Activation of the Pseudomonas aeruginosa type III secretion system requires an intact pyruvate dehydrogenase aceAB operon.

ABSTRACT: Pseudomonas aeruginosa clinical cystic fibrosis isolate CHA was mutagenized with Tn5Tc to identify new genes involved in type III secretion system (TTSS)-dependent cytotoxicity toward human polymorphonuclear neutrophils. Among 25 mutants affected in TTSS function, 14 contained the insertion at different positions in the aceAB operon encoding the PDH-E1 and -E2 subunits of pyruvate dehydrogenase. In PDH mutants, no transcriptional activation of TTSS genes in response to calcium depletion occurred. Expression in trans of ExsA restored TTSS function and cytotoxicity.

SUBMITTER: Dacheux D 

PROVIDER: S-EPMC128050 | biostudies-literature | 2002 Jul

REPOSITORIES: biostudies-literature