scholarly journals A unique genomic island-governed cannibalism in Bacillus enhanced biofilm formation through a novel regulation mechanism

2021 ◽  
Author(s):  
Rong Huang ◽  
Qing Li ◽  
Dandan Wang ◽  
Haichao Feng ◽  
Nan Zhang ◽  
...  
Keyword(s):  
Abc Transporter ◽  
Biofilm Formation ◽  
Response Regulator ◽  
Biological Significance ◽  
Signal Transduction Pathway ◽  
Phosphoryl Group ◽  
Regulation Mechanism ◽  
Two Component System ◽  
Differentiation Strategy ◽  
Bacterial Competition

Cannibalism is a differentiation strategy and social multicellular behavior in biofilms. The novel factors and mechanisms to trigger the bacterial cannibalism remain scarce. Here, we report a novel bacillunoic acids-mediated strategy for manipulating cannibalism in Bacillus velezensis SQR9 biofilm formation. A subfraction of cells differentiate into cannibals that secrete toxic bacillunoic acids to lyse a fraction of their sensitive siblings, and the released nutrients enhance biofilm formation. Meanwhile, the self-immunity of cannibal cells was induced by bacillunoic acids. A two-component system, the OmpS-OmpR signal-transduction pathway, controls the expression of the ABC transporter BnaAB for self-immunity. Specifically, bacillunoic acids activate the autophosphorylation of OmpS, a transmembrane histidine kinase, which then transfers a phosphoryl group to its response regulator OmpR. The phosphorylation of OmpR activates the transcription of the transporter gene bnaAB by binding its promoter. Thus, bacillunoic acids are pumped out of cells by the ABC transporter BnaAB. Moreover, we discovered that strain SQR9 could use the bacillunoic acids-mediated cannibalism to optimize its community to produce more bacillunoic acids for bacterial competition. This study revealed that bacillunoic acids play a previously undiscovered dual role in both cannibalism during biofilm formation and interspecies competition, which has an important biological significance.

scholarly journals Effect of Overexpressing rsmA from Pseudomonas aeruginosa on Virulence of Select Phytotoxin-Producing Strains of P. syringae

2012 ◽  
Vol 102 (6) ◽  
pp. 575-587 ◽  
Author(s):  
Hye Suk Kong ◽  
Daniel P. Roberts ◽  
Cheryl D. Patterson ◽  
Sarah A. Kuehne ◽  
Stephan Heeb ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Signal Transduction Pathway ◽  
Leaf Tissue ◽  
Transcriptional Regulators ◽  
Growth Conditions ◽  
Transduction Pathway ◽  
Two Component System ◽  
Empty Vector ◽  
Alginate Production ◽  
Two Component

The GacS/GacA two-component system functions mechanistically in conjunction with global post-transcriptional regulators of the RsmA family to allow pseudomonads and other bacteria to adapt to changing environmental stimuli. Analysis of this Gac/Rsm signal transduction pathway in phytotoxin-producing pathovars of Pseudmonas syringae is incomplete, particularly with regard to rsmA. Our approach in studying it was to overexpress rsmA in P. syringae strains through introduction of pSK61, a plasmid constitutively expressing this gene. Disease and colonization of plant leaf tissue were consistently diminished in all P. syringae strains tested (pv. phaseolicola NPS3121, pv. syringae B728a, and BR2R) when harboring pSK61 relative to these isolates harboring the empty vector pME6031. Phaseolotoxin, syringomycin, and tabtoxin were not produced in any of these strains when transformed with pSK61. Production of protease and pyoverdin as well as swarming were also diminished in all of these strains when harboring pSK61. In contrast, alginate production, biofilm formation, and the hypersensitive response were diminished in some but not all of these isolates under the same growth conditions. These results indicate that rsmA is consistently important in the overarching phenotypes disease and endophtyic colonization but that its role varies with pathovar in certain underpinning phenotypes in the phytotoxin-producing strains of P. syringae.

