TABLE 1.
Effects of mutations in the glnA and gdhA genes on amdS::lacZ expression
| Relevant genotypeb | β-Galactosidase activitya
|
|||
|---|---|---|---|---|
| Glutamine | Nitrogen-free | Ammonium | Glutamate | |
| glnA+gdhA+ | 8.0 (1.7) | 234.0 (21.6) | 11.4 (2.8) | 93.7 (8.7) |
| glnAΔ gdhA+ | 14.7 (3.1) | 170.0 (19.5) | 23.5 (2.2) | 68.7 (7.6) |
| glnA+gdhA10 | 30.0 (3.8) | 219.6 (24.5) | 76.5 (8.8) | 104.4 (18.2) |
| glnAΔ gdhA10 | 33.2 (4.8) | 148.2 (23.4) | 126.0 (24.5) | 110.8 (15.8) |
a
Mycelia were grown overnight on 1% glucose medium containing 10 mM glutamine and transferred to medium containing either 10 mM ammonium, 10 mM glutamate, or no added nitrogen source (nitrogen-free) for 4 h. The assay results presented are the average of six independent experiments, with standard errors in parentheses, and β-galactosidase activities are expressed as units per minute per milligram of soluble protein.
b
All strains contained the areA102 mutation and an amdS::lacZ reporter gene replaced at the amdS locus.