title: Role of luxS in Bacillus anthracis growth and virulence factor expression.
abstract: Quorum-sensing (QS), the regulation of bacterial gene expression in response to changes in cell density, involves pathways that synthesize signaling molecules (auto-inducers). The luxS/AI-2-mediated QS system has been identified in both gram-positive and gram-negative bacteria. Bacillus anthracis, the etiological agent of anthrax, possesses genes involved in luxS/AI-2-mediated QS, and deletion of luxS in B. anthracis Sterne strain 34F2 results in inhibition of AI-2 synthesis and a growth defect. In the present study, we created a ΔluxS B. anthracis strain complemented in trans by insertion of a cassette, including luxS and a gene encoding erythromycin resistance, into the truncated plcR regulator locus. The complemented ΔluxS strain has restored AI-2 synthesis and wild-type growth. A B. anthracis microarray study revealed consistent differential gene expression between the wild-type and ΔluxS strain, including downregulation of the B. anthracis S-layer protein gene EA1 and pXO1 virulence genes. These data indicate that B. anthracis may use luxS/AI-2-mediated QS to regulate growth, density-dependent gene expression and virulence factor expression.
authors.affiliation: Pathogen Functional Genomics Resource Center, J. Craig Venter Institute, Rockville, MD, USA. mjones@jcvi.org
authors.forename: Marcus B
authors.initials: MB
authors.lastname: Jones
authors.forename: Scott N
authors.initials: SN
authors.lastname: Peterson
authors.forename: Rosslyn
authors.initials: R
authors.lastname: Benn
authors.forename: John C
authors.initials: JC
authors.lastname: Braisted
authors.forename: Behnam
authors.initials: B
authors.lastname: Jarrahi
authors.forename: Kenneth
authors.initials: K
authors.lastname: Shatzkes
authors.forename: Dacheng
authors.initials: D
authors.lastname: Ren
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Wood
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Blaser
mesh_terms: D001408:Bacillus anthracis / Q000235:genetics / Q000254:growth & development* / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D013437:Carbon-Sulfur Lyases / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006714:Homoserine / Q000031:analogs & derivatives / Q000378:metabolism; D007783:Lactones / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D053038:Quorum Sensing; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D007783:Lactones; D008562:Membrane Glycoproteins; C091088:N-octanoylhomoserine lactone; C055764:S-layer proteins; D037521:Virulence Factors; D006714:Homoserine; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria