title: The response regulator LetA regulates the stationary-phase stress response in Legionella pneumophila and is required for efficient infection of Acanthamoeba castellanii.
abstract: In order to identify a potential regulator of virulence gene expression in Legionella pneumophila, the L. pneumophila homologue of the response regulator GacA, LetA, was identified and cloned, facilitating the generation of a L. pneumophila letA insertion mutant. The L. pneumophila letA insertion mutant was more sensitive to oxidative and acid stress than the wild-type. The letA mutant exhibited reduced infectivity and was defective for intracellular growth within Acanthamoeba castellanii. Transcription of the rpoS and dotA genes was reduced in the letA mutant. Our data indicate that the response regulator LetA functions as a regulator of the stationary-phase stress response in L. pneumophila and is required for efficient replication within A. castellanii.
authors.affiliation: Department of Medical Microbiology and Hygiene, University of Ulm, Robert-Koch-Str. 8, D-89081, Ulm, Germany.
authors.forename: Damien
authors.initials: D
authors.lastname: Lynch
authors.forename: Nicole
authors.initials: N
authors.lastname: Fieser
authors.forename: Karin
authors.initials: K
authors.lastname: Glöggler
authors.forename: Vera
authors.initials: V
authors.lastname: Forsbach-Birk
authors.forename: Reinhard
authors.initials: R
authors.lastname: Marre
mesh_terms: D000048:Acanthamoeba / Q000378:metabolism / Q000382:microbiology*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D003001:Cloning, Molecular; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D016952:Legionella pneumophila / Q000235:genetics / Q000472:pathogenicity*; D016254:Mutagenesis, Insertional
chemical_list: D001426:Bacterial Proteins; C068355:CcdA protein, Bacteria; C091100:GacA protein, Bacteria