scholarly journals Haloferax volcanii Flagella Are Required for Motility but Are Not Involved in PibD-Dependent Surface Adhesion

2010 ◽  
Vol 192 (12) ◽  
pp. 3093-3102 ◽  
Author(s):  
Manuela Tripepi ◽  
Saheed Imam ◽  
Mechthild Pohlschröder
Keyword(s):  
Critical Role ◽  
Type Iv Pili ◽  
Haloferax Volcanii ◽  
Surface Adhesion ◽  
Functional Roles ◽  
Bacterial Flagella ◽  
Type Iv ◽  
Type Iv Pilin ◽  
Flagellar Assembly ◽  
Bacterial Type

ABSTRACT Although the genome of Haloferax volcanii contains genes (flgA1-flgA2) that encode flagellins and others that encode proteins involved in flagellar assembly, previous reports have concluded that H. volcanii is nonmotile. Contrary to these reports, we have now identified conditions under which H. volcanii is motile. Moreover, we have determined that an H. volcanii deletion mutant lacking flagellin genes is not motile. However, unlike flagella characterized in other prokaryotes, including other archaea, the H. volcanii flagella do not appear to play a significant role in surface adhesion. While flagella often play similar functional roles in bacteria and archaea, the processes involved in the biosynthesis of archaeal flagella do not resemble those involved in assembling bacterial flagella but, instead, are similar to those involved in producing bacterial type IV pili. Consistent with this observation, we have determined that, in addition to disrupting preflagellin processing, deleting pibD, which encodes the preflagellin peptidase, prevents the maturation of other H. volcanii type IV pilin-like proteins. Moreover, in addition to abolishing swimming motility, and unlike the flgA1-flgA2 deletion, deleting pibD eliminates the ability of H. volcanii to adhere to a glass surface, indicating that a nonflagellar type IV pilus-like structure plays a critical role in H. volcanii surface adhesion.

Assembly and function of the archaeal flagellum

2011 ◽  
Vol 39 (1) ◽  
pp. 64-69 ◽  
Author(s):  
Abhrajyoti Ghosh ◽  
Sonja-Verena Albers
Keyword(s):  
Evolutionary Relationship ◽  
Type Iv Pili ◽  
Assembly Systems ◽  
Sequence Information ◽  
Type Iv ◽  
Core Proteins ◽  
Domains Of Life ◽  
Interaction Map ◽  
Archaeal Flagellum ◽  
Bacterial Type

Motility is a common behaviour in prokaryotes. Both bacteria and archaea use flagella for swimming motility, but it has been well documented that structures of the flagellum from these two domains of life are completely different, although they contribute to a similar function. Interestingly, information available to date has revealed that structurally archaeal flagella are more similar to bacterial type IV pili rather than to bacterial flagella. With the increasing genome sequence information and advancement in genetic tools for archaea, identification of the components involved in the assembly of the archaeal flagellum is possible. A subset of these components shows similarities to components from type IV pilus-assembly systems. Whereas the molecular players involved in assembly of the archaeal flagellum are being identified, the mechanics and dynamics of the assembly of the archaeal flagellum have yet to be established. Recent computational analysis in our laboratory has identified conserved highly charged loop regions within one of the core proteins of the flagellum, the membrane integral protein FlaJ, and predicted that these are involved in the interaction with the assembly ATPase FlaI. Interestingly, considerable variation was found among the loops of FlaJ from the two major subkingdoms of archaea, the Euryarchaeota and the Crenarchaeota. Understanding the assembly pathway and creating an interaction map of the molecular players in the archaeal flagellum will shed light on the details of the assembly and also the evolutionary relationship to the bacterial type IV pili-assembly systems.

scholarly journals Critical Role of ASC Inflammasomes and Bacterial Type IV Secretion System in Caspase-1 Activation and Host Innate Resistance toBrucella abortusInfection

