The alginate regulator AlgR and an associated sensor FimS are required for twitching motility in Pseudomonas aeruginosa.
Mucoid strains of Pseudomonas aeruginosa isolated from the lungs of cystic fibrosis patients produce large amounts of the exopolysaccharide alginate. AlgR has long been considered a key regulator of alginate production, but its cognate sensor has not been identified. Here we show that AlgR is required for twitching motility, which is a form of bacterial surface translocation mediated by type 4 fimbriae. Adjacent to algR we have identified a sensor gene (fimS), which is also required for twitching motility. However, FimS does not appear to be required for alginate production in mucoid strains. FimS and AlgR are representative of a new subclass of two-component transmitter-receiver regulatory systems. The alternative sigma factor AlgU also affects both alginate production and twitching motility. Therefore, these two virulence determinants appear to be closely associated and coordinately regulated.
Whitchurch
C B
CB
Centre for Molecular and Cellular Biology, University of Queensland, Brisbane, Australia.
Alm
R A
RA
Mattick
J S
JS
D000464:Alginates / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D015153:Blotting, Western; D004268:DNA-Binding Proteins; D016208:Databases, Factual; D004797:Enzyme-Linked Immunosorbent Assay; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000502:physiology*; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D009068:Movement / Q000502:physiology; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000502:physiology*; D012097:Repressor Proteins; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor; D014157:Transcription Factors
C079619:AlgU protein, Pseudomonas aeruginosa; D000464:Alginates; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D012808:Sigma Factor; D014157:Transcription Factors; C072452:algP protein, Pseudomonas aeruginosa