α-Gal A and Tat mRNA expression and α-gal A enzyme activity. (A) Similar levels of α-gal A and Tat mRNA expression in transduced 3T3 cells were confirmed by RT-PCR. (B) α-Gal A activity secreted from transduced HeLa cells. (C) Uptake of secreted α-gal A and α-gal A/Tat in Fabry mouse fibroblasts with or without M6P. NT, non-transduced; RT, reverse transcriptase; sup, supernatant; M6P, mannose-6-phosphate. α-Gal A activity assays were measured in triplicates. Values are mean ± SD.