2013 ◽  
Vol 190 (7) ◽  
pp. 3629-3638 ◽  
Author(s):  
Marco Tulio R. Gomes ◽  
Priscila C. Campos ◽  
Fernanda S. Oliveira ◽  
Patricia P. Corsetti ◽  
Karina R. Bortoluci ◽  
...  
Keyword(s):  
Critical Role ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Type Iv Secretion System ◽  
Innate Resistance ◽  
Caspase 1 ◽  
Type Iv ◽  
Bacterial Type

scholarly journals Dynamic Regulation of Bacterial Type IV Pili in Response to Light Signal

2018 ◽  
Vol 58 (4) ◽  
pp. 207-208
Author(s):  
Daisuke NAKANE ◽  
Takayuki NISHIZAKA
Keyword(s):  
Light Signal ◽  
Type Iv Pili ◽  
Dynamic Regulation ◽  
Type Iv ◽  
Bacterial Type

scholarly journals Mechanosensing of shear by Pseudomonas aeruginosa leads to increased levels of the cyclic-di-GMP signal initiating biofilm development

2017 ◽  
Vol 114 (23) ◽  
pp. 5906-5911 ◽  
Author(s):  
Christopher A. Rodesney ◽  
Brian Roman ◽  
Numa Dhamani ◽  
Benjamin J. Cooley ◽  
Parag Katira ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Envelope Protein ◽  
Intracellular Signaling ◽  
Shear Force ◽  
Type Iv Pili ◽  
Surface Adhesion ◽  
Free Swimming ◽  
Surface Attachment ◽  
Type Iv ◽  
Biofilm Development

Biofilms are communities of sessile microbes that are phenotypically distinct from their genetically identical, free-swimming counterparts. Biofilms initiate when bacteria attach to a solid surface. Attachment triggers intracellular signaling to change gene expression from the planktonic to the biofilm phenotype. For Pseudomonas aeruginosa, it has long been known that intracellular levels of the signal cyclic-di-GMP increase upon surface adhesion and that this is required to begin biofilm development. However, what cue is sensed to notify bacteria that they are attached to the surface has not been known. Here, we show that mechanical shear acts as a cue for surface adhesion and activates cyclic-di-GMP signaling. The magnitude of the shear force, and thereby the corresponding activation of cyclic-di-GMP signaling, can be adjusted both by varying the strength of the adhesion that binds bacteria to the surface and by varying the rate of fluid flow over surface-bound bacteria. We show that the envelope protein PilY1 and functional type IV pili are required mechanosensory elements. An analytic model that accounts for the feedback between mechanosensors, cyclic-di-GMP signaling, and production of adhesive polysaccharides describes our data well.

scholarly journals Archaeal flagellar ATPase motor shows ATP-dependent hexameric assembly and activity stimulation by specific lipid binding

2011 ◽  
Vol 437 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Abhrajyoti Ghosh ◽  
Sophia Hartung ◽  
Chris van der Does ◽  
John A. Tainer ◽  
Sonja-Verena Albers
Keyword(s):  
Atp Hydrolysis ◽  
Gel Filtration ◽  
Lipid Binding ◽  
Type Iv Pili ◽  
Assembly Systems ◽  
Bacterial Flagella ◽  
Type Iv ◽  
Biochemical Analyses ◽  
Archaeal Flagellum ◽  
Flagella Assembly

Microbial motility frequently depends on flagella or type IV pili. Using recently developed archaeal genetic tools, archaeal flagella and its assembly machinery have been identified. Archaeal flagella are functionally similar to bacterial flagella and their assembly systems are homologous with type IV pili assembly systems of Gram-negative bacteria. Therefore elucidating their biochemistry may result in insights in both archaea and bacteria. FlaI, a critical cytoplasmic component of the archaeal flagella assembly system in Sulfolobus acidocaldarius, is a member of the type II/IV secretion system ATPase superfamily, and is proposed to be bi-functional in driving flagella assembly and movement. In the present study we show that purified FlaI is a Mn2+-dependent ATPase that binds MANT-ATP [2′-/3′-O-(N′- methylanthraniloyl)adenosine-5′-O-triphosphate] with a high affinity and hydrolyses ATP in a co-operative manner. FlaI has an optimum pH and temperature of 6.5 and 75 °C for ATP hydrolysis. Remarkably, archaeal, but not bacterial, lipids stimulated the ATPase activity of FlaI 3–4-fold. Analytical gel filtration indicated that FlaI undergoes nucleotide-dependent oligomerization. Furthermore, SAXS (small-angle X-ray scattering) analysis revealed an ATP-dependent hexamerization of FlaI in solution. The results of the present study report the first detailed biochemical analyses of the motor protein of an archaeal flagellum.

