Combinatorial stress responses: direct coupling of two major stress responses in Escherichia coli

Authors:

Daniel R. Brown, Geraint Barton, Zhensheng Pan, Martin Buck and Sivaramesh Wigneshweraraj

doi: 10.15698/mic2014.09.168
Volume 1, pp. 315 to 317, published 01/09/2014.

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Affiliations:

1 MRC Centre for Molecular Bacteriology and Infection, Imperial College London, SW7 2AZ, UK.

2 Centre for Systems Biology and Bioinformatics, Division of Biosciences, Imperial College London, SW7 2AZ, UK.

3 Department of Life Sciences, Imperial College London, SW7 2AZ, UK.

Keywords: 

stringent response, NtrC, transcription, sigma 54, RNA polymerase, (p)ppGpp.

Corresponding Author(s):

Daniel R. Brown, MRC Centre for Molecular Bacteriology and Infection, 4.40 Flowers Building, Imperial College London, South Kensington Campus; London SW7 2AZ, UK d.brown06@imperial.ac.uk

Conflict of interest statement:

None.

Please cite this article as:

Daniel R. Brown, Geraint Barton, Zhensheng Pan, Martin Buck and Sivaramesh Wigneshweraraj (2014). Combinatorial stress responses: direct coupling of two major stress responses in Escherichia coli. Microbial Cell 1(9): 315-317.

© 2014 Brown et al. This is an open-access article released under the terms of the Creative Commons Attribution (CC BY) license, which allows the unrestricted use, distribution, and reproduction in any medium, provided the original author and source are acknowledged.

Abstract:

Nitrogen is an essential element for all life, and this is no different for the bacterial cell. Numerous cellular macromolecules contain nitrogen, including proteins, nucleic acids and cell wall components. In Escherichia coli and related bacteria, the nitrogen stress (Ntr) response allows cells to rapidly sense and adapt to nitrogen limitation by scavenging for alternative nitrogen sources through the transcriptional activation of transport systems and catabolic and biosynthetic operons by the global transcriptional regulator NtrC. Nitrogen-starved bacterial cells also synthesize the (p)ppGpp effector molecules of a second global bacterial stress response – the stringent response. Recently, we showed that the transcription of relA, the gene which encodes the major (p)ppGpp synthetase in E. coli, is activated by NtrC during nitrogen starvation. Our results revealed that in E. coli and related bacteria, NtrC functions in combinatorial stress and serves to couple two major stress responses, the Ntr response and stringent response.