title: Dissection of the promoter/operator region and evaluation of N-acylhomoserine lactone mediated transcriptional regulation of elastase expression in Pseudomonas aeruginosa.
abstract: In Pseudomonas aeruginosa, expression of the lasB gene which codes for the metalloprotease, elastase, depends on small diffusible N-acylhomoserine lactones. lasB expression is regulated through the interactions of N-3-oxododecanoyl-L-homoserine lactone and N-butanoyl-L-homoserine lactone with the transcriptional activators LasR and VsmR(RhlR), respectively. To investigate lasB expression further, we first located the transcriptional start site to a position 141 bp upstream from the translational start site. Using this information, we constructed a series of plasmids containing consecutive 5' deletions of the upstream region of lasB fused to a promoterless chloramphenicol acetyltransferase reporter gene. The results obtained indicate that three regions are required for efficient transcription of lasB; a 35 bp palindromic sequence located at +26 to +60 bp upstream from the translation start site, and two regions located upstream of the transcription start site, at -135 to -85 bp and -63 to -26 bp, respectively. Deletion of the latter region results in the loss of both N-butanoyl-L-homoserine lactone- and N-3-oxododecanoyl-L-homoserine lactone-mediated stimulation of lasB expression and provides further support for the role of this operator site as a target for either or both LasR and VsmR.
authors.affiliation: Department of Bacteriology, Yokohama City University School of Medicine, Japan. jfukusim@med.yokohama-cu.ac.jp
authors.forename: J
authors.initials: J
authors.lastname: Fukushima
authors.forename: T
authors.initials: T
authors.lastname: Ishiwata
authors.forename: Z
authors.initials: Z
authors.lastname: You
authors.forename: T
authors.initials: T
authors.lastname: Ishii
authors.forename: T
authors.initials: T
authors.lastname: Shigematsu
authors.forename: M
authors.initials: M
authors.lastname: Kurata
authors.forename: S
authors.initials: S
authors.lastname: Chikumaru-Fujita
authors.forename: B W
authors.initials: BW
authors.lastname: Bycroft
authors.forename: G S
authors.initials: GS
authors.lastname: Stewart
authors.forename: S
authors.initials: S
authors.lastname: Kawamoto
authors.forename: K
authors.initials: K
authors.lastname: Morihara
authors.forename: P
authors.initials: P
authors.lastname: Williams
authors.forename: K
authors.initials: K
authors.lastname: Okuda
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000032:analysis; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D008666:Metalloendopeptidases / Q000235:genetics; D008969:Molecular Sequence Data; D010196:Pancreatic Elastase / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000201:enzymology / Q000235:genetics*; D011994:Recombinant Proteins / Q000235:genetics; D014158:Transcription, Genetic / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; C095458:EsaI protein, Erwinia stewartii; D011994:Recombinant Proteins; D015500:Chloramphenicol O-Acetyltransferase; D010196:Pancreatic Elastase; D008666:Metalloendopeptidases; C043859:pseudolysin, Pseudomonas aeruginosa