scholarly journals Lysobacter PilR, the Regulator of Type IV Pilus Synthesis, Controls Antifungal Antibiotic Production via a Cyclic di-GMP Pathway

2017 ◽  
Vol 83 (7) ◽  
Author(s):  
Yuan Chen ◽  
Jing Xia ◽  
Zhenhe Su ◽  
Gaoge Xu ◽  
Mark Gomelsky ◽  
...  
Keyword(s):  
Response Regulator ◽  
Antibiotic Production ◽  
Second Messenger ◽  
Twitching Motility ◽  
Type Iv Pilus ◽  
Content Type ◽  
Lysobacter Enzymogenes ◽  
Antifungal Antibiotic ◽  
Type Iv ◽  
Two Component

ABSTRACT Lysobacter enzymogenes is a ubiquitous soil gammaproteobacterium that produces a broad-spectrum antifungal antibiotic, known as heat-stable antifungal factor (HSAF). To increase HSAF production for use against fungal crop diseases, it is important to understand how HSAF synthesis is regulated. To gain insights into transcriptional regulation of the HSAF synthesis gene cluster, we generated a library with deletion mutations in the genes predicted to encode response regulators of the two-component signaling systems in L. enzymogenes strain OH11. By quantifying HSAF production levels in the 45 constructed mutants, we identified two strains that produced significantly smaller amounts of HSAF. One of the mutations affected a gene encoding a conserved bacterial response regulator, PilR, which is commonly associated with type IV pilus synthesis. We determined that L. enzymogenes PilR regulates pilus synthesis and twitching motility via a traditional pathway, by binding to the pilA promoter and upregulating pilA expression. Regulation of HSAF production by PilR was found to be independent of pilus formation. We discovered that the pilR mutant contained significantly higher intracellular levels of the second messenger cyclic di-GMP (c-di-GMP) and that this was the inhibitory signal for HSAF production. Therefore, the type IV pilus regulator PilR in L. enzymogenes activates twitching motility while downregulating antibiotic HSAF production by increasing intracellular c-di-GMP levels. This study identifies a new role of a common pilus regulator in proteobacteria and provides guidance for increasing antifungal antibiotic production in L. enzymogenes. IMPORTANCE PilR is a widespread response regulator of the two-component system known for regulating type IV pilus synthesis in proteobacteria. Here we report that, in the soil bacterium Lysobacter enzymogenes, PilR regulates pilus synthesis and twitching motility, as expected. Unexpectedly, PilR was also found to control intracellular levels of the second messenger c-di-GMP, which in turn inhibits production of the antifungal antibiotic HSAF. The coordinated production of type IV pili and antifungal antibiotics has not been observed previously.

Two direct gene targets contribute to Clp-dependent regulation of type IV pilus-mediated twitching motility in Lysobacter enzymogenes OH11

2018 ◽  
Vol 102 (17) ◽  
pp. 7509-7519 ◽  
Author(s):  
Jiaojiao Chen ◽  
Danyu Shen ◽  
Benard Omondi Odhiambo ◽  
Dan Xu ◽  
Sen Han ◽  
...  
Keyword(s):  
Twitching Motility ◽  
Type Iv Pilus ◽  
Lysobacter Enzymogenes ◽  
Type Iv ◽  
Direct Gene

scholarly journals Coordinated control of the type IV pili and c‐di‐GMP‐dependent antifungal antibiotic production in L ysobacter by the response regulator PilR

2021 ◽  
Vol 22 (5) ◽  
pp. 602-617
Author(s):  
Kangwen Xu ◽  
Danyu Shen ◽  
Nianda Yang ◽  
Shan‐Ho Chou ◽  
Mark Gomelsky ◽  
...  
Keyword(s):  
Response Regulator ◽  
Antibiotic Production ◽  
Coordinated Control ◽  
Type Iv Pili ◽  
Antifungal Antibiotic ◽  
Type Iv

scholarly journals ThePseudomonas aeruginosaPilSR Two-Component System Regulates Both Twitching and Swimming Motilities

mBio ◽  
2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Sara L. N. Kilmury ◽  
Lori L. Burrows
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Type Iv Pili ◽  
Geobacter Sulfurreducens ◽  
Type Iv Pilus ◽  
Two Component System ◽  
Component System ◽  
Content Type ◽  
Swimming Motility ◽  
Type Iv ◽  
Two Component

ABSTRACTMotility is an important virulence trait for many bacterial pathogens, allowing them to position themselves in appropriate locations at appropriate times. The motility structures type IV pili and flagella are also involved in sensing surface contact, which modulates pathogenicity. InPseudomonas 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 ofGeobacter sulfurreducensandDichelobacter nodosusimplicated PilR in regulation of non-T4P-related genes, including some involved in flagellar biosynthesis. Here we used transcriptome sequencing (RNA-seq) analysis to identify genes in addition topilAwith changes in expression in the absence ofpilR. Among the genes identified were 10 genes whose transcription increased in thepilAmutant but decreased in thepilRmutant, despite both mutants lacking T4P and pilus-related phenotypes. The products of these inversely dysregulated genes, many of which were hypothetical, may be important for virulence and surface-associated behaviors, as mutants had altered swarming motility, biofilm formation, type VI secretion system expression, and pathogenicity in a nematode model. Further, the PilSR TCS positively regulated transcription offleSR, and thus many genes in the FleSR regulon. As a result,pilSRdeletion 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 could have a broader role in the regulation ofP. aeruginosamotility and surface sensing behaviors.IMPORTANCESurface appendages such as type IV pili and flagella are important for establishing surface attachment and infection in a host in response to appropriate cues. The PilSR regulatory system that controls type IV pilus expression inPseudomonas aeruginosahas an established role in expression of the major pilin PilA. Here we provide evidence supporting a new role for PilSR in regulating flagellum-dependent swimming motility in addition to pilus-dependent twitching motility. Further, even though bothpilAandpilRmutants lack PilA and pili, we identified sets of genes downregulated in thepilRmutant and upregulated in apilAmutant as well as genes downregulated only in apilRmutant, independent of pilus expression. This finding suggests that change in the inner membrane levels of PilA is only one of the cues to which PilR responds to modulate gene expression. Identification of PilR as a regulator of multiple motility pathways may make it an interesting therapeutic target for antivirulence compounds.

scholarly journals Indole-Induced Reversion of Intrinsic Multiantibiotic Resistance in Lysobacter enzymogenes

2017 ◽  
Vol 83 (17) ◽  
Author(s):  
Yong Han ◽  
Yan Wang ◽  
Yameng Yu ◽  
Haotong Chen ◽  
Yuemao Shen ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antibiotic Susceptibility ◽  
Response Regulator ◽  
Resistant Bacterium ◽  
Intrinsic Resistance ◽  
Content Type ◽  
Membrane Sensor ◽  
Lysobacter Enzymogenes ◽  
Two Component ◽  
Indole Production

