Table 2. Intracellular levels of amino acids in normal BTN1+ (B-11718) and btn1-Δ (B-13048) cells indicate that levels of arginine and lysine are significantly decreased in the vacuoles of btn1-Δ strains.
| Intracellular free amino acid content, nmol per 108 cells
|
||||
|---|---|---|---|---|
|
BTN1+
|
btn1-Δ
|
|||
| Amino acid | Vacuole | Cytosol | Vacuole | Cytosol |
| Ala | 31 ± 5 | 4 ± 1 | 24 ± 3 | 5 ± 1 |
| Asn | — | — | — | — |
| Asp | 4 ± 1 | >1 | 4 ± 1 | — |
| Arg | 117 ± 14 | 5 ± 1 | 18 ± 5 | — |
| Cys | — | — | — | — |
| Gly | 25 ± 5 | 3 ± 1 | 20 ± 4 | 3 ± 1 |
| Gln | 2 ± 1 | — | 3 ± 1 | — |
| Glu | 42 ± 4 | — | 16 ± 4 | — |
| His | — | — | — | — |
| Ile | 5 ± 1 | 1 ± 1 | 3 ± 1 | 1 ± 1 |
| Leu | 4 ± 1 | — | 3 ± 1 | >1 |
| Lys | 103 ± 8 | 12 ± 4 | 11 ± 3 | 2 ± 1 |
| Met | 3 ± 1 | 10 ± 2 | 2 ± 1 | 11 ± 3 |
| Phe | 2 ± 1 | — | 2 ± 1 | — |
| Pro | 8 ± 2 | 2 ± 2 | 6 ± 2 | 3 ± 1 |
| Ser | 15 ± 3 | 7 ± 3 | 15 ± 3 | 7 ± 3 |
| Thr | — | 5 ± 1 | — | 6 ± 2 |
| Trp | — | — | — | — |
| Tyr | 2 ± 1 | — | — | — |
| Val | 12 ± 2 | 2 ± 1 | 10 ± 2 | 2 ± 1 |
Results are presented as mean ± SD of four independently derived samples. Differences in vacuolar arginine and lysine levels in BTN1+ and btn1-Δ are statistically significant with P < 0.05 as determined by standard t test.