scholarly journals The Evanescent GacS Signal

2020 ◽  
Vol 8 (11) ◽  
pp. 1746
Author(s):  
Xavier Latour
Keyword(s):  
Biofilm Formation ◽  
Plant Protection ◽  
Signal Transduction Pathway ◽  
Low Molecular Weight ◽  
Transduction Pathway ◽  
Significant Progress ◽  
Two Component System ◽  
Wide Range ◽  
Two Component ◽  
Bacterial Fitness

The GacS histidine kinase is the membrane sensor of the major upstream two-component system of the regulatory Gac/Rsm signal transduction pathway. This pathway governs the expression of a wide range of genes in pseudomonads and controls bacterial fitness and motility, tolerance to stress, biofilm formation, and virulence or plant protection. Despite the importance of these roles, the ligands binding to the sensor domain of GacS remain unknown, and their identification is an exciting challenge in this domain. At high population densities, the GacS signal triggers a switch from primary to secondary metabolism and a change in bacterial lifestyle. It has been suggested, based on these observations, that the GacS signal is a marker of the emergence of nutritional stress and competition. Biochemical investigations have yet to characterize the GacS signal fully. However, they portray this cue as a low-molecular weight, relatively simple and moderately apolar metabolite possibly resembling, but nevertheless different, from the aliphatic organic acids acting as quorum-sensing signaling molecules in other Proteobacteria. Significant progress in the development of metabolomic tools and new databases dedicated to Pseudomonas metabolism should help to unlock some of the last remaining secrets of GacS induction, making it possible to control the Gac/Rsm pathway.

scholarly journals Cross Talk between Chemosensory Pathways That Modulate Chemotaxis and Biofilm Formation

mBio ◽  
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhou Huang ◽  
Yun-Hao Wang ◽  
Hai-Zhen Zhu ◽  
Ekaterina P. Andrianova ◽  
Cheng-Ying Jiang ◽  
...  
Keyword(s):  
Gene Regulation ◽  
Cross Talk ◽  
Biofilm Formation ◽  
Cell Cycle Progression ◽  
Developmental Process ◽  
Response Regulator ◽  
Phosphoryl Group ◽  
Comamonas Testosteroni ◽  
Content Type ◽  
Chemosensory Pathways

ABSTRACT Complex chemosensory systems control multiple biological functions in bacteria, such as chemotaxis, gene regulation, and cell cycle progression. Many species contain more than one chemosensory system per genome, but little is known about their potential interplay. In this study, we reveal cross talk between two chemosensory pathways that modulate chemotaxis and biofilm formation in Comamonas testosteroni. We demonstrate that some chemoreceptors that govern chemotaxis also contribute to biofilm formation and these chemoreceptors can physically interact with components of both pathways. Finally, we show that the chemotaxis histidine kinase CheA can phosphorylate not only its cognate response regulator CheY2 but also one of the response regulators from the pathway mediating biofilm formation, FlmD. The phosphoryl group transfer from CheA to CheY2 is much faster than that from CheA to FlmD, which is consistent with chemotaxis being a fast response and biofilm formation being a much slower developmental process. We propose that cross talk between chemosensory pathways may play a role in coordination of complex behaviors in bacteria. IMPORTANCE In many bacteria, two or more homologous chemosensory pathways control several cellular functions, such as motility and gene regulation, in response to changes in the cell’s microenvironment. Cross talk between signal transduction systems is poorly understood; while generally it is considered to be undesired, in some instances it might be beneficial for coregulation of complex behaviors. We demonstrate that several receptors from the pathway controlling motility can physically interact with downstream components of the pathway controlling biofilm formation. We further show that a kinase from the pathway controlling motility can also phosphorylate a response regulator from the pathway controlling biofilm formation. We propose that cross talk between two chemosensory pathways might be involved in coordination of two types of cell behavior—chemotaxis and biofilm formation.

scholarly journals Regulation of Galactose Metabolism through the HisK:GalR Two-Component System in Thermoanaerobacter tengcongensis

