MorA defines a new class of regulators affecting flagellar development and biofilm formation in diverse Pseudomonas species.
Assembly of bacterial flagella is developmentally important during both planktonic cell growth and biofilm formation. Flagellar biogenesis is complex, requiring coordinated expression of over 40 genes, and normally commences during the log-to-stationary transition phase. We describe here a novel membrane-localized regulator, MorA, that controls the timing of flagellar development and affects motility, chemotaxis, and biofilm formation in Pseudomonas putida. MorA is conserved among diverse Pseudomonas species, and homologues are present in all Pseudomonas genomes sequenced thus far. In P. putida, the absence of MorA derepresses flagellar development, which leads to constitutive formation of flagella in the mutant cells in all growth phases. In Pseudomonas aeruginosa, the absence of MorA led to a reduction in biofilm formation. However, unlike the motility of P. putida, the motility of the P. aeruginosa mutants was unaffected. Our data illustrate a novel developmentally regulated sensory and signaling pathway for several properties required for virulence and ecological fitness of Pseudomonas species.
Department of Biological Sciences, National University of Singapore, 10 Science Drive 4, Singapore 117543.
Weng-Keong
WK
Choy
Lian
L
Zhou
Chris Kiu-Choong
CK
Syn
Lian-Hui
LH
Zhang
Sanjay
S
Swarup
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D002462:Cell Membrane / Q000378:metabolism; D002633:Chemotaxis; D005407:Flagella / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009068:Movement; D009154:Mutation; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D016958:Pseudomonas putida / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology
D001426:Bacterial Proteins; D008565:Membrane Proteins