Advertisement

Quorum Sensing pp 159-171 | Cite as

Defining the Structure and Function of Acyl-Homoserine Lactone Autoinducers

  • Mair E. A. ChurchillEmail author
  • Hiruy M. Sibhatu
  • Charis L. Uhlson
Protocol
Part of the Methods in Molecular Biology book series (MIMB, volume 692)

Abstract

Quorum sensing plays a central role in regulating many community-derived symbiotic and pathogenic relationships of bacteria, and as such has attracted much attention in recent years. Acyl-homoserine lactones (AHLs) are important signaling molecules in the quorum sensing gene-regulatory processes found in numerous gram-negative species of bacteria that interact with eukaryotic organisms. AHLs are produced by acyl-homoserine lactone synthases. Bacteria can have multiple genes for AHL synthase enzymes, and such species are likely to produce several different types of AHLs. Determination of the types and the relative amounts of AHLs produced by AHL synthases in bacteria under varied conditions provides important insights into the mechanism of AHL synthase function and the regulation of transcriptional cascades initiated by quorum sensing signaling. This chapter describes a mass spectrometry method for determining the types and relative amounts of AHLs present in a sample.

Key words

Acyl-homoserine lactone AHL Quorum sensing Mass spectrometry AHL synthase 

Notes

Acknowledgments

The authors would like to thank Drs. Ty Gould and Robert C. Murphy for their contributions in initially developing this method, Dr. Jake Herman for help in refining the method, and Dr. Joseph Hankin, Chris Johnson, and Wesley Martin for their assistance with the mass spectrometry. We also thank Dr. Robert C. Murphy for helpful suggestions and for use of the mass spectrometry equipment, which is supported by the Lipid Maps Large Scale Collaborative Grant (NIH GM069338 to R.C.M.). This work was supported by Grants from the National Science Foundation #0703467 and #0821220.

References

  1. 1.
    Fuqua, C. and Eberhard, A. (1999) Signal generation in autoinduction systems: synthesis of acylated homoserine lactones by LuxI-type proteins, In G. Dunny and S.C. Winans (eds.), Cell–cell signaling in bacteria. ASM Press, Washington, DC. 211–230.Google Scholar
  2. 2.
    Pearson, J.P., Passador, L., Iglewski, B.H., and Greenberg, E.P. (1995). A second N-acylhomoserine lactone signal produced by Pseudomonas aeruginosa. Proc Natl Acad Sci USA 92, 1490–1494.PubMedCrossRefGoogle Scholar
  3. 3.
    Churchill, M.E.A. and Herman, J.P. (2008) Acyl-homoserinelactone biosynthesis: structure and mechanism. Chapter 17, In Stephen Winans and Bonnie Bassler (eds.), Chemical communication among bacteria. ASM Press, Washington, DC.Google Scholar
  4. 4.
    Shaw, P.D., Ping, G., Daly, S.L., Cha, C., Cronan, J.E., Rinehart, K.L., and Farrand, S.K. (1997) Detecting and characterizing N-acyl-homoserine lactone signal molecules by thin-layer chromatography. Proc Natl Acad Sci USA 94, 6036–6041.PubMedCrossRefGoogle Scholar
  5. 5.
    Gould, T.A., Herman, J.P., Krank, J., Murphy, R.C., and Churchill, M.E.A. (2006) Specificity of acyl-homoserine lactone syntheses examined by mass spectrometry. J Bacteriol 188, 773–783.PubMedCrossRefGoogle Scholar
  6. 6.
    Watson, W.T., Minogue, T.D., Val, D.L., Beck von Bodman, S., and Churchill, M.E.A. (2002) Structural basis and specificity of acyl-homoserine lactone signal production in bacterial quorum sensing. Mol Cell 9, 685–694.PubMedCrossRefGoogle Scholar
  7. 7.
    Khan, S.R., Herman, J.P., Krank, K., Serkova, N.J., Churchill, M.E.A., Suga, H., and Farrand, S.K. (2007) N-(3-hydroxy-hexanoyl)-l-homoserine lactone is the biologically relevant quormone that regulates the phz operon of Pseudomonas chlororaphis (aureofaciens) Strain 30-84. Appl Environ Microbiol 73, 7443–55.PubMedCrossRefGoogle Scholar
  8. 8.
    Duerkop, B.A., Herman, J.P., Ulrich, R.L., Churchill, M.E.A., and Greenberg, E.P. (2008) The Burkholderia mallei BmaR3-BmaI3 quorum-sensing system produces and responds to N-3-hydroxy-octanoyl homoserine lactone. J Bacteriol 190, 5137–5141.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Mair E. A. Churchill
    • 1
    Email author
  • Hiruy M. Sibhatu
    • 1
  • Charis L. Uhlson
    • 1
  1. 1.Department of PharmacologyUniversity of Colorado Denver School of MedicineAuroraUSA

Personalised recommendations