2010 ◽  
Vol 192 (17) ◽  
pp. 4311-4316 ◽  
Author(s):  
Zhong Qian ◽  
Quanhui Wang ◽  
Wei Tong ◽  
Chuanqi Zhou ◽  
Qian Wang ◽  
...  
Keyword(s):  
Phosphoryl Group ◽  
Regulation Mechanism ◽  
Two Component System ◽  
Galactose Metabolism ◽  
Component System ◽  
Two Dimensional Electrophoresis ◽  
Thermoanaerobacter Tengcongensis ◽  
Two Component ◽  
Dimensional Electrophoresis

ABSTRACT Thermoanaerobacter tengcongensis could utilize galactose as a carbon source via the enzymes encoded by a novel gal operon, whose regulation mechanism has yet to be elucidated. We propose here that the gal operon in T. tengcongensis is regulated through a HisK:GalR two-component system. By using radioactive isotope assay and genetic analysis, we found that the kinase of this system, HisK, is phosphorylated by ATP, and the regulator, GalR, accepts a phosphoryl group during phosphorelay, in which the phosphoryl group at HisK-His-259 is transferred to GalR-Asp-56. Two-dimensional electrophoresis, followed by Western blotting, revealed that phosphorylation status of GalR is uniquely dependent on the galactose stimulus in vivo. Furthermore, DNA pulldown assays demonstrated that the phosphorylated GalR prefers binding to the operator DNA O2 , whereas the unphosphorylated GalR to O1 . A model of HisK:GalR is proposed to explain how galactose mediates the expression of the gal operon in T. tengcongensis.

scholarly journals Structures of full-length VanR from Streptomyces coelicolor in both the inactive and activated states

2021 ◽  
Vol 77 (8) ◽  
Author(s):  
Lina J. Maciunas ◽  
Nadia Porter ◽  
Paula J. Lee ◽  
Kushol Gupta ◽  
Patrick J. Loll
Keyword(s):  
Resistance Genes ◽  
Bacterial Infections ◽  
Analytical Ultracentrifugation ◽  
Response Regulator ◽  
Streptomyces Coelicolor ◽  
Full Length ◽  
Phosphoryl Group ◽  
Two Component System ◽  
Receiver Domain ◽  
Serious Bacterial Infections

Vancomycin has historically been used as a last-resort treatment for serious bacterial infections. However, vancomycin resistance has become widespread in certain pathogens, presenting a serious threat to public health. Resistance to vancomycin is conferred by a suite of resistance genes, the expression of which is controlled by the VanR–VanS two-component system. VanR is the response regulator in this system; in the presence of vancomycin, VanR accepts a phosphoryl group from VanS, thereby activating VanR as a transcription factor and inducing expression of the resistance genes. This paper presents the X-ray crystal structures of full-length VanR from Streptomyces coelicolor in both the inactive and activated states at resolutions of 2.3 and 2.0 Å, respectively. Comparison of the two structures illustrates that phosphorylation of VanR is accompanied by a disorder-to-order transition of helix 4, which lies within the receiver domain of the protein. This transition generates an interface that promotes dimerization of the receiver domain; dimerization in solution was verified using analytical ultracentrifugation. The inactive conformation of the protein does not appear intrinsically unable to bind DNA; rather, it is proposed that in the activated form DNA binding is enhanced by an avidity effect contributed by the receiver-domain dimerization.

scholarly journals Diversity of two-component systems: insights into the signal transduction mechanism by the Staphylococcus aureus two-component system GraSR

F1000Research ◽  
2014 ◽  
Vol 3 ◽  
pp. 252 ◽  
Author(s):  
Uzma Muzamal ◽  
Daniel Gomez ◽  
Fenika Kapadia ◽  
Dasantila Golemi-Kotra
Keyword(s):  
Signal Transduction ◽  
Staphylococcus Aureus ◽  
Abc Transporter ◽  
Histidine Kinase ◽  
Response Regulator ◽  
Two Component System ◽  
Component System ◽  
Transduction Mechanism ◽  
Two Component ◽  
Auxiliary Protein

