Novel paraoxonase 2-dependent mechanism mediating the biological effects of the Pseudomonas aeruginosa quorum-sensing molecule N-(3-oxo-dodecanoyl)-l-homoserine lactone

Sven Horke, Junhui Xiao, Eva Maria Schütz, Gerald L. Kramer, Petra Wilgenbus, Ines Witte, Moritz Selbach, John F. Teiber

Research output: Contribution to journalArticle

12 Scopus citations


Pseudomonas aeruginosa produces N-(3-oxo-dodecanoyl)-L-homoserine lactone (3OC12), a crucial signaling molecule that elicits diverse biological responses in host cells thought to subvert immune defenses. The mechanism mediating many of these responses remains unknown. The intracellular lactonase paraoxonase 2 (PON2) hydrolyzes and inactivates 3OC12 and is therefore considered a component of host cells that attenuates 3OC12-mediated responses. Here, we demonstrate in cell lines and in primary human bronchial epithelial cells that 3OC12 is rapidly hydrolyzed intracellularly by PON2 to 3OC12 acid, which becomes trapped and accumulates within the cells. Subcellularly, 3OC12 acid accumulated within the mitochondria, a compartment where PON2 is localized. Treatment with 3OC12 caused a rapid PON2-dependent cytosolic and mitochondrial pH decrease, calcium release, and phosphorylation of stress signaling kinases. The results indicate a novel, PON2-dependent intracellular acidification mechanism by which 3OC12 can mediate its biological effects. Thus, PON2 is a central regulator of host cell responses to 3OC12, acting to decrease the availability of 3OC12 for receptor-mediated effects and acting to promote effects, such as calcium release and stress signaling, via intracellular acidification.

Original languageEnglish (US)
Pages (from-to)3369-3380
Number of pages12
JournalInfection and Immunity
Issue number9
StatePublished - 2015


ASJC Scopus subject areas

  • Immunology
  • Microbiology
  • Parasitology
  • Infectious Diseases

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