TABLE 3.
Intracellular ATP concentration upon glucose depletion and when glucose is added back to glucose-depleted cellsa
| Condition | ATP level (nmol/mg of protein)
|
||
|---|---|---|---|
| 1 min | 5 min | 20 min | |
| In YEPD | 7.3 ± 0.8 | ND | 8.5 ± 1.0 |
| After YEP treatment | 3.6 ± 0.6 | 4.6 ± 0.5 | 6.1 ± 0.5 |
| After glucose readdition | 4.0 ± 0.5 | 5.4 ± 0.6 | 6.1 ± 0.9 |
Wild-type yeast cells were converted to spheroplasts as described in Materials and Methods. After 15 min at 30°C, spheroplasts were pelleted, resuspended in YEPD or YEP medium at a final density of 3.3 OD/ml, and immediately incubated at 30°C. Samples were removed at 1 min, 5 min, and 20 min. To measure the intracellular ATP concentration after glucose readdition, YEP incubation was followed by an additional incubation with 2% glucose for 1, 5, and 20 min. ATP levels were determined in duplicate, using a luciferin-luciferase system as described in Materials and Methods. The average values ± standard errors from five independent experiments are shown. ND, not done.