title: Pseudomonas aeruginosa cupA-encoded fimbriae expression is regulated by a GGDEF and EAL domain-dependent modulation of the intracellular level of cyclic diguanylate.
abstract: Cyclic-diguanylate (c-di-GMP) is a widespread bacterial signal molecule that plays a major role in the modulation of cellular surface components, such as exopolysaccharides and fimbriae, and in the establishment of a sessile life style. Here, we report that intracellular c-di-GMP levels influence cupA-encoded fimbriae expression in Pseudomonas aeruginosa. In an autoaggregative P. aeruginosa small colony variant (SCV) CupA fimbriae and the intracellular c-di-GMP concentration were found to be enhanced as compared with the clonal wild-type. The SCV morphology and the expression of CupA fimbriae were dependent on a functional PA1120 and morA gene both encoding a GGDEF domain. Overexpression of the GGDEF domain protein PA1120 complemented the PA1120 and the morA mutant with respect to CupA fimbriae expression. In agreement with these findings, overexpression of the EAL domain containing phenotypic variance regulator (PvrR) in the SCV resulted in a decreased intracellular level of c-di-GMP, a reduced cupA fimbriae expression and a switch to wild-type colony morphology.
authors.affiliation: Division of Cell Biology and Immunology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
authors.forename: Andree
authors.initials: A
authors.lastname: Meissner
authors.forename: Verena
authors.initials: V
authors.lastname: Wild
authors.forename: Roger
authors.initials: R
authors.lastname: Simm
authors.forename: Manfred
authors.initials: M
authors.lastname: Rohde
authors.forename: Christian
authors.initials: C
authors.lastname: Erck
authors.forename: Florian
authors.initials: F
authors.lastname: Bredenbruch
authors.forename: Michael
authors.initials: M
authors.lastname: Morr
authors.forename: Ute
authors.initials: U
authors.lastname: Römling
authors.forename: Susanne
authors.initials: S
authors.lastname: Häussler
mesh_terms: D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000378:metabolism; D036781:Fimbriae Proteins / Q000096:biosynthesis* / Q000235:genetics; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D010641:Phenotype; D017434:Protein Structure, Tertiary; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*