scholarly journals The Group III Two-Component Histidine Kinase of Filamentous Fungi Is Involved in the Fungicidal Activity of the Bacterial Polyketide Ambruticin

2008 ◽  
Vol 75 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Anita Dongo ◽  
Nelly Bataill�-Simoneau ◽  
Claire Campion ◽  
Thomas Guillemette ◽  
Bruno Hamon ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Histidine Kinase ◽  
Response Regulator ◽  
Alternaria Brassicicola ◽  
Mitogen Activated Protein Kinase ◽  
Natural Resistance ◽  
Single Amino Acid ◽  
Kinase Gene ◽  
Group Iii ◽  
Moderate Resistance

ABSTRACT We have shown that the plant pathogen Alternaria brassicicola exhibited very high susceptibility to ambruticin VS4 and to a lesser extent to the phenylpyrrole fungicide fludioxonil. These compounds are both derived from natural bacterial metabolites with antifungal properties and are thought to exert their toxicity by interfering with osmoregulation in filamentous fungi. Disruption of the osmosensor group III histidine kinase gene AbNIK1 (for A. brassicola NIK1) resulted in high levels of resistance to ambruticin and fludioxonil, while a mutant isolate characterized by a single-amino-acid substitution in the HAMP domain of the kinase only exhibited moderate resistance. Moreover, the natural resistance of Saccharomyces cerevisiae to these antifungal molecules switched to sensitivity in strains expressing AbNIK1p. We also showed that exposure to fludioxonil and ambruticin resulted in abnormal phosphorylation of a Hog1-like mitogen-activated protein kinase (MAPK) in A. brassicicola. Parallel experiments carried out with wild-type and mutant isolates of Neurospora crassa revealed that, in this species, ambruticin susceptibility was dependent on the OS1-RRG1 branch of the phosphorelay pathway downstream of the OS2 MAPK cascade but independent of the yeast Skn7-like response regulator RRG2. These results show that the ability to synthesize a functional group III histidine kinase is a prerequisite for the expression of ambruticin and phenylpyrrole susceptibility in A. brassicicola and N. crassa and that, at least in the latter species, improper activation of the high-osmolarity glycerol-related pathway could explain their fungicidal properties.

scholarly journals Two-Component Response Regulators Ssk1p and Skn7p Additively Regulate High-Osmolarity Adaptation and Fungicide Sensitivity in Cochliobolus heterostrophus

2006 ◽  
Vol 6 (2) ◽  
pp. 171-181 ◽  
Author(s):  
Kosuke Izumitsu ◽  
Akira Yoshimi ◽  
Chihiro Tanaka
Keyword(s):  
Histidine Kinase ◽  
Response Regulator ◽  
Mitogen Activated Protein Kinase ◽  
Cochliobolus Heterostrophus ◽  
Response Regulators ◽  
Fungicide Sensitivity ◽  
High Osmolarity ◽  
Group Iii ◽  
Two Component ◽  
Moderate Resistance

ABSTRACT Filamentous ascomycetous fungi possess many histidine kinases and two conserved response regulators, Ssk1p and Skn7p, in their two-component signaling systems. We previously reported that the fungus unique group III histidine kinase regulates high-osmolarity adaptation and iprodione/fludioxonil fungicide sensitivity by controlling the phosphorylation of Hog1-type mitogen-activated protein kinase (MAPK) in filamentous ascomycetes. Here, we have characterized the response regulator genes ChSsk1 and ChSkn7 in the southern corn leaf blight fungus Cochliobolus heterostrophus. Both ChSsk1- and ChSkn7-disrupted mutants showed little sensitivity to high-osmolarity stress and moderate resistance to the iprodione/fludioxonil fungicides. The phosphorylation of Hog1-type MAPK BmHog1p induced by high-osmolarity stress and fungicide treatments was only regulated by ChSsk1p, indicating that ChSkn7p has roles in high-osmolarity adaptation and fungicide sensitivity that are independent from the activation of BmHog1p. The Chssk1 Chskn7 double mutants clearly showed higher sensitivity to osmolar stress and higher resistance to fungicides than the single mutants. The dose responses of the double mutants fit well with those of the group III histidine kinase-deficient strain. These results suggest that in filamentous ascomycetes, the Ssk1- and Skn7-type response regulators control high-osmolarity adaptation and fungicide sensitivity additively with differential mechanisms under the regulation of the group III histidine kinase. This study provides evidence that filamentous fungi have a unique two-component signaling system that is different from that of yeast and is responsible for high-osmolarity adaptation and fungicide sensitivity.

