| Autor: |
Guerrero, Carlos A., Aranda, Cristina, DeLuna, Alexander, Filetici, Patrizia, Riego, Lina, Anaya, Víctor, González, Alicia |
| Předmět: |
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| Zdroj: |
Current Genetics; Mar2005, Vol. 47 Issue 3, p163-171, 9p |
| Abstrakt: |
Debaryomyces hanseniiis adapted to grow in saline environments, accumulating high intracellular Na+ concentrations. Determination of theDhGDH1-encoded NADP-glutamate dehydrogenase enzymatic activity showed that it increased in a saline environment. Thus, it was proposed that, in order to overcome Na+ inhibition of enzyme activity, this organism possessed salt-dependent mechanisms which resulted in increased activity of enzymes pertaining to the central metabolic pathways. However, the nature of the mechanisms involved in augmented enzyme activity were not analyzed. To address this matter, we studied the expression ofDhGDH1andDhGLN1encoding glutamine synthetase, which constitute the central metabolic circuit involved in ammonium assimilation. It was found that: (1) expression ofDhGDH1is increased whenD. hanseniiis grown in the presence of high NaCl concentrations, while that ofDhGLN1is reduced, (2)DhGDH1expression inSaccharomyces cerevisiaetakes place in aGLN3- andHAP2,3-dependent manner and (3) salt-dependentDhGDH1andDhGLN1expression involves mechanisms which are limited toD. hanseniiand are not present inS. cerevisiae. Thus, salt-dependent regulation of the genes involved in central metabolic pathways could form part of a strategy leading to the ability to grow under hypersaline conditions. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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