Regulation of glutamine synthetase activity by transcriptional and posttranslational modifications negatively influences ganoderic acid biosynthesis in Ganoderma lucidum
| Autor: | Shuqi Song, Ang Ren, Jing Zhu, Mingwen Zhao, Zehua Sun, Lingdan Lian, Liang Shi |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Gs alpha subunit
Reishi Nitrogen Secondary Metabolism Biology Microbiology Fungal Proteins 03 medical and health sciences chemistry.chemical_compound Biosynthesis Glutamate-Ammonia Ligase Glutamine synthetase Gene Expression Regulation Fungal Post-translational regulation Secondary metabolism Ecology Evolution Behavior and Systematics 030304 developmental biology 0303 health sciences Nitrates Mycelium 030306 microbiology Ganoderic acid Yeast Triterpenes chemistry Biochemistry Protein Processing Post-Translational Intracellular |
| Zdroj: | Environmental microbiologyReferences. 23(2) |
| ISSN: | 1462-2920 |
| Popis: | Glutamine synthetase (GS), a central nitrogen metabolic enzyme, plays important roles in the nitrogen regulation network and secondary metabolism in fungi. However, the mechanisms by which external nitrogen sources regulate fungal GS activity have not been determined. Here, we found that GS activity was inhibited under nitrate conditions in Ganoderma lucidum. By constructing gs-silenced strains and adding 1 mM GS inhibitor to inhibit GS activity, we found that a decrease in GS activity led to a decrease in ganoderic acid biosynthesis. The transcription of gs increased approximately 5-fold under nitrate conditions compared with that under ammonia. Electrophoretic mobility shift and yeast one-hybrid assay assays showed that gs was transcriptionally regulated by AreA. Although both gs expression and GS protein content increased under nitrate conditions, the GS activity still decreased. Treatment of recombinant GS with SIN-1 (protein nitration donor) resulted in a strengthened nitration accompanied by a 71% decrease in recombinant GS activity. Furthermore, intracellular GS could be nitrated from mycelia cultivated under nitrate conditions. These results indicated that GS activity could be inhibited by NO-mediated protein nitration. Our findings provide the first insight into the role of transcriptional and posttranslational regulation of GS activity in regulating secondary metabolism in fungi. This article is protected by copyright. All rights reserved. |
| Databáze: | OpenAIRE |
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