ABSTRACT Lysobacter species are a group of environmental bacteria that are emerging as a new source of antibiotics. One characteristic of Lysobacter is intrinsic resistance to multiple antibiotics, which had not been studied. To understand the resistance mechanism, we tested the effect of blocking two-component regulatory systems (TCSs) on the antibiotic resistance of Lysobacter enzymogenes, a prolific producer of antibiotics. Upon treatment with LED209, an inhibitor of the widespread TCS QseC/QseB, L. enzymogenes produced a large amount of an unknown metabolite that was barely detectable in the untreated culture. Subsequent structural elucidation by nuclear magnetic resonance (NMR) unexpectedly revealed that the metabolite was indole. Indole production was also markedly induced by adrenaline, a known modulator of QseC/QseB. Next, we identified two TCS genes, L. enzymogenes qseC (Le-qseC) and Le-qseB, in L. enzymogenes and found that mutations of Le-qseC and Le-qseB also led to a dramatic increase in indole production. We then chemically synthesized a fluorescent indole probe that could label the cells. While the Le-qseB (cytoplasmic response regulator) mutant was clearly labeled by the probe, the Le-qseC (membrane sensor) mutant was not labeled. It was reported previously that indole can enhance antibiotic resistance in bacteria. Therefore, we tested if the dramatic increase in the level of indole production in L. enzymogenes upon blocking of Le-qseC and Le-qseB would lead to enhanced antibiotic resistance. Surprisingly, we found that indole caused the intrinsically multiantibiotic-resistant bacterium L. enzymogenes to become susceptible. Point mutations at conserved amino acids in Le-QseC also led to antibiotic susceptibility. Because indole is known as an interspecies signal, these findings may have implications. IMPORTANCE The environmental bacterium Lysobacter is a new source of antibiotic compounds and exhibits intrinsic antibiotic resistance. Here, we found that the inactivation of a two-component regulatory system (TCS) by an inhibitor or by gene deletion led to a remarkable increase in the level of production of a metabolite in L. enzymogenes, and this metabolite was identified to be indole. We chemically synthesized a fluorescent indole probe and found that it could label the wild type and a mutant of the TCS cytoplasmic response regulator but not a mutant of the TCS membrane sensor. Indole treatment caused the intrinsically multidrug-resistant bacterium L. enzymogenes to be susceptible to antibiotics. Mutations of the TCS sensor also led to antibiotic susceptibility. Because indole is known as an interspecies signal between gut microbiota and mammalian hosts, the observation that indole could render intrinsically resistant L. enzymogenes susceptible to common antibiotics may have implications.

scholarly journals Type IV Pilus Biogenesis, Twitching Motility, and DNA Uptake in Thermus thermophilus: Discrete Roles of Antagonistic ATPases PilF, PilT1, and PilT2

2013 ◽  
Vol 80 (2) ◽  
pp. 644-652 ◽  
Author(s):  
Ralf Salzer ◽  
Friederike Joos ◽  
Beate Averhoff
Keyword(s):  
Natural Transformation ◽  
Thermophilic Bacteria ◽  
Bacterial Species ◽  
Thermus Thermophilus ◽  
Dna Uptake ◽  
Twitching Motility ◽  
Type Iv Pilus ◽  
Content Type ◽  
Ecological Diversification ◽  
Type Iv

ABSTRACTNatural transformation has a large impact on lateral gene flow and has contributed significantly to the ecological diversification and adaptation of bacterial species.Thermus thermophilusHB27 has emerged as the leading model organism for studies of DNA transporters in thermophilic bacteria. Recently, we identified a zinc-binding polymerization nucleoside triphosphatase (NTPase), PilF, which is essential for the transport of DNA through the outer membrane. Here, we present genetic evidence that PilF is also essential for the biogenesis of pili. One of the most challenging questions was whetherT. thermophilushas any depolymerization NTPase acting as a counterplayer of PilF. We identified two depolymerization NTPases, PilT1 (TTC1621) and PilT2 (TTC1415), both of which are required for type IV pilus (T4P)-mediated twitching motility and adhesion but dispensable for natural transformation. This suggests that T4P dynamics are not required for natural transformation. The latter finding is consistent with our suggestion that inT. thermophilus, T4P and natural transformation are linked but distinct systems.

scholarly journals Pseudomonas aeruginosa AlgR Regulates Type IV Pilus Biosynthesis by Activating Transcription of the fimU-pilVWXY1Y2E Operon

2008 ◽  
Vol 190 (6) ◽  
pp. 2023-2030 ◽  
Author(s):  
Belen Belete ◽  
Haiping Lu ◽  
Daniel J. Wozniak
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Response Regulator ◽  
Transcriptional Profiling ◽  
Pcr Analysis ◽  
Twitching Motility ◽  
Type Iv Pilus ◽  
Mobility Shift ◽  
Type Iv ◽  
Type Iv Pilin ◽  
Electrophoretic Mobility Shift Assays

