Type IV pilus biogenesis in <i>Neisseria meningitidis</i>: PilW is involved in a step occurring after pilus assembly, essential for fibre stability and function

Carbonnelle, Étienne; Hélaine, Sophie; Prouvensier, Laure; Nassif, Xavier; Pelicic, Vladimir

doi:10.1111/j.1365-2958.2004.04364.x

Cited by 132 publications

(209 citation statements)

References 38 publications

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“…To analyze this colocalization in more detail, we examined bacteria by immuno-transmission electron microscopy (TEM) using the same anti-PilX antibody. The number of gold particles is dramatically smaller than in previous experiments in which pilin was detected by using the 20D9 antibody (24), which is consistent with our immunoblot estimate that PilX represents 3% of total pilus proteins (data not shown), or Ϸ30 PilX monomers per 1,000-subunit filament. No labeling was seen for the pilX mutant (Fig.…”

Section: Resultssupporting

confidence: 76%

3D structure/function analysis of PilX reveals how minor pilins can modulate the virulence properties of type IV pili

Hélaine

Dyer

Nassif

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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108

144

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Type IV pili (Tfp) are widespread filamentous bacterial organelles that mediate multiple virulence-related phenotypes. They are composed mainly of pilin subunits, which are processed before filament assembly by dedicated prepilin peptidases. Other proteins processed by these peptidases, whose molecular nature and mode of action remain enigmatic, play critical roles in Tfp biology. We have performed a detailed structure/function analysis of one such protein, PilX from Neisseria meningitidis, which is crucial for formation of bacterial aggregates and adhesion to human cells. The x-ray crystal structure of PilX reveals the ␣/␤ roll fold shared by all pilins, and we show that this protein colocalizes with Tfp. These observations suggest that PilX is a minor, or low abundance, pilin that assembles within the filaments in a similar way to pilin. Deletion of a PilX distinctive structural element, which is predicted to be exposed on the filament surface, abolishes aggregation and adhesion. Our results support a model in which surface-exposed motifs in PilX subunits stabilize bacterial aggregates against the disruptive force of pilus retraction and illustrate how a minor pilus component can enhance the functional properties of pili of rather simple composition and structure.adhesion ͉ aggregation ͉ pilus retraction ͉ protein crystallography

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Section: Resultssupporting

confidence: 76%

3D structure/function analysis of PilX reveals how minor pilins can modulate the virulence properties of type IV pili

Hélaine

Dyer

Nassif

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

108

144

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“…The effect of the magellan-4 insertion in this gene on S motility could be direct, but it is quite possible that this insertion affects the expression of the adjacent MXAN0359-MXAN0362 genes. These four genes are predicted to encode homologs of the Pseudomonas aeruginosa genes fimT, pilW, pilV, and pilY1, which contribute to the stability of type IV pili Mattick 1995, 1997;Alm et al 1996;Carbonnelle et al 2005). The second of these is in a gene, MXAN3759, predicted to encode one of two propionyl-CoA carboxylases made by M. xanthus (Kimura et al 1997).…”

Section: Resultsmentioning

confidence: 99%

Transposon Insertions ofmagellan-4That Impair Social Gliding Motility inMyxococcus xanthus

Youderian

Hartzell

2006

Genetics

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Myxococcus xanthus has two different mechanisms of motility, adventurous (A) motility, which permits individual cells to glide over solid surfaces, and social (S) motility, which permits groups of cells to glide. To identify the genes involved in S-gliding motility, we mutagenized a DaglU (A ÿ ) strain with the defective transposon, magellan-4, and screened for S ÿ mutants that form nonmotile colonies. Sequence analysis of the sites of the magellan-4 insertions in these mutants and the alignment of these sites with the M. xanthus genome sequence show that two-thirds of these insertions lie within 27 of the 37 nonessential genes known to be required for social motility, including those necessary for the biogenesis of type IV pili, exopolysaccharide, and lipopolysaccharide. The remaining insertions also identify 31 new, nonessential genes predicted to encode both structural and regulatory determinants of S motility. These include three tetratricopeptide repeat proteins, several regulators of transcription that may control the expression of genes involved in pilus extension and retraction, and additional enzymes involved in polysaccharide metabolism. Three insertions that abolish S motility lie within genes predicted to encode glycolytic enzymes, suggesting that the signal for pilus retraction may be a simple product of exopolysaccharide catabolism.

