Table 3. Mutational loss of NaVBP and MotPS affect pH homeostasis in alkaline-shifted cells.
| Cytoplasmic pH (pHin) and Δψ 10 min after a pH 8.5 → 10.5 shift
|
||||
|---|---|---|---|---|
| 100 mM added Na+
|
2.5 mM added Na+
|
|||
| Strain | pHin | Δψ, mV | pHin | Δψ, mV |
| Wild type | 8.46* | -173 | 9.03 | -161 |
| SC34 (ΔncbA) | 8.66 | -178 | 9.43 | -159 |
| SC34-R (ΔncbA, ncbA restored) | 8.48 | -170 | 9.02 | -158 |
| Mot6 (ΔmotPS) | 8.52 | -169 | 9.03 | -155 |
| SC34/Mot6 (ΔncbA, ΔmotPS) | 8.72 | -177 | 9.51 | -138 |
*
The values are mean values from at least two independent experiments in which cells equilibrated at pH 8.5 were subjected to shift of pHo to 10.5. The standard deviations of the mean for pHin were ≤2% and for Δψ were ≤5%.