TABLE 3.
Cell-based zinc toxicity in DT40 cells stably transfected with various site-directed ZnT2 TNZD mutants
The viability of cells exposed to the indicated concentrations of ZnSO4 for 72 h was determined by determining the number of viable cells using Trypan blue exclusion. The results of single transfectant cells (G87R, G280R, T312M, or E355Q) were recently published (7). Relative values presented are evaluations of the average values of three independent experiments.
| Expressed ZnT2 | ZnSO4 (μm) |
|||||
|---|---|---|---|---|---|---|
| 50 | 60 | 70 | 80 | 90 | 100 | |
| DT40 ZnT1−/−MT−/−ZnT4−/− cells | ||||||
| Untransfected | +++a | − | − | − | − | − |
| WT-HA | +++ | +++ | +++ | +++ | +++ | ++ |
| G87R-HA | +++ | − | − | − | − | − |
| G280R-HA | +++ | − | − | − | − | − |
| T312M-HA | +++ | − | − | − | − | − |
| E355Q-HA | +++ | − | − | − | − | − |
| DT40 ZnT1−/−MT−/−ZnT4−/− cells | ||||||
| WT-HA + WT-FLAG | +++ | +++ | +++ | +++ | +++ | ++ |
| WT-FLAG + G87R-HA | +++ | +++ | ++ | + | − | − |
| WT-HA + G280R-FLAG | +++ | +++ | +++ | +++ | ++ | + |
| WT-HA + T312M-FLAG | +++ | +++ | +++ | +++ | ++ | + |
| WT-HA + E355Q-FLAG | +++ | +++ | +++ | +++ | +++ | ++ |
a The symbols represent: +++: growing to confluence; ++, +: decreased growth (20–50% or up to 20% relative to +++); −, no growth.