AHL

Full name: [N-]acyl-homoserine lactones

These are small signalling molecules which are employed in "quorum sensing" systems. They are also known as autoinducers (AIs) and are present in many Gram-negative bacteria.

"Although the target genes regulated by AIs are extremely varied, the basic mechanism of AIs biosynthesis and gene regulation seems to be conserved in different bacteria. The general feature of gene regulation by AIs is cell-density dependence, also known as "quorum sensing".

At low cell densities, the AIs are at low concentrations, and, at high cell densities, the AIs can accumulate to a concentration sufficient for activation of related regulatory genes. Because the concentration of AHL's is a key factor in determining virulence gene expression in several pathogenic bacteria, it is possible to develop a strategy for disease control by controlling production of AIs or eliminating AIs produced by pathogenic bacteria."Dong

Acyl-HSL's in different species

"In recent years, AIs have been identified in several Gram-negative bacteria. AIs are involved in the regulation of a range of biological functions, including Ti plasmid conjugal transfer in Agrobacterium tumefaciens, induction of virulence genes in Erwinia carotovora, Erwinia chrysanthemi, Erwinia stewartii, Pseudomonas aeruginosa, Pseudomonas solanacearum, and Xenorhabdus nematophilus, regulation of antibiotic production in Pseudomonas aureofaciens and E. carotovora, regulation of swarming motility in Serratia liquefaciens, and biofilm formation in Pseudomonas fluorescens and P. aeruginosa. Many more bacterial species are known to produce AIs, but the relevant biological functions have not yet been established."Dong

Full Name Molecule abbreviation Species Notes Source Images (from Sigma Aldrich)
Butanoyl-homoserine lactone C4HSL Pseudomonas aeruginosa Sigma Aldrich (#09945) Butryl-homoserine lactone.GIF
N-(3-oxododecanoyl) homoserine lactone (Reference) 3OC12HSL Pseudomonas aeruginosa Las system signaling molecule Part:BBa_C0078 Cayman Chemicals (#10007895) 3OC12HSL.jpg
3-oxohexanoyl-homoserine lactone 3OC6HSL V. fischeri Lux system signaling molecule Sigma Aldrich (#K3007) 3-oxohexanoyl-homoserine lactone.GIF
Hexanoyl-homoserine lactone C6HSL C. violaceum Very similar to 3OC6HSL Sigma Aldrich (#09926) Hexanoyl-homoserine lactone.GIF
Heptanoyl-homoserine lactone C7HSL E. psidii R. IBSBF 435T Sigma Aldrich (#10939) Heptanoyl-homoserine lactone.GIF
Octanoyl-homoserine lactone C8HSL B. cepacia, V. fischeri Sigma Aldrich (#10940) Octanoyl-homoserine lactone.GIF
3-oxoctanoyl-homoserine lactone 3OC8HSL A. tumefaciens Sigma Aldrich (#O1764) 3-Oxooctanoyl-L-homoserine lactone2.GIF
Decanoyl-homoserine lactone C10HSL B. pseudomallei Sigma Aldrich (#17248) Decanoyl-homoserine lactone.GIF
Dodecanoyl-homoserine lactone C12HSL Synthetic Sigma Aldrich (#17247) Dodecanoyl-homoserine lactone.GIF
Tetradecanoyl-homoserine lactone C14HSL Synthetic Sigma Aldrich (#10937) Tetradecanoyl-homoserine lactone.GIF

Related Pages

References

<biblio>

  1. Engebrecht pmid=6377310
  2. Dong pmid=10716724
  3. Collins pmid=15660998

</biblio>