Skip to main content
padlock icon - secure page this page is secure

Free Content Phosphorylation signalling through the Legionella quorum sensing histidine kinases LqsS and LqsT converges on the response regulator LqsR

Download Article:
The environmental bacterium L egionella pneumophila is the causative agent of Legionnaires' disease, a life‐threatening pneumonia. For cell–cell communication the bacteria employ the autoinducer LAI‐1 (3‐hydroxypentadecane‐4‐one), which is produced and detected by the Lqs (L egionella quorum sensing) system. The system comprises the autoinducer synthase LqsA, the putative sensor kinases LqsS and LqsT, and the prototypic response regulator LqsR. Lqs‐regulated processes include L . pneumophila‐phagocyte interactions, production of extracellular filaments, and natural competence. Using biochemical approaches we show here that LqsS and LqsT are autophosphorylated by [γ‐32P]‐ATP at a conserved histidine residue (H200 or H204) located in their cytoplasmic histidine kinase domain. Pull‐down assays revealed that LqsS and LqsT are bound by LqsR or phospho‐LqsR. Dependent on the conserved receiver domain aspartate (D108), the response regulator prevented autophosphorylation of both sensor kinases by catalysing the dephosphorylation of phospho‐LqsS or phospho‐LqsT. Moreover, LqsR formed dimers upon phosphorylation at D108 by either acetyl‐phosphate or phospho‐LqsT. Finally, upon heterologous production in E scherichia coli, LqsT (but not LqsS) was autophosphorylated by ATP, and LqsR prevented the autophosphorylation by catalysing the dephosphorylation of phospho‐LqsT. In summary, these results indicate that phosphorylation signalling through the L egionella quorum sensing histidine kinases LqsS and LqsT converges on the response regulator LqsR.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Document Type: Research Article

Publication date: June 1, 2014

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more