ABSTRACT The response regulator AlgR is required for Pseudomonas aeruginosa type IV pilus-dependent twitching motility, a flagellum-independent mode of solid surface translocation. Prior work showed that AlgR is phosphorylated at aspartate 54, and cells expressing an AlgR variant that cannot undergo phosphorylation (AlgRD54N) lack twitching motility. However, the mechanism by which AlgR controls twitching motility is not completely understood. We hypothesized that AlgR functioned by activating genes within the prepilin fimU-pilVWXY1Y2E cluster that are necessary for type IV pilin biogenesis. Reverse transcriptase PCR analysis showed that the fimU-pilVWXY1Y2E genes are cotranscribed in an operon, which is under the control of AlgR. This supports prior transcriptional profiling studies of wild-type strains and algR mutants. Moreover, expression of the fimU-pilVWXY1Y2E operon was reduced in strains expressing AlgRD54N. DNase footprinting and electrophoretic mobility shift assays demonstrate that AlgR but not AlgRD54N bound with high affinity to two sites upstream of the fimU-pilVWXY1Y2E operon. Altogether, our findings indicate that AlgR is essential for proper pilin localization and that phosphorylation of AlgR results in direct activation of the fimU-pilVWXY1Y2E operon, which is required for the assembly and export of a functional type IV pilus.

scholarly journals Seminal Plasma Initiates a Neisseria gonorrhoeae Transmission State

mBio ◽  
2014 ◽  
Vol 5 (2) ◽  
Author(s):  
Mark T. Anderson ◽  
Lena Dewenter ◽  
Berenike Maier ◽  
H. Steven Seifert
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Seminal Plasma ◽  
Seminal Fluid ◽  
Sexual Transmission ◽  
Type Iv Pili ◽  
Twitching Motility ◽  
Type Iv Pilus ◽  
Content Type ◽  
Host Environment ◽  
Type Iv

ABSTRACTNiche-restricted pathogens are evolutionarily linked with the specific biological fluids that are encountered during infection.Neisseria gonorrhoeaecauses the genital infection gonorrhea and is exposed to seminal fluid during sexual transmission. Treatment ofN. gonorrhoeaewith seminal plasma or purified semen proteins lactoferrin, serum albumin, and prostate-specific antigen each facilitated type IV pilus-mediated twitching motility of the bacterium. Motility in the presence of seminal plasma was characterized by high velocity and low directional persistence. In addition, infection of epithelial cells withN. gonorrhoeaein the presence of seminal plasma resulted in enhanced microcolony formation. Close association of multiple pili in the form of bundles was also disrupted after seminal plasma treatment leading to an increase in the number of single pilus filaments on the bacterial surface. Thus, exposure ofN. gonorrhoeaeto seminal plasma is proposed to alter bacterial motility and aggregation characteristics to influence the processes of transmission and colonization.IMPORTANCEThere are greater than 100 million estimated new cases of gonorrhea annually worldwide. Research characterizing the mechanisms of pathogenesis and transmission ofNeisseria gonorrhoeaeis important for developing new prevention strategies, since antibiotic resistance of the organism is becoming increasingly prevalent. Our work identifies seminal plasma as a mediator ofN. gonorrhoeaetwitching motility and microcolony formation through functional modification of the type IV pilus. These findings provide insight into motility dynamics and epithelial cell colonization under conditions that are relevant to sexual transmission. Type IV pili are common virulence factors with diverse functions among bacterial pathogens, and this work identifies interactions between type IV pili and the host environment. Finally, this work illustrates the importance of the host environment and niche-specific fluids on microbial pathogenesis.