scholarly journals Group III Histidine Kinase Is a Positive Regulator of Hog1-Type Mitogen-Activated Protein Kinase in Filamentous Fungi

2005 ◽  
Vol 4 (11) ◽  
pp. 1820-1828 ◽  
Author(s):  
Akira Yoshimi ◽  
Kaihei Kojima ◽  
Yoshitaka Takano ◽  
Chihiro Tanaka
Keyword(s):  
Osmotic Stress ◽  
Filamentous Fungi ◽  
Histidine Kinase ◽  
Type Strain ◽  
Wild Type Strain ◽  
Wild Type ◽  
Group Iii ◽  
Positive Regulator ◽  
Mitogen Activated Protein ◽  
In The Wild

ABSTRACT We previously reported that the group III histidine kinase Dic1p in the maize pathogen Cochliobolus heterostrophus is involved in resistance to dicarboximide and phenylpyrrole fungicides and in osmotic adaptation. In addition, exposure to the phenylpyrrole fungicide fludioxonil led to improper activation of Hog1-type mitogen-activated protein kinases (MAPKs) in some phytopathogenic fungi, including C. heterostrophus. Here we report, for the first time, the relationship between the group III histidine kinase and Hog1-related MAPK: group III histidine kinase is a positive regulator of Hog1-related MAPK in filamentous fungi. The phosphorylation pattern of C. heterostrophus BmHog1p (Hog1-type MAPK) was analyzed in wild-type and dic1-deficient strains by Western blotting. In the wild-type strain, phosphorylated BmHog1p was detected after exposure to both iprodione and fludioxonil at a concentration of 1 μg/ml. In the dic1-deficient strains, phosphorylated BmHog1p was not detected after exposure to 10 μg/ml of the fungicides. In response to osmotic stress (0.4 M KCl), a trace of phosphorylated BmHog1p was found in the dic1-deficient strains, whereas the band representing active BmHog1p was clearly detected in the wild-type strain. Similar results were obtained for Neurospora crassa Os-2p MAPK phosphorylation in the mutant of the group III histidine kinase gene os-1. These results indicate that group III histidine kinase positively regulates the activation of Hog1-type MAPKs in filamentous fungi. Notably, the Hog1-type MAPKs were activated at high fungicide (100 μg/ml) and osmotic stress (0.8 M KCl) levels in the histidine kinase mutants of both fungi, suggesting that another signaling pathway activates Hog1-type MAPKs in these conditions.

scholarly journals Sensor histidine kinase is a β-lactam receptor and induces resistance to β-lactam antibiotics

2016 ◽  
Vol 113 (6) ◽  
pp. 1648-1653 ◽  
Author(s):  
Lu Li ◽  
Qiyao Wang ◽  
Hui Zhang ◽  
Minjun Yang ◽  
Mazhar I. Khan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Histidine Kinase ◽  
Vibrio Parahaemolyticus ◽  
Response Regulator ◽  
Strong Support ◽  
Binding Pocket ◽  
Single Amino Acid ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Direct Recognition

