Cyclic AMP-Independent Control of Twitching Motility in Pseudomonas aeruginosa

Buensuceso, Ryan N. C.; Daniel-Ivad, Martin; Kilmury, Sara L.N.; Leighton, Tiffany L.; Harvey, Hanjeong; Howell, P. Lynne; Burrows, Lori L.

doi:10.1128/jb.00188-17

Cited by 35 publications

(30 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, in M. xanthus , the direction of twitching motility and the TFP localization pattern oscillates periodically and this process is orchestrated by the frz system, suggesting that frz regulates both motors either directly or indirectly 31 . Similarly, in P. aeruginosa , the Pil-Chp two-component system regulates pilus behaviors, both through biochemical interaction of the two response regulators PilG and PilH with the pilus machine and by transcriptional modification using the cAMP dependent transcriptional regulator Vfr 32–34 . The second messenger c-di-GMP has also been shown to interact directly with the extension motor and other components of the TFP machine 35–37 , thus resembling another interesting candidate for the regulation of the binding and unbind rates of TFP.…”

Section: Discussionmentioning

confidence: 99%

Competitive binding of independent extension and retraction motors explains the quantitative dynamics of type IV pili

Koch

Fei

Wingreen

et al. 2020

Preprint

View full text Add to dashboard Cite

10The functions of type IV pili (TFP) are mediated by cycles of extension and retraction. The 11 coordination of these cycles remains mysterious due to poor quantification of TFP dynamics. Here we 12 fluorescently label the TFP in the opportunistic pathogen Pseudomonas aeruginosa and track the full 13 extension and retraction cycles of individual TFP to quantify their dynamics. We test several models for 14 the switch between extension and retraction using quantitative experiments, biophysical modeling and 15 genetics. We invalidate the prominent hypothesis that this switch is triggered by surface contact. Instead, 16 we show that the entire repetitive cycle of extension and retraction of individual TFP is governed by the 17 stochastic binding of antagonistic extension and retraction motors and explain how this mechanism 18 quantitatively defines physiologically-important features like TFP length and their production rate. 19Interestingly, our results suggest that the major throttle of TFP production is the unbinding of the 20 retraction motor. 21 22 microns 22 . Despite the limitations of these approaches, they have led to several competing models for 42 how the switch between TFP extension and retraction is controlled. A cryo-EM study did not observe 43 motors at the base of unpiliated structures, suggesting that the motors do not remain bound after TFP 44 retraction 12 . Meanwhile, an interferometry study focusing on the longest subpopulation of TFP suggested 45 that TFP retraction is triggered by surface association 22 . However, the inability to directly visualize the 46 dynamics of the entire TFP population previously limited the ability to directly test these models. 47Here we addressed the above limitations by directly fluorescently labeling the TFP of P. 48 aeruginosa. Fluorescent labeling of TFP was first achieved with non-specific labeling of extracellular 49 proteins 23 . However, similar to the interferometry approach, this surface labeling approach led to a strong 50 halo from staining of the cell body that prevented analysis of short pili. More recently, TFP from 51Caulobacter crescentus and Vibrio cholerae were directly labeled by introducing a reactive cysteine 52 residue into the pilin sequence 24-26 . Here we apply this approach to P. aeruginosa and use it to perform 53 the first direct quantitative analysis of full TFP extension and retraction cycles of individual pili. We go 54 on to develop and test quantitative models for the behaviors we observe. We show that TFP production 55 rate, length, and dynamics can be fully explained by the mutually exclusive stochastic binding of the 56 extension and retraction motors, and that this stochasticity persists in the presence or absence of surface 57 association. 58 59 Results 60Quantifying TFP dynamics reveals that P. aeruginosa makes mostly short pili that are highly dynamic 61We fluorescently labeled the major protein of the P. aeruginosa pilus fiber (PilA) by introducing 62 a cysteine point mutation, A86C, that we then labeled with the thiol-r...

show abstract

Section: Discussionmentioning

confidence: 99%

Competitive binding of independent extension and retraction motors explains the quantitative dynamics of type IV pili

Koch

Fei

Wingreen

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…Swarming motility assays were performed as described in (54). Briefly, strains of interest were grown overnight in 5mL LB cultures at 37°C.…”

Section: Methodsmentioning

confidence: 99%

ThePseudomonas aeruginosaPilSR two-component system regulates both twitching and swimming motilities

