Functional analyses of pilin-like proteins from Francisella tularensis: complementation of type IV pilus phenotypes in Neisseria gonorrhoeae.
Accumulating evidence from a number of studies strongly suggests that proteins orthologous to those involved in type IV pili (Tfp) assembly and function are required for Francisella pathogenicity. However, the molecular mechanisms by which the components exert their influence on virulence remain poorly understood. Owing to the conservation and promiscuity of Tfp biogenesis machineries, expression of Tfp pilins in heterologous species has been used successfully to analyse organelle structure-function relationships. In this study we expressed a number of Francisella pilin genes in the Tfp-expressing pathogen Neisseria gonorrhoeae lacking its endogenous pilin subunit. Two gene products, the orthologous PilA proteins from Francisella tularensis subspecies tularensis and novicida, were capable of restoring the expression of Tfp-like appendages that were shown to be dependent upon the neisserial Tfp biogenesis machinery for surface localization. Expression of Francisella PilA pilins also partially restored competence for natural transformation in N. gonorrhoeae. This phenotype was not complemented by expression of the PulG and XcpT proteins, which are equivalent components of the related type II protein secretion system. Taken together, these findings provide compelling, although indirect, evidence of the potential for Francisella PilA proteins to express functional Tfp.
Umeå Centre for Microbial Research (UCMR) and Laboratory for Molecular Infection Medicine, Sweden (MIMS), Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden.|CBRN Defence and Security, FOI Swedish Defence Research Agency, Cementvägen 20, 901 82 Umeå, Sweden.
Emelie
E
Salomonsson
Umeå Centre for Microbial Research (UCMR) and Laboratory for Molecular Infection Medicine, Sweden (MIMS), Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden.|CBRN Defence and Security, FOI Swedish Defence Research Agency, Cementvägen 20, 901 82 Umeå, Sweden.
Åke
Å
Forsberg
Department of Molecular Biosciences, University of Oslo, 0316 Oslo, Norway.
Norbert
N
Roos
Westfälische Wilhelms-Universität Münster, Institut für Allgemeine Zoologie und Genetik, 48149 Münster, Germany.
Claudia
C
Holz
Westfälische Wilhelms-Universität Münster, Institut für Allgemeine Zoologie und Genetik, 48149 Münster, Germany.
Berenike
B
Maier
Centre for Molecular Biology and Neuroscience, University of Oslo, 0316 Oslo, Norway.|Department of Molecular Biosciences, University of Oslo, 0316 Oslo, Norway.
Michael
M
Koomey
Centre for Molecular Biology and Neuroscience, University of Oslo, 0316 Oslo, Norway.|Department of Molecular Biosciences, University of Oslo, 0316 Oslo, Norway.
Hanne C
HC
Winther-Larsen
D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D036781:Fimbriae Proteins / Q000096:biosynthesis / Q000235:genetics; D010861:Fimbriae, Bacterial / Q000378:metabolism; D005604:Francisella tularensis / Q000235:genetics* / Q000472:pathogenicity; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D006031:Glycosylation; D026901:Membrane Transport Proteins / Q000096:biosynthesis / Q000235:genetics; D009344:Neisseria gonorrhoeae / Q000235:genetics / Q000378:metabolism*; D014169:Transformation, Bacterial; D014774:Virulence
D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; C082104:XcpT protein, Pseudomonas aeruginosa; D036781:Fimbriae Proteins