β-Lactams disrupt bacterial cell wall synthesis, and these agents are the most widely used antibiotics. One of the principle mechanisms by which bacteria resist the action of β-lactams is by producing β-lactamases, enzymes that degrade β-lactams. In Gram-negative bacteria, production of β-lactamases is often induced in response to the antibiotic-associated damage to the cell wall. Here, we have identified a previously unidentified mechanism that governs β-lactamase production. In the Gram-negative enteric pathogenVibrio parahaemolyticus, we found a histidine kinase/response regulator pair (VbrK/VbrR) that controls expression of a β-lactamase. Mutants lacking either VbrK or VbrR do not produce the β-lactamase and are no longer resistant to β-lactam antibiotics. Notably, VbrK autophosphorylation is activated by β-lactam antibiotics, but not by other lactams. However, single amino acid substitutions in the putative periplasmic binding pocket of VbrK leads its phosphorylation in response to both β-lactam and other lactams, suggesting that this kinase is a β-lactam receptor that can directly detect β-lactam antibiotics instead of detecting the damage to cell wall resulting from β-lactams. In strong support of this idea, we found that purified periplasmic sensor domain of VbrK binds penicillin, and that such binding is critical for VbrK autophosphorylation and β-lactamase production. Direct recognition of β-lactam antibiotics by a histidine kinase receptor may represent an evolutionarily favorable mechanism to defend against β-lactam antibiotics.

scholarly journals Effect of new alleles of the histidine kinase gene ciaH on the activity of the response regulator CiaR in Streptococcus pneumoniae R6

Microbiology ◽  
2011 ◽  
Vol 157 (11) ◽  
pp. 3104-3112 ◽  
Author(s):  
Miriam Müller ◽  
Patrick Marx ◽  
Regine Hakenbeck ◽  
Reinhold Brückner
Keyword(s):  
Streptococcus Pneumoniae ◽  
Histidine Kinase ◽  
Response Regulator ◽  
Regulatory System ◽  
Competence Development ◽  
Kinase Gene ◽  
Lactam Antibiotic ◽  
Spontaneous Mutants ◽  
New Alleles

The two-component regulatory system CiaRH of Streptococcus pneumoniae affects β-lactam susceptibility, autolysis, bacteriocin production, competence development, host colonization and virulence. The system was discovered in a screen for S. pneumoniae R6 mutants resistant to the β-lactam antibiotic cefotaxime. A mutation in the histidine kinase gene ciaH led to this phenotype by enhancing CiaR-mediated gene expression. Additional mutations in ciaH have been described in other spontaneous β-lactam-resistant mutants of S. pneumoniae R6, but their influence on CiaR-mediated gene regulation has not been determined. Likewise, altered ciaH alleles are present in clinical S. pneumoniae isolates, none of which had been characterized. These novel ciaH variants were introduced into S. pneumoniae R6 to measure their ability to activate CiaR-dependent regulation. The ciaH alleles from spontaneous mutants obtained in the laboratory increased the activity of CiaR-dependent promoters between four- and 26-fold, while variants from clinical strains were less effective, with a threefold activation at most. Accordingly, phenotypes associated with a hyperactive CiaRH system, β-lactam resistance, and prevention of competence development, were far more pronounced in the laboratory mutants. Amino acid changes affecting CiaH function were positioned throughout the protein. Five of the most activating changes are located close to the conserved histidine and one in the extracytoplasmic sensor domain. The characterization of new alleles of ciaH expands the spectrum of CiaH variants, which may help to elucidate signal transduction of this important regulatory system. Our study also demonstrates that ciaH alleles overstimulating CiaR regulon expression are present in clinical isolates of S. pneumoniae.

scholarly journals The response regulator PhoP4 is required for late developmental events in Myxococcus xanthus

Microbiology ◽  
2006 ◽  
Vol 152 (6) ◽  
pp. 1609-1620 ◽  
Author(s):  
Vinh D. Pham ◽  
Conrad W. Shebelut ◽  
Ivy R. Jose ◽  
David A. Hodgson ◽  
David E. Whitworth ◽  
...  
Keyword(s):  
Histidine Kinase ◽  
Response Regulator ◽  
Myxococcus Xanthus ◽  
Kinase Gene ◽  
Spore Viability ◽  
Phenotypic Differences ◽  
Component Systems ◽  
Two Component Systems ◽  
Identification And Characterization