The response to cationic antimicrobial peptides (CAMPs) in Staphylococcus aureus relies on a two-component system (TCS), GraSR, an auxiliary protein GraX and an ATP-binding cassette (ABC) transporter, VraF/G. To understand the signal transduction mechanism by GraSR, we investigated the kinase activity of the cytoplasmic domain of histidine kinase GraS and the interaction with its cognate response regulator GraR. We also investigated interactions among the auxiliary protein GraX, GraS/R and the ATPase protein of the ABC transporter, VraF. We found that GraS lacks autophosphorylation activity, unlike a similar histidine kinase, BceS, of Bacillus subtilis. In addition, the interaction between GraS and GraR is very weak in comparison to the stronger interaction observed between BceS and its conjugated response regulator, BceR, suggesting that CAMP signaling may not flow directly from GraS to GraR. We found that the auxiliary protein GraX interacts with VraF and GraR, and requires the histidine phosphotransfer and dimerization domain of GraS to interact with this protein. Further, VraF requires the GraS region that connects the membrane-bound domain with the cytoplasmic domain of this protein for interaction with GraS. The interactions of GraX with GraS/R and VraF indicate that GraX may serve as a scaffold to bring these proteins in close proximity to GraS, plausibly to facilitate activation of GraS to ultimately transduce the signal to GraR.

scholarly journals A Two-Component System Regulates the Expression of an ABC Transporter for Xylo-Oligosaccharides in Geobacillus stearothermophilus

2006 ◽  
Vol 73 (3) ◽  
pp. 874-884 ◽  
Author(s):  
Smadar Shulami ◽  
Galia Zaide ◽  
Gennady Zolotnitsky ◽  
Yael Langut ◽  
Geoff Feld ◽  
...  
Keyword(s):  
Abc Transporter ◽  
Transport System ◽  
Response Regulator ◽  
Transcriptional Unit ◽  
Geobacillus Stearothermophilus ◽  
Two Component System ◽  
Component System ◽  
Abc Transport ◽  
Two Component

ABSTRACT Geobacillus stearothermophilus T-6 utilizes an extensive and highly regulated hemicellulolytic system. The genes comprising the xylanolytic system are clustered in a 39.7-kb chromosomal segment. This segment contains a 6-kb transcriptional unit (xynDCEFG) coding for a potential two-component system (xynDC) and an ATP-binding cassette (ABC) transport system (xynEFG). The xynD promoter region contains a 16-bp inverted repeat resembling the operator site for the xylose repressor, XylR. XylR was found to bind specifically to this sequence, and binding was efficiently prevented in vitro in the presence of xylose. The ABC transport system was shown to comprise an operon of three genes (xynEFG) that is transcribed from its own promoter. The nonphosphorylated fused response regulator, His6-XynC, bound to a 220-bp fragment corresponding to the xynE operator. DNase I footprinting analysis showed four protected zones that cover the −53 and the +34 regions and revealed direct repeat sequences of a GAAA-like motif. In vitro transcriptional assays and quantitative reverse transcription-PCR demonstrated that xynE transcription is activated 140-fold in the presence of 1.5 μM XynC. The His6-tagged sugar-binding lipoprotein (XynE) of the ABC transporter interacted with different xylosaccharides, as demonstrated by isothermal titration calorimetry. The change in the heat capacity of binding (ΔC p) for XynE with xylotriose suggests a stacking interaction in the binding site that can be provided by a single Trp residue and a sugar moiety. Taken together, our data show that XynEFG constitutes an ABC transport system for xylo-oligosaccharides and that its transcription is negatively regulated by XylR and activated by the response regulator XynC, which is part of a two-component sensing system.

scholarly journals Phosphorelay as the Sole Physiological Route of Signal Transmission by the Arc Two-Component System ofEscherichia coli

2000 ◽  
Vol 182 (13) ◽  
pp. 3858-3862 ◽  
Author(s):  
Ohsuk Kwon ◽  
Dimitris Georgellis ◽  
E. C. C. Lin
Keyword(s):  
Response Regulator ◽  
Signal Transmission ◽  
Phosphoryl Group ◽  
Sensor Kinase ◽  
Wild Type ◽  
Two Component System ◽  
Component System ◽  
Group Transfer ◽  
Two Component