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“…The Tfp filament is composed of helical polymers of pilin subunits (Craig et al, 2006;Parge et al, 1995) and minor proteins (Carbonnelle et al, 2005;Winther-Larsen et al, 2005). Tfp participate in important biological processes such as DNA uptake/genetic exchange, twitching motility, attachment, and host cell signalling (Mattick, 2002;.…”

Section: Introductionmentioning

confidence: 99%

Influence of type IV pilus retraction on the architecture of the Neisseria gonorrhoeae-infected cell cortex

et al. 2009

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Early in infection, Neisseria gonorrhoeae can be observed to attach to the epithelial cell surface as microcolonies and induce dramatic changes to the host cell cortex. We tested the hypothesis that type IV pili (Tfp) retraction plays a role in the ultrastructure of both the host cell cortex and the bacterial microcolony. Using serial ultrathin sectioning, transmission electron microscopy and 3D reconstruction of serial 2D images, we have obtained what we believe to be the first 3D reconstructions of the N. gonorrhoeae-host cell interface, and determined the architecture of infected cell microvilli as well as the attached microcolony. Tfp connect both wild-type (wt) and Tfp retraction-deficient bacteria with each other, and with the host cell membrane. Tfp fibres and microvilli form a lattice in the wt microcolony and at its periphery. Wt microcolonies induce microvilli formation and increases of surface area, leading to an approximately ninefold increase in the surface area of the host cell membrane at the site of attachment. In contrast, Tfp retractiondeficient microcolonies do not affect these parameters. Wt microcolonies had a symmetrical, dome-shaped structure with a circular 'footprint', while Tfp retraction-deficient microcolonies were notably less symmetrical. These findings support a major role for Tfp retraction in microvilli and microcolony architecture. They are consistent with the biophysical attributes of Tfp and the effects of Tfp retraction on epithelial cell signalling. INTRODUCTIONNeisseria gonorrhoeae (the gonococcus, or GC) remains a significant public health concern. The Gram-negative diplococcus causes a million cases of gonorrhoea annually in Western Europe and North America, and over 62 million cases worldwide (World Health Organization). Humans are the only known reservoir for GC. The exquisite tropism of GC for man and the ability of GC to establish a carrier state (Turner et al., 2002) reflect a highly evolved relationship between pathogen and host.Gonococcal attachment is promoted by type IV pili (Tfp), peritrichous fibres that are 6 nm in width and up to several micrometres in length. The Tfp filament is composed of helical polymers of pilin subunits (Craig et al., 2006;Parge et al., 1995) and minor proteins (Carbonnelle et al., 2005;Winther-Larsen et al., 2005). Tfp participate in important biological processes such as DNA uptake/genetic exchange, twitching motility, attachment, and host cell signalling (Mattick, 2002;. These activities require, or are enhanced by, the retraction of Tfp fibres (Wolfgang et al., 2000).Gonococcal Tfp retraction is an activity that requires PilT, the Tfp retraction motor subunit (Wolfgang et al., 1998). Retracting Tfp generate strong 'pull' forces, ranging from 50 picoNewtons (pN) to 1 nanoNewton (nN) (Biais et al., 2008;Opitz et al., 2009). Repeated cycles of Tfp extension, substrate attachment and Tfp retraction allow GC to crawl over surfaces and aggregate into microcolonies. Tfp retraction from bacteria in a microcolony allows the community to craw...

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Type IV pilus biogenesis in Neisseria meningitidis: PilW is involved in a step occurring after pilus assembly, essential for fibre stability and function

Cited by 132 publications

References 38 publications

3D structure/function analysis of PilX reveals how minor pilins can modulate the virulence properties of type IV pili

3D structure/function analysis of PilX reveals how minor pilins can modulate the virulence properties of type IV pili

Transposon Insertions ofmagellan-4That Impair Social Gliding Motility inMyxococcus xanthus

Influence of type IV pilus retraction on the architecture of the Neisseria gonorrhoeae-infected cell cortex

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