Table IV. Overexpression of VAC14 does not enable fab1-2 to produce elevated levels of PtdIns(3,5)P2 after exposure to osmotic stress.
| PtdIns(3)P | PtdIns(3,5)P2 | |||
|---|---|---|---|---|
| 0.9 M NaCl | + | − | + | − |
| fab1-2 with pRS426, 423, and 424 | 165 ± 1 | 150 ± 10 | 12 ± 2 | 3.1 ± 0.3 |
| fab1-2 with FAB1 2μ | 85 ± 1 | 89 ± 5 | 27 ± 1 | 3.1 ± 0.9 |
| fab1-2 with VAC14 2μ | 144 ± 9 | 122 ± 9 | 8 ± 2 | 2.4 ± 0.5 |
| fab1-2 with VAC14 and FAB1 2μ | 97 ± 1 | 100 ± 4 | 40 ± 4 | 2.8 ± 0.2 |
Cells were grown in inositol-free media in the presence of 0.01 mCi/ml 3H inositol. 0.9 M NaCl was added to half the cultures for 10 min prior to extraction. Cellular lipids were extracted and analyzed as described in Materials and methods. The cpm in each peak was corrected for the total number of cells analyzed by expressing each as a percentage of total cpm eluted. Then these values were normalized to PtdIns(3)P with no salt added in fab1-2 with VAC14 and FAB1 2μ (which was 2.1% of total cpm eluted; 84,000 cpm of 4 × 106 total cpm). The data (mean ± standard deviation) were calculated from results obtained in three independent experiments.