scholarly journals Type IV pilin post-translational modifications modulate materials properties of bacterial colonies

2018 ◽  
Author(s):  
R. Zöllner ◽  
T. Cronenberg ◽  
N. Kouzel ◽  
A. Welker ◽  
M. Koomey ◽  
...  
Keyword(s):  
Local Order ◽  
Glycan Structure ◽  
Post Translational Modification ◽  
Extracellular Polymers ◽  
Post Translational Modifications ◽  
Materials Properties ◽  
Type Iv ◽  
Pilin Subunit ◽  
Type Iv Pilin ◽  
Bacterial Type

AbstractBacterial type 4 pili (T4P) are extracellular polymers that initiate the formation of microcolonies and biofilms. T4P continuously elongate and retract. These pilus dynamics crucially affects the local order, shape, and fluidity of microcolonies. The major pilin subunit of the T4P bears multiple post-translational modifications. By interfering with different steps of the pilin glycosylation and phosphoform modification pathways, we investigated the effect of pilin post-translational modification on the shape and dynamics of microcolonies formed by Neisseria gonorrhoeae. Deleting the phosphotransferase responsible for phosphoethanolamine modification at residue serine 68 (S68) inhibits shape relaxations of microcolonies after pertubation and causes bacteria carrying the phosphoform modification to segregate to the surface of mixed colonies. We relate these mesoscopic phenotypes to increased attractive forces generated by T4P between cells. Moreover, by deleting genes responsible for the pilin glycan structure, we show that the number of saccharides attached at residue serine 63 (S63) affect the ratio between surface tension and viscosity and cause sorting between bacteria carrying different pilin glycoforms. We conclude that different pilin post-translational modifications moderately affect the attractive forces between bacteria but have severe effects on the materials properties of microcolonies.

scholarly journals Archaeal flagellin combines a bacterial type IV pilin domain with an Ig-like domain

2016 ◽  
Vol 113 (37) ◽  
pp. 10352-10357 ◽  
Author(s):  
Tatjana Braun ◽  
Matthijn R. Vos ◽  
Nir Kalisman ◽  
Nicholas E. Sherman ◽  
Reinhard Rachel ◽  
...  
Keyword(s):  
Flagellar Apparatus ◽  
Model System ◽  
Terminal Domain ◽  
Type Iv ◽  
Single Protein ◽  
Type Iv Pilin ◽  
Flagellar Filament ◽  
Ignicoccus Hospitalis ◽  
Filament Protein ◽  
Bacterial Type

The bacterial flagellar apparatus, which involves ∼40 different proteins, has been a model system for understanding motility and chemotaxis. The bacterial flagellar filament, largely composed of a single protein, flagellin, has been a model for understanding protein assembly. This system has no homology to the eukaryotic flagellum, in which the filament alone, composed of a microtubule-based axoneme, contains more than 400 different proteins. The archaeal flagellar system is simpler still, in some cases having ∼13 different proteins with a single flagellar filament protein. The archaeal flagellar system has no homology to the bacterial one and must have arisen by convergent evolution. However, it has been understood that the N-terminal domain of the archaeal flagellin is a homolog of the N-terminal domain of bacterial type IV pilin, showing once again how proteins can be repurposed in evolution for different functions. Using cryo-EM, we have been able to generate a nearly complete atomic model for a flagellar-like filament of the archaeon Ignicoccus hospitalis from a reconstruction at ∼4-Å resolution. We can now show that the archaeal flagellar filament contains a β-sandwich, previously seen in the FlaF protein that forms the anchor for the archaeal flagellar filament. In contrast to the bacterial flagellar filament, where the outer globular domains make no contact with each other and are not necessary for either assembly or motility, the archaeal flagellin outer domains make extensive contacts with each other that largely determine the interesting mechanical properties of these filaments, allowing these filaments to flex.

