Switching between nitrogen and glucose limitation: Unraveling transcriptional dynamics in Escherichia coli
| Autor: | Salaheddine Laghrami, Jan Müller, Michael Löffler, Andreas Freund, Karin Schäferhoff, Ralf Takors, Joana Danica Simen, Günter Jäger |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Nitrogen Glucose uptake 030106 microbiology Anti-sigma factors Sigma Factor Bioengineering Acetates Biology Applied Microbiology and Biotechnology 03 medical and health sciences Sigma factor Escherichia coli Transcriptional regulation Metabolome Regulation of gene expression Escherichia coli Proteins DNA-Directed RNA Polymerases Gene Expression Regulation Bacterial General Medicine Glucose 030104 developmental biology Biochemistry Ketoglutaric Acids bacteria rpoN rpoS Biotechnology |
| Zdroj: | Journal of Biotechnology. 258:2-12 |
| ISSN: | 0168-1656 |
| Popis: | Transcriptional control under nitrogen and carbon-limitation conditions have been well analyzed for Escherichia coli. However, the transcriptional dynamics that underlie the shift in regulatory programs from nitrogen to carbon limitation is not well studied. In the present study, cells were cultivated at steady state under nitrogen (ammonia)-limited conditions then shifted to carbon (glucose) limitation to monitor changes in transcriptional dynamics. Nitrogen limitation was found to be dominated by sigma 54 (RpoN) and sigma 38 (RpoS), whereas the "housekeeping" sigma factor 70 (RpoD) and sigma 38 regulate cellular status under glucose limitation. During the transition, nitrogen-mediated control was rapidly redeemed and mRNAs that encode active uptake systems, such as ptsG and manXYZ, were quickly amplified. Next, genes encoding facilitators such as lamB were overexpressed, followed by high affinity uptake systems such as mglABC and non-specific porins such as ompF. These regulatory programs are complex and require well-equilibrated and superior control. At the metabolome level, 2-oxoglutarate is the likely component that links carbon- and nitrogen-mediated regulation by interacting with major regulatory elements. In the case of dual glucose and ammonia limitation, sigma 24 (RpoE) appears to play a key role in orchestrating these complex regulatory networks. |
| Databáze: | OpenAIRE |
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