Deciphering the response of Mycobacterium smegmatis to nitrogen stress using bipartite active modules.

Kerstin J Williams, William A Bryant, Victoria A Jenkins, Geraint R Barton, Adam A Witney, John W Pinney, Brian D Robertson
Author Information
  1. Kerstin J Williams: Department of Medicine, MRC Centre for Molecular Bacteriology and Infection, South Kensington, London SW7 2AZ, UK.

Abstract

BACKGROUND: The ability to adapt to environments with fluctuating nutrient availability is vital for bacterial survival. Although essential for growth, few nitrogen metabolism genes have been identified or fully characterised in mycobacteria and nitrogen stress survival mechanisms are unknown.
RESULTS: A global transcriptional analysis of the mycobacterial response to nitrogen stress, showed a significant change in the differential expression of 16% of the Mycobacterium smegmatis genome. Gene expression changes were mapped onto the metabolic network using Active Modules for Bipartite Networks (AMBIENT) to identify metabolic pathways showing coordinated transcriptional responses to the stress. AMBIENT revealed several key features of the metabolic response not identified by KEGG enrichment alone. Down regulated reactions were associated with the general reduction in cellular metabolism as a consequence of reduced growth rate. Up-regulated modules highlighted metabolic changes in nitrogen assimilation and scavenging, as well as reactions involved in hydrogen peroxide metabolism, carbon scavenging and energy generation.
CONCLUSIONS: Application of an Active Modules algorithm to transcriptomic data identified key metabolic reactions and pathways altered in response to nitrogen stress, which are central to survival under nitrogen limiting environments.

References

Mol Microbiol. 2008 Feb;67(4):861-80 [PMID: 18179599]
Mol Microbiol. 2002 Feb;43(3):717-31 [PMID: 11929527]
PLoS One. 2010 Jan 07;5(1):e8614 [PMID: 20062806]
Mol Microbiol. 2002 Oct;46(2):319-30 [PMID: 12406211]
Tuberculosis (Edinb). 2004;84(3-4):218-27 [PMID: 15207491]
J Antimicrob Chemother. 2011 Jul;66(7):1489-98 [PMID: 21613307]
PLoS Comput Biol. 2009 Aug;5(8):e1000489 [PMID: 19714220]
Tuberculosis (Edinb). 2004;84(3-4):205-17 [PMID: 15207490]
J Mol Microbiol Biotechnol. 2009;17(1):20-9 [PMID: 18824837]
Nat Biotechnol. 2010 Sep;28(9):977-82 [PMID: 20802497]
IUBMB Life. 2008 Oct;60(10):643-50 [PMID: 18493948]
Proc Natl Acad Sci U S A. 2003 Aug 5;100(16):9440-5 [PMID: 12883005]
BMC Genomics. 2011 Apr 04;12:175 [PMID: 21463507]
J Gen Microbiol. 1979 Dec;115(2):259-71 [PMID: 393800]
Nucleic Acids Res. 2005 Oct 07;33(17):5691-702 [PMID: 16214803]
Tuberculosis (Edinb). 2004;84(3-4):228-38 [PMID: 15207492]
Microbiol Rev. 1995 Dec;59(4):604-22 [PMID: 8531888]
J Biol Chem. 1952 May;197(2):717-32 [PMID: 12981104]
Annu Rev Microbiol. 2007;61:349-77 [PMID: 17506680]
J Microbiol Biotechnol. 2007 Feb;17(2):187-94 [PMID: 18051748]
Nucleic Acids Res. 2012 Jan;40(Database issue):D109-14 [PMID: 22080510]
FEMS Microbiol Lett. 2012 May;330(1):38-45 [PMID: 22356601]
J Mol Microbiol Biotechnol. 2007;12(1-2):139-46 [PMID: 17183221]
BMC Genomics. 2013 May 04;14:301 [PMID: 23642041]
Appl Microbiol Biotechnol. 2011 Feb;89(4):1149-59 [PMID: 21229241]
BMC Syst Biol. 2013 Mar 25;7:26 [PMID: 23531303]
FEMS Microbiol Rev. 2010 Jul;34(4):588-605 [PMID: 20337720]
Proc Natl Acad Sci U S A. 2005 Oct 25;102(43):15545-50 [PMID: 16199517]
J Bacteriol. 2007 Jun;189(11):3969-76 [PMID: 17384194]
Proc Natl Acad Sci U S A. 2000 Dec 19;97(26):14674-9 [PMID: 11121068]
J Bacteriol. 2008 Nov;190(21):7108-16 [PMID: 18689485]
Bioinformatics. 2002;18 Suppl 1:S233-40 [PMID: 12169552]
J Mol Microbiol Biotechnol. 2007;12(1-2):131-8 [PMID: 17183220]
Stat Appl Genet Mol Biol. 2004;3:Article3 [PMID: 16646809]
Annu Rev Microbiol. 2003;57:155-76 [PMID: 12730324]
PLoS Comput Biol. 2011 Jun;7(6):e1002060 [PMID: 21738454]

Grants

  1. MR/J006874/1/Medical Research Council
  2. BB/G020434/1/Biotechnology and Biological Sciences Research Council

MeSH Term

Algorithms
Gene Expression Profiling
Genome, Bacterial
Genomics
Hydrogen Peroxide
Mycobacterium smegmatis
Nitrogen
Stress, Physiological

Chemicals

Hydrogen Peroxide
Nitrogen

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