A systematic genetic analysis in Neisseria meningitidis defines the Pil proteins required for assembly, functionality, stabilization and export of type IV pili
File(s)
Accepted version
Author(s)
Carbonnelle, E
Helaine, S
Nassif, X
Pelicic, V
Type
Journal Article
Abstract
Although type IV pili (Tfp) are among the commonest virulence factors in bacteria, their biogenesis by complex machineries of 12–15 proteins, and thereby their function remains poorly understood. Interestingly, some of these proteins were reported to merely antagonize the retraction of the fibres powered by PilT, because piliation could be restored in their absence by a mutation in the pilT gene. The recent identification of the 15 Pil proteins dedicated to Tfp biogenesis in Neisseria meningitidis offered us the unprecedented possibility to define their exact contribution in this process. We therefore systematically introduced a pilT mutation into the corresponding non-piliated mutants and characterized them for the rescue of Tfp and Tfp-mediated virulence phenotypes. We found that in addition to the pilin, the main constituent of Tfp, only six Pil proteins were required for the actual assembly of the fibres, because apparently normal fibres were restored in the remaining mutants. Restored fibres were surface-exposed, except in the pilQ/T mutant in which they were trapped in the periplasm, suggesting that the PilQ secretin was the sole Pil component necessary for their emergence on the surface. Importantly, although in most mutants the restored Tfp were not functional, the pilG/T and pilH/T mutants could form bacterial aggregates and adhere to human cells efficiently, suggesting that Tfp stabilization and functional maturation are two discrete steps. These findings have numerous implications for understanding Tfp biogenesis/function and provide a useful groundwork for the characterization of the precise function of each Pil protein in this process.
Date Issued
2006-09-01
Date Acceptance
2006-07-19
Citation
Molecular Microbiology, 2006, 61 (6), pp.1510-1522
ISSN
1365-2958
Publisher
Wiley
Start Page
1510
End Page
1522
Journal / Book Title
Molecular Microbiology
Volume
61
Issue
6
Copyright Statement
This is the peer reviewed version of the following article: Carbonnelle, E., Helaine, S., Nassif, X. and Pelicic, V. (2006), A systematic genetic analysis in Neisseria meningitidis defines the Pil proteins required for assembly, functionality, stabilization and export of type IV pili. Molecular Microbiology, 61: 1510–1522., which has been published in final form at https://dx.doi.org/10.1111/j.1365-2958.2006.05341.x. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
Subjects
Science & Technology
Life Sciences & Biomedicine
Biochemistry & Molecular Biology
Microbiology
BIOCHEMISTRY & MOLECULAR BIOLOGY
MICROBIOLOGY
ENTEROPATHOGENIC ESCHERICHIA-COLI
GRAM-NEGATIVE BACTERIA
PSEUDOMONAS-AERUGINOSA
TWITCHING MOTILITY
EPITHELIAL-CELLS
PATHOGENIC NEISSERIA
ANTIGENIC VARIATION
MEDIATED ADHESION
BIOGENESIS
GONORRHOEAE
Publication Status
Published