Pilus retraction powers bacterial twitching motility

  title={Pilus retraction powers bacterial twitching motility},
  author={Alexey J. Merz and Magdalene Maggie So and Michael P. Sheetz},
Twitching and social gliding motility allow many Gram negative bacteria to crawl along surfaces, and are implicated in a wide range of biological functions. Type IV pili (Tfp) are required for twitching and social gliding, but the mechanism by which these filaments promote motility has remained enigmatic. Here we use laser tweezers to show that Tfp forcefully retract. Neisseria gonorrhoeae cells that produce Tfp actively crawl on a glass surface and form adherent microcolonies. When laser… 

Pseudomonas aeruginosa orchestrates twitching motility by sequential control of type IV pili movements

Interferometric scattering microscopy enables the imaging of type IV pili extension, attachment, retraction and detachment dynamics, highlighting how the retraction motor PilT and its partner ATPase PilU coordinate their activities during twitching motility.

Cooperative Retraction of Bundled Type IV Pili Enables Nanonewton Force Generation

It is proposed that TFP retraction can be synchronized through bundling, that Tfp bundle retractioncan generate forces in the nanonewton range in vivo, and that such high forces could affect infection.

Motor Properties of PilT-Independent Type 4 Pilus Retraction in Gonococci

It is proposed that bacteria encode for retraction ATPases when T4P have to generate high force supporting functions like twitching motility, triggering host cell response, or fluidizing colonies.

Bacteria use type-IV pili to slingshot on surfaces

A novel two-point tracking algorithm is developed that shows that TFP-mediated crawling in Pseudomonas aeruginosa consistently alternates between two distinct actions: a translation of constant velocity and a combined translation-rotation that is approximately 20× faster in instantaneous velocity.

Bacterial twitching motility is coordinated by a two-dimensional tug-of-war with directional memory.

A combined theoretical and experimental approach is used to test the hypothesis that multiple pili of Neisseria gonorrhoeae are coordinated through a tug-of-war, and directional memory is confirmed in the form of bursts of pilus retractions.

Direct observation of extension and retraction of type IV pili

  • J. SkerkerH. Berg
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 2001
Type IV pili are linear actuators that extend, attach at their distal tips, exert substantial force, and retract, and are required for twitching motility in Pseudomonas aeruginosa and Neisseria gonorrhoeae.

Weapons of mass retraction

This review focuses on recent discoveries relating to the assembly and function of T4P in generation of twitching motility, involving retractable pili belonging to the F‐like subgroup of the type IV secretion family.

Mechanotaxis directs Pseudomonas aeruginosa twitching motility

The results demonstrate that sensory systems, whose input often remains elusive, can sense mechanical signals to actively steer motility and establish a signaling principle shared with higher-order organisms, identifying a conserved strategy to transduce spatially resolved signals.

Type IV pili and twitching motility.

  • J. Mattick
  • Biology
    Annual review of microbiology
  • 2002
Twitching motility is a flagella-independent form of bacterial translocation over moist surfaces that is important in host colonization by a wide range of plant and animal pathogens, as well as in the formation of biofilms and fruiting bodies.

PilT2 enhances the speed of gonococcal type IV pilus retraction and of twitching motility

The speed of single T4P retraction was reduced by a factor of ≈ 2 in a pilT2 deletion strain, whereas pilU deletion showed a minor effect and the maximum force and the probability for switching from retraction to elongation under application of high force were not significantly affected.



Type IV pili and cell motility

Type IV pili mediate the movement of bacteria over surfaces without the use of flagella, and participate in cell–cell interactions, pathogenesis, biofilm formation, natural DNA uptake, auto‐aggregation of cells and development.

Evidence for the retraction of Pseudomonas aeruginosa RNA phage pili.

  • D. E. Bradley
  • Biology
    Biochemical and biophysical research communications
  • 1972

PilT mutations lead to simultaneous defects in competence for natural transformation and twitching motility in piliated Neisseria gonorrhoeae

It is shown here that gonococcal pilT mutants constructed in vitro no longer display twitching motility, and that they have concurrently lost the ability to undergo natural transformation, despite the expression of structurally and morphologically normal Tfp.

Static and dynamic lengths of neutrophil microvilli.

In contrast to a rigid or nonextendible microVillus, both microvillus extension and tether formation can decrease the pulling force imposed on the adhesive bonds, and thus prolonging the persistence of the bonds at high physiological shear stresses.

Flagellar and twitching motility are necessary for Pseudomonas aeruginosa biofilm development

The isolation and characterization of mutants of Pseudomonas aeruginosa PA14 defective in the initiation of biofilm formation on an abiotic surface, polyvinylchloride (PVC) plastic are reported and evidence that microcolonies form by aggregation of cells present in the monolayer is presented.

Motility powered by supramolecular springs and ratchets.

Not all biological movements are caused by molecular motors sliding along filaments or tubules, but the viscous and fluctuating cellular environment and the mechanochemistry of soft biological systems constrain the modes of motion generated and the mechanisms for energy storage, control, and release.

Detection of sub-8-nm movements of kinesin by high-resolution optical-trap microscopy.

The distribution of magnitudes reveals that kinesin not only undergoes discrete 8-nm movements, in agreement with previous work, but also frequently exhibits smaller movements of about 5 nm, which is a possible explanation for these unexpected smaller movements.

Retraction of F Pili

The disappearance of F pili on Escherichia coli cells in the presence of 10(-2) M NaCN was studied by electron microscopy and serum-blocking power and suggests that the tips of retracted pili are exposed.