ABSTRACT The Arc two-component system, comprising a tripartite sensor kinase (ArcB) and a response regulator (ArcA), modulates the expression of numerous genes involved in respiratory functions. In this study, the steps of phosphoryl group transfer from phosphorylated ArcB to ArcA were examined in vivo by using single copies of wild-type and mutantarcB alleles. The results indicate that the signal transmission occurs solely by His-Asp-His-Asp phosphorelay.

scholarly journals Intra- and intermolecular domain interactions among novel two-component system proteins coded by Rv0600c, Rv0601c and Rv0602c of Mycobacterium tuberculosis

Microbiology ◽  
2009 ◽  
Vol 155 (3) ◽  
pp. 772-779 ◽  
Author(s):  
Rashmi Shrivastava ◽  
Ananta Kumar Ghosh ◽  
Amit Kumar Das
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Histidine Kinase ◽  
Response Regulator ◽  
Dominant Role ◽  
Phosphoryl Group ◽  
Two Component System ◽  
Component System ◽  
Two Component ◽  
Domain Interactions ◽  
Cognate Response Regulator

Two-component signal transduction pathways comprising a histidine kinase and its cognate response regulator play a dominant role in the adaptation of Mycobacterium tuberculosis to its host, and its virulence, pathogenicity and latency. Autophosphorylation occurs at a conserved histidine of the histidine kinase and subsequently the phosphoryl group is transferred to the conserved aspartate of its cognate response regulator. Among the twelve two-component systems of M. tuberculosis, Rv0600c (HK1), Rv0601c (HK2) and Rv0602c (TcrA) are annotated as a unique three-protein two-component system. HK1 contains an ATP-binding domain, and HK2, a novel Hpt mono-domain protein, contains the conserved phosphorylable histidine residue. HK1 and HK2 complement each other's functions. Interactions among different domains of the HK1, HK2 and TcrA proteins were studied using a yeast two-hybrid system. Self-interaction was observed for HK2 but not for HK1 or TcrA. HK2 was found to interact reasonably well with both HK1 and TcrA, but HK1 interacted weakly with TcrA. The conserved aspartate-containing receiver domain of TcrA interacted well with HK2 but not with HK1. These results suggest the existence of a novel signalling mechanism amongst HK1–HK2–TcrA, and a model for this mechanism is proposed.

scholarly journals Diversity of two-component systems: insights into the signal transduction mechanism by the Staphylococcus aureus two-component system GraSR

F1000Research ◽  
2014 ◽  
Vol 3 ◽  
pp. 252 ◽  
Author(s):  
Uzma Muzamal ◽  
Daniel Gomez ◽  
Fenika Kapadia ◽  
Dasantila Golemi-Kotra
Keyword(s):  
Signal Transduction ◽  
Staphylococcus Aureus ◽  
Abc Transporter ◽  
Histidine Kinase ◽  
Response Regulator ◽  
Two Component System ◽  
Component System ◽  
Transduction Mechanism ◽  
Two Component ◽  
Auxiliary Protein

The response to cationic antimicrobial peptides (CAMPs) in Staphylococcus aureus relies on a two-component system (TCS), GraSR, an auxiliary protein GraX and an ATP-binding cassette (ABC) transporter, VraF/G. To understand the signal transduction mechanism by GraSR, we investigated the kinase activity of the cytoplasmic domain of histidine kinase GraS and the interaction with its cognate response regulator GraR. We also investigated interactions among the auxiliary protein GraX, GraS/R and the ATPase protein of the ABC transporter, VraF. We found that GraS lacks autophosphorylation activity, unlike a similar histidine kinase, BceS, of Bacillus subtilis. In addition, the interaction between GraS and GraR is very weak in comparison to the stronger interaction observed between BceS and its conjugated response regulator, BceR, suggesting that CAMP signaling may not flow directly from GraS to GraR. We found that the auxiliary protein GraX interacts with VraF and GraR, and requires the histidine phosphotransfer and dimerization domain of GraS to interact with this protein. Further, VraF requires the GraS region that connects the membrane-bound domain with the cytoplasmic domain of this protein for interaction with GraS. The interactions of GraX with GraS/R and VraF indicate that GraX may serve as a scaffold to bring these proteins in close proximity to GraS, plausibly to facilitate activation of GraS to ultimately transduce the signal to GraR.

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