title: The LapG protein plays a role in Pseudomonas aeruginosa biofilm formation by controlling the presence of the CdrA adhesin on the cell surface.
abstract: Pseudomonas aeruginosa is a clinically relevant species involved in biofilm-based chronic infections. We provide evidence that the P. aeruginosa LapG protein functions as a periplasmic protease that can cleave the protein adhesin CdrA off the cell surface, and thereby plays a role in biofilm formation and biofilm dispersal. The P. aeruginosa LapG protein is shown to be a functional homolog of the Pseudomonas putida LapG protein which has previously been shown to function as a periplasmic protease that targets the surface adhesin LapA. Transposon mutagenesis and characterization of defined knockout mutants provided evidence that the CdrA adhesin is a target of LapG in P. aeruginosa. A wspF lapG double mutant was hyper-aggregating and hyper biofilm forming, whereas a wspF lapG cdrA triple mutant lost these phenotypes. In addition, western blot detection of CdrA in culture supernatants and whole-cell protein fractions showed that CdrA was retained in the whole-cell protein fraction when LapG was absent, whereas it was found in the culture supernatant when LapG was present. The finding that CdrA is a target of LapG in P. aeruginosa is surprising because CdrA has no homology to LapA.
authors.affiliation: Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark.
authors.forename: Morten
authors.initials: M
authors.lastname: Rybtke
authors.affiliation: Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Berthelsen
authors.affiliation: Singapore Center on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
authors.forename: Liang
authors.initials: L
authors.lastname: Yang
authors.affiliation: Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark.|Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Niels
authors.initials: N
authors.lastname: Høiby
authors.affiliation: Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark.|Singapore Center on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
authors.forename: Michael
authors.initials: M
authors.lastname: Givskov
authors.affiliation: Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark.
authors.forename: Tim
authors.initials: T
authors.lastname: Tolker-Nielsen
mesh_terms: D018829:Adhesins, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D018441:Biofilms; D002462:Cell Membrane / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D011552:Pseudomonas Infections / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D016415:Sequence Alignment
chemical_list: D018829:Adhesins, Bacterial; C551088:CdrA protein, Pseudomonas aeruginosa
keywords: Adhesin; Pseudomonas.; biofilm; c-di-GMP; protease