scholarly journals A Type IV Pilin, PilA, Contributes to Adherence of Burkholderia pseudomallei and Virulence In Vivo

2005 ◽  
Vol 73 (2) ◽  
pp. 1260-1264 ◽  
Author(s):  
Angela E. Essex-Lopresti ◽  
Justin A. Boddey ◽  
Richard Thomas ◽  
Martin P. Smith ◽  
M. Gill Hartley ◽  
...  
Keyword(s):  
Murine Model ◽  
Burkholderia Pseudomallei ◽  
Deletion Mutant ◽  
Type Iv Pili ◽  
Structural Protein ◽  
Type Iv ◽  
Type Iv Pilin ◽  
Reduced Adherence ◽  
Multiple Type

ABSTRACT The Burkholderia pseudomallei K96243 genome contains multiple type IV pilin-associated loci, including one encoding a putative pilus structural protein (pilA). A pilA deletion mutant has reduced adherence to human epithelial cells and is less virulent in the nematode model of virulence and the murine model of melioidosis, suggesting a role for type IV pili in B. pseudomallei virulence.

scholarly journals A new twist on bacterial motility – two distinct type IV pili revealed by cryoEM

2019 ◽  
Author(s):  
Alexander Neuhaus ◽  
Muniyandi Selvaraj ◽  
Ralf Salzer ◽  
Julian D. Langer ◽  
Kerstin Kruse ◽  
...  
Keyword(s):  
Natural Transformation ◽  
Thermus Thermophilus ◽  
Distinct Type ◽  
Type Iv Pili ◽  
Dna Uptake ◽  
Molecular Architecture ◽  
Surface Adhesion ◽  
Cellular Functions ◽  
Type Iv ◽  
New Type

SummaryMany bacteria express flexible protein filaments on their surface that enable a variety of important cellular functions. Type IV pili are examples of such filaments and are comprised of a helical assembly of repeating pilin subunits. Type IV pili are involved in motility (twitching), surface adhesion, biofilm formation and DNA uptake (natural transformation). They are therefore powerful structures that enable bacterial proliferation and genetic adaptation, potentially leading to the development of pathogenicity and antibiotic resistance. They are also targets for drug development.By a complement of experimental approaches, we show that the bacterium Thermus thermophilus produces two different forms of type IV pilus. We have determined the structures of both and built atomic models. The structures answer key unresolved questions regarding the molecular architecture of type IV pili and identify a new type of pilin. We also delineate the roles of the two filaments in promoting twitching and natural transformation.

scholarly journals PpdD Type IV Pilin of Escherichia coliK-12 Can Be Assembled into Pili in Pseudomonas aeruginosa

2000 ◽  
Vol 182 (3) ◽  
pp. 848-854 ◽  
Author(s):  
Nathalie Sauvonnet ◽  
Pierre Gounon ◽  
Anthony P. Pugsley
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Type Iv Pili ◽  
E Coli ◽  
Reverse Transcription Pcr ◽  
Type Iv ◽  
Type Iv Pilin ◽  
Low Levels ◽  
Fusion Analysis ◽  
K 12 ◽  
Pilin Gene

ABSTRACT Escherichia coli K-12 possesses at least 16 chromosomal genes related to genes involved in the formation of type IV pili in other gram-negative bacteria. However, E. coli K-12 does not produce type IV pili when grown under standard laboratory conditions. The results of reverse transcription-PCR, operon fusion analysis, and immunoblotting demonstrated that several of the putativeE. coli piliation genes are expressed at very low levels. Increasing the level of expression of the major pilin gene (ppdD) and the linked assembly genes hofB andhofC (homologues of the Pseudomonas aeruginosatype IV pilus assembly genes pilB and pilC) did not lead to pilus production. However, expression of theppdD gene in P. aeruginosa led to assembly of PpdD into pili that were recognized by antibodies directed against the PpdD protein. Assembly of PpdD into pili in P. aeruginosawas dependent on the expression of the pilB andpilC genes and independent of expression of the P. aeruginosa pilin structural gene pilA.

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