Figure 6.

Reduced SGLT2 A89T membrane expression and transport activity. (A) Plasma membrane expression of human SGLT2 wild-type and SGLT2 A89T mutant constructs expressed in HEK293 cells was assessed by immunoblotting of plasma membrane proteins labeled by sulfo-NHS-LC-biotin and isolated with streptavidin agarose beads. Avidin–horseradish peroxidase was used as loading control for surface proteins. The absence of an actin signal confirms the purity of the membrane fraction. (B) Uptake of 50 µM [¹⁴C]-α-MDG by HEK293 cells transfected by the indicated constructs. Data are means±SD. (C) Deglycosylation experiment: 20 µg of total protein isolated from HEK cells transfected by the indicated constructs were treated (right panel) or not (left panel) by PNGase F. Actin was used as a loading control.