(A) Myc-tagged wild-type, p.Met165Thr-mutated, and p.Pro253Leu-mutated POMGNT2 cDNAs were transfected into HeLa cells. Both the myc-tagged wild-type and missense mutants of POMGNT2 (c-myc, red) were costained with endoplasmic reticulum (ER) protein, protein disulfide isomerase (PDI, green). Blue indicates the transfected cells with the marker protein, ZsGreen. The bar represents 20 μm. (B) Expression levels of myc-tagged wild-type (wild), Met165Thr-mutated (M165T), and Pro253Leu-mutated (P253L) POMGNT2 in HEK293 cells (arrow). (C) Specific POMGNT activity of wild-type and mutated POMGNT2 expressed in HEK293 cells. The relative POMGNT activity was calculated against that of wild-type POMGNT2. Data obtained from 5 individual measurements are shown as the mean, where the error bars indicate the SD. **p < 0.01 vs wild type according to the Mann-Whitney U test.