycosylated; d, dimeric; m, monomeric.