Identification and initial characterization of a new pair of sibling sRNAs of Neisseria gonorrhoeae involved in type IV pilus biogenesis

Microbiology ◽  
2021 ◽  
Vol 167 (9) ◽  
Author(s):  
Marie Zachary ◽  
Susanne Bauer ◽  
Maximilian Klepsch ◽  
Katharina Wagler ◽  
Bruno Hüttel ◽  
...  
Keyword(s):  
Target Genes ◽  
Target Prediction ◽  
Type Iv Pilus ◽  
Content Type ◽  
Type Iv ◽  
Gene Expression Control ◽  
Initial Characterization ◽  
Pilus Biogenesis ◽  
Regulatory Rnas

Non-coding regulatory RNAs mediate post-transcriptional gene expression control by a variety of mechanisms relying mostly on base-pairing interactions with a target mRNA. Though a plethora of putative non-coding regulatory RNAs have been identified by global transcriptome analysis, knowledge about riboregulation in the pathogenic Neisseriae is still limited. Here we report the initial characterization of a pair of sRNAs of N. gonorrhoeae , TfpR1 and TfpR2, which exhibit a similar secondary structure and identical single-stranded seed regions, and therefore might be considered as sibling sRNAs. By combination of in silico target prediction and sRNA pulse expression followed by differential RNA sequencing we identified target genes of TfpR1 which are involved in type IV pilus biogenesis and DNA damage repair. We provide evidence that members of the TfpR1 regulon can also be targeted by the sibling TfpR2.

scholarly journals Identification of a Second Two-Component Signal Transduction System That Controls Fosfomycin Tolerance and Glycerol-3-Phosphate Uptake

2014 ◽  
Vol 197 (5) ◽  
pp. 861-871 ◽  
Author(s):  
Kumiko Kurabayashi ◽  
Yuko Hirakawa ◽  
Koichi Tanimoto ◽  
Haruyoshi Tomita ◽  
Hidetada Hirakawa
Keyword(s):  
Phosphate Uptake ◽  
Response Regulator ◽  
Anaerobic Respiration ◽  
Regulatory System ◽  
Carbon Substrate ◽  
Two Component System ◽  
Component System ◽  
Content Type ◽  
Two Component ◽  
Biological Cost

Particular interest in fosfomycin has resurfaced because it is a highly beneficial antibiotic for the treatment of refractory infectious diseases caused by pathogens that are resistant to other commonly used antibiotics. The biological cost to cells of resistance to fosfomycin because of chromosomal mutation is high. We previously found that a bacterial two-component system, CpxAR, induces fosfomycin tolerance in enterohemorrhagicEscherichia coli(EHEC) O157:H7. This mechanism does not rely on irreversible genetic modification and allows EHEC to relieve the fitness burden that results from fosfomycin resistance in the absence of fosfomycin. Here we show that another two-component system, TorSRT, which was originally characterized as a regulatory system for anaerobic respiration utilizing trimethylamine-N-oxide (TMAO), also induces fosfomycin tolerance. Activation of the Tor regulatory pathway by overexpression oftorR, which encodes the response regulator, or addition of TMAO increased fosfomycin tolerance in EHEC. We also show that phosphorylated TorR directly represses the expression ofglpT, a gene that encodes a symporter of fosfomycin and glycerol-3-phosphate, and activation of the TorR protein results in the reduced uptake of fosfomycin by cells. However, cells in which the Tor pathway was activated had an impaired growth phenotype when cultured with glycerol-3-phosphate as a carbon substrate. These observations suggest that the TorSRT pathway is the second two-component system to reversibly control fosfomycin tolerance and glycerol-3-phosphate uptake in EHEC, and this may be beneficial for bacteria by alleviating the biological cost. We expect that this mechanism could be a potential target to enhance the utility of fosfomycin as chemotherapy against multidrug-resistant pathogens.

scholarly journals The role of core and accessory type IV pilus genes in natural transformation and twitching motility in the bacterium Acinetobacter baylyi

PLoS ONE ◽  
2017 ◽  
Vol 12 (8) ◽  
pp. e0182139 ◽  
Author(s):  
Colleen G. Leong ◽  
Rebecca A. Bloomfield ◽  
Caroline A. Boyd ◽  
Amber J. Dornbusch ◽  
Leah Lieber ◽  
...  
Keyword(s):  
Natural Transformation ◽  
Twitching Motility ◽  
Type Iv Pilus ◽  
Acinetobacter Baylyi ◽  
Type Iv
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