FIGURE 5.

Polyamine uptake by COS7 cells co-transfected with antizymes and AZIN2. A, cells were transfected with equimolecular amounts of each of the mutated antizymes (MAZ1, MAZ2 and MAZ3) and of the empty vector or AZIN2. Control cells were transfected with the empty vector. Polyamine uptake assays were carried out using 2 μm ¹⁴C-labeled putrescine, spermidine or spermine. B, polyamine uptake plots using corrected data subtracting polyamine uptake corresponding to nontransfected cells considering transfection efficiency, that was estimated by fluorescence microscopy of GFP protein overexpressed under the same transfection conditions. Data are shown as mean ± S.E. of triplicate determinations. C, control.