Single pilus motor forces exceed 100 pN

Maier, Berenike; Potter, Laura; So, Magdalene; Seifert, H. Steven; Sheetz, Michael P.

doi:10.1073/pnas.242523299

Cited by 366 publications

(348 citation statements)

References 29 publications

(28 reference statements)

Supporting

Mentioning

333

Contrasting

Unclassified

Order By: Relevance

“…Shear stress generates a force on the cell body that is parallel to the surface and is balanced by tension in TFP. We set the flow rate to generate roughly 10 pN of force, which is on the order of forces generated by TFP retraction (26).…”

Section: Mechanotransduction Requires Both Tfp Tension and Retractionmentioning

confidence: 99%

Type IV pili mechanochemically regulate virulence factors in Pseudomonas aeruginosa

Persat

Inclán

Engel

et al. 2015

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

338

367

View full text Add to dashboard Cite

Bacteria have evolved a wide range of sensing systems to appropriately respond to environmental signals. Here we demonstrate that the opportunistic pathogen Pseudomonas aeruginosa detects contact with surfaces on short timescales using the mechanical activity of its type IV pili, a major surface adhesin. This signal transduction mechanism requires attachment of type IV pili to a solid surface, followed by pilus retraction and signal transduction through the Chp chemosensory system, a chemotaxis-like sensory system that regulates cAMP production and transcription of hundreds of genes, including key virulence factors. Like other chemotaxis pathways, pili-mediated surface sensing results in a transient response amplified by a positive feedback that increases type IV pili activity, thereby promoting long-term surface attachment that can stimulate additional virulence and biofilm-inducing pathways. The methyl-accepting chemotaxis protein-like chemosensor PilJ directly interacts with the major pilin subunit PilA. Our results thus support a mechanochemical model where a chemosensory system measures the mechanically induced conformational changes in stretched type IV pili. These findings demonstrate that P. aeruginosa not only uses type IV pili for surface-specific twitching motility, but also as a sensor regulating surface-induced gene expression and pathogenicity.surface sensing | mechanotransduction | type IV pili | virulence N umerous bacterial species exhibit a range of behaviors that are specific to life on surfaces. For many pathogens, surfacespecific phenotypes are often associated with virulent activity, because many infection strategies require contact with a host (1). For example, in Pseudomonas aeruginosa, the type III secretion system, which infects by injecting toxins, requires attachment of individual cells to host-cell membranes (2). The genetic pathways that regulate P. aeruginosa secretion systems have been well characterized (3), but the environmental signals that activate these pathways remain poorly defined (4). Given the requirement for host-cell contact for efficient infection, P. aeruginosa could leverage surface contact as a signal to properly activate and coordinate pathogenicity. Indeed, our laboratory recently demonstrated that prolonged association with a solid surface contributes to P. aeruginosa pathogenicity when bacteria and host cells are forced together (5). Here we address the fundamental question of how bacteria rapidly sense surface contact and transduce this input into a cellular response over short timescales.Surface-specific behaviors require intimate contact between cells and substrate. In P. aeruginosa, contact is mediated by several adhesins, particularly type IV pili (TFP). TFP are long, motorized fimbriae that also provide cells with surface-specific twitching motility and are essential to virulence and biofilm formation (6, 7). Successive TFP extension, attachment, and retraction promote intimate association with surfaces and motility along them. Because TFP dynamically int...

show abstract

Section: Mechanotransduction Requires Both Tfp Tension and Retractionmentioning

confidence: 99%

Type IV pili mechanochemically regulate virulence factors in Pseudomonas aeruginosa

Persat

Inclán

Engel

et al. 2015

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

338

367

View full text Add to dashboard Cite

show abstract

“…While there have been several studies highlighting the importance of the PilT group of ATPases in generating the force for pilus retraction (21,25,41), little is known of the interactions of PilT with other Tfp components at the molecular level (7). A few reports describe the role of PilT in the Tfp system of Synechocystis sp.…”

Section: Discussionmentioning

confidence: 99%

“…In the gram-positive bacteria, accessories of the DNA uptake apparatus closely resemble Tfp components, including the ComG proteins of Bacillus subtilis and the Cil/Cgl proteins of Streptococcus pneumoniae (11). One particularly important component of the Tfp system is the PilT protein, essential for twitching motility and for generating the pilus retraction force required for pulling the cell along a surface (21,41). It possesses the nucleotide-binding Walker box motifs found in many NTPases (46) and is thought to cause the retraction of pili through the disassembly of subunits of the pilus filament at the expense of ATP hydrolysis (24,47).…”

mentioning

confidence: 99%

Functional Analysis of PilT from the Toxic Cyanobacterium Microcystis aeruginosa PCC 7806

et al. 2007

View full text Add to dashboard Cite

The evolution of the microcystin toxin gene cluster in phylogenetically distant cyanobacteria has been attributed to recombination, inactivation, and deletion events, although gene transfer may also be involved. Since the microcystin-producing Microcystis aeruginosa PCC 7806 is naturally transformable, we have initiated the characterization of its type IV pilus system, involved in DNA uptake in many bacteria, to provide a physiological focus for the influence of gene transfer in microcystin evolution. The type IV pilus genes pilA, pilB, pilC, and pilT were shown to be expressed in M. aeruginosa PCC 7806. The purified PilT protein yielded a maximal ATPase activity of 37.5 ؎ 1.8 nmol P i min ؊1 mg protein ؊1 , with a requirement for Mg 2؉ . Heterologous expression indicated that it could complement the pilT mutant of Pseudomonas aeruginosa, but not that of the cyanobacterium Synechocystis sp. strain PCC 6803, which was unexpected. Differences in two critical residues between the M. aeruginosa PCC 7806 PilT (7806 PilT) and the Synechocystis sp. strain PCC 6803 PilT proteins affected their theoretical structural models, which may explain the nonfunctionality of 7806 PilT in its cyanobacterial counterpart. Screening of the pilT gene in toxic and nontoxic strains of Microcystis was also performed.

show abstract

“…Grâce à un astucieux montage optique, la force que peut exercer la rétraction d'un seul pilus a été mesurée : environ 100 picoNewton (pN) [6]. Qu'est-ce donc qu'un picoNewton ?…”

Section: Spiderman Microscopiqueunclassified

“…Le pilus n'en est pas directement responsable. Un nanomoteur (la protéine PilT) localisé sans doute à la base du pilus contrôle la rétraction et la génération de force [6]. Lorsque l'on enlève génétiquement cette protéine, la bactérie possède toujours des pili, mais ils ont perdu leur dynamisme.…”

unclassified

Pili de type IV

Biais¹

2009

Med Sci (Paris)

View full text Add to dashboard Cite

Single pilus motor forces exceed 100 pN

Cited by 366 publications

References 29 publications

Type IV pili mechanochemically regulate virulence factors in Pseudomonas aeruginosa

Type IV pili mechanochemically regulate virulence factors in Pseudomonas aeruginosa

Functional Analysis of PilT from the Toxic Cyanobacterium Microcystis aeruginosa PCC 7806

Pili de type IV

Contact Info

Product

Resources

About