Kilmury

Burrows

2018

Preprint

Self Cite

View full text Add to dashboard Cite

Motility is an important virulence trait for many bacterial pathogens, allowing them to position themselves in appropriate locations at appropriate times. Motility structures - pili and flagella - are also involved in sensing surface contact, which modulates pathogenicity. In Pseudomonas aeruginosa, the PilS-PilR two-component system (TCS) regulates expression of the type IV pilus (T4P) major subunit PilA, while biosynthesis of the single polar flagellum is regulated by a hierarchical system that includes the FleSR TCS. Previous studies in Geobacter sulfurreducens and Dichelobacter nodosus implicated PilR in regulation of non-T4P-related genes, including some involved in flagellar biosynthesis. Here we used RNAseq analysis to identify genes in addition to pilA with changes in expression in the absence of pilR. Among these were 10 genes inversely dysregulated by loss of pilA versus pilR, even though both pilA and pilR mutants lack T4P and pilus-related phenotypes. The products of those genes - many of which were hypothetical - may be important for virulence and surface-associated behaviours, as mutants had altered swarming motility, biofilm formation, type VI secretion, and pathogenicity in a nematode model. Further, the PilSR TCS positively regulated transcription of fleSR, and thus many genes in the FleSR regulon. As a result, pilSR deletion mutants had defects in swimming motility that were independent of the loss of PilA. Together these data suggest that in addition to controlling T4P expression, PilSR have a broader role in the regulation of P. aeruginosa motility and surface sensing behaviours.

show abstract

“…On the other hand, twitching motility is controlled by type IV pili (Buensuceso et al . ). Furthermore, P. aeruginosa is ubiquitous in nature and excessive use of antibiotics may exert selection pressure leading to the emergence of superbugs.…”

Section: Introductionmentioning

confidence: 97%

“…Rhamnolipids are important for the formation of water channels in mature biofilms and it also affects the swarming motility which is directly implicated in the biofilm development (Davey et al 2003). On the other hand, twitching motility is controlled by type IV pili (Buensuceso et al 2017). Furthermore, P. aeruginosa is ubiquitous in nature and excessive use of antibiotics may exert selection pressure leading to the emergence of superbugs.…”

Section: Introductionmentioning

confidence: 99%

Anti‐biofilm and cytoprotective activities of quercetin againstPseudomonas aeruginosaisolates

Vipin

Mujeeburahiman

Ashwini

et al. 2019

Lett Appl Microbiol

View full text Add to dashboard Cite

Increase in infection with multidrug resistant Pseudomonas aeruginosa is a serious global challenge in healthcare. Pseudomonas aeruginosa is capable of causing human infection in various sites and complicates the infection due to its virulence factors. This study was aimed to investigate the effect of quercetin, a dietary flavonoid against the virulence factors of P. aeruginosa and its cell protective effects on epithelial cells. Bactericidal activity, anti‐biofilm activity and effect on different virulence factors were carried out using standard methods by using five P. aeruginosa isolates. Cytotoxicity and cell protective effect of quercetin was evaluated by trypan blue dye exclusion assay. All the tested isolates were completely inhibited (100%) by quercetin at a concentration of 500 μg ml–1. It showed significant (P < 0·05) inhibitory effect on virulence factors including biofilm formation and showed significant protective effect on HEK 293T cells infected with P. aeruginosa strains. This study supports the role of quercetin against P. aeruginosa, by inhibiting virulence factors as well as its cytoprotective activity during bacterial infection either by attenuating the virulence or providing direct protective effect to the host cells. Significance and Impact of the Study The increase in infections caused by opportunistic pathogen Pseudomonas aeruginosa is a serious concern in the health care system. This study describes the beneficial effects of a dietary flavonoid, quercetin against pathogenic P. aeruginosa strains and its protective effect against the P. aeruginosa infection in HEK 293T cells in vitro.

show abstract

Cyclic AMP-Independent Control of Twitching Motility in Pseudomonas aeruginosa

Cited by 35 publications

References 56 publications

Competitive binding of independent extension and retraction motors explains the quantitative dynamics of type IV pili

Competitive binding of independent extension and retraction motors explains the quantitative dynamics of type IV pili

ThePseudomonas aeruginosaPilSR two-component system regulates both twitching and swimming motilities

Anti‐biofilm and cytoprotective activities of quercetin againstPseudomonas aeruginosaisolates

Contact Info

Product

Resources

About