Abstract |
Glutamine synthetase activity is modulated by nitrogen repression and by two distinct inactivation processes. Addition of glutamine to exponentially grown yeast leads to enzyme inactivation. 50% of glutamine synthetase activity is lost after 30 min (a quarter of the generation time). Removing glutamine from the growth medium results in a rapid recovery of enzyme activity. A regulatory mutation (gdhCR mutation) suppresses this inactivation by glutamine in addition to its derepressing effect on enzymes involved in nitrogen catabolism. The gdhCR mutation also increases the level of proteinase B in exponentially grown yeast. Inactivation of glutamine synthetase is also observed during nitrogen starvation. This inactivation is irreversible and consists very probably of a proteolytic degradation. Indeed, strains bearing proteinase A, B and C mutations are no longer inactivated under nitrogen starvation.
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Authors | C Legrain, S Vissers, E Dubois, M Legrain, J M Wiame |
Journal | European journal of biochemistry
(Eur J Biochem)
Vol. 123
Issue 3
Pg. 611-6
(Apr 1982)
ISSN: 0014-2956 [Print] England |
PMID | 6122575
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Glutamate-Ammonia Ligase
- Nitrogen
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Topics |
- Glutamate-Ammonia Ligase
(antagonists & inhibitors, genetics, physiology)
- Mutation
- Nitrogen
(pharmacology)
- Saccharomyces cerevisiae
(enzymology)
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