Phosphate regulation is complex in the developmental prokaryote Myxococcus xanthus, and requires at least four two-component systems (TCSs). Here, the identification and characterization of a member of one TCS, designated PhoP4, is reported. phoP4 insertion and in-frame deletion strains caused spore viability to be decreased by nearly two orders of magnitude, and reduced all three development-specific phosphatase activities by 80–90 % under phosphate-limiting conditions. Microarray and quantitative PCR analyses demonstrated that PhoP4 is also required for appropriate expression of the predicted pstSCAB–phoU operon of inorganic phosphate assimilation genes. Unlike the case for the other three M. xanthus Pho TCSs, the chromosomal region around phoP4 does not contain a partner histidine kinase gene. Yeast two-hybrid analyses reveal that PhoP4 interacts reciprocally with PhoR2, the histidine kinase of the Pho2 TCS; however, the existence of certain phenotypic differences between phoP4 and phoR2 mutants suggests that PhoP4 interacts with another, as-yet unidentified, histidine kinase.

scholarly journals Activation of Bvg-Repressed Genes in Bordetella pertussis by RisA Requires Cross Talk from Noncooperonic Histidine Kinase RisK

2017 ◽  
Vol 199 (22) ◽  
Author(s):  
Qing Chen ◽  
Victoria Ng ◽  
Jason M. Warfel ◽  
Tod J. Merkel ◽  
Scott Stibitz
Keyword(s):  
Bordetella Pertussis ◽  
Histidine Kinase ◽  
Genomic Sequence ◽  
Response Regulator ◽  
Two Component System ◽  
Kinase Gene ◽  
Content Type ◽  
Reading Frame ◽  
Two Component

ABSTRACT The two-component response regulator RisA, encoded by open reading frame BP3554 in the Bordetella pertussis Tohama I genomic sequence, is a known activator of vrg genes, a set of genes whose expression is increased under the same environmental conditions (known as modulation) that result in repression of the bvgAS virulence regulon. Here we demonstrate that RisA is phosphorylated in vivo and that RisA phosphorylation is required for activation of vrg genes. An adjacent histidine kinase gene, risS, is truncated by frameshift mutation in B. pertussis but not in Bordetella bronchiseptica or Bordetella parapertussis. Neither deletion of risS′ or bvgAS nor phenotypic modulation with MgSO4 affected levels of phosphorylated RisA (RisA∼P) in B. pertussis. However, RisA phosphorylation did require the histidine kinase encoded by BP3223, here named RisK (cognate histidine kinase of RisA). RisK was also required for expression of the vrg genes. This requirement could be obviated by the introduction of the phosphorylation-mimicking RisAD60E mutant, indicating that an active conformation of RisA, but not phosphorylation per se, is crucial for vrg activation. Interestingly, expression of vrg genes is still modulated by MgSO4 in cells harboring the RisAD60E mutation, suggesting that the activated RisA senses additional signals to control vrg expression in response to environmental stimuli. IMPORTANCE In B. pertussis, the BvgAS two-component system activates the expression of virulence genes by binding of BvgA∼P to their promoters. Expression of the reciprocally regulated vrg genes requires RisA and is also repressed by the Bvg-activated BvgR. RisA is an OmpR-like response regulator, but RisA phosphorylation was not expected because the gene for its presumed, cooperonic, histidine kinase is inactivated by mutation. In this study, we demonstrate phosphorylation of RisA in vivo by a noncooperonic histidine kinase. We also show that RisA phosphorylation is necessary but not sufficient for vrg activation but, importantly, is not affected by BvgAS status. Instead, we propose that vrg expression is controlled by BvgAS through its regulation of BvgR, a cyclic di-GMP (c-di-GMP) phosphodiesterase.

scholarly journals Isolation and Functional Analysis of a Gene, tcsB, Encoding a Transmembrane Hybrid-Type Histidine Kinase from Aspergillus nidulans

2002 ◽  
Vol 68 (11) ◽  
pp. 5304-5310 ◽  
Author(s):  
Kentaro Furukawa ◽  
Yasuaki Katsuno ◽  
Takeshi Urao ◽  
Tomio Yabe ◽  
Toshiko Yamada-Okabe ◽  
...  
Keyword(s):  
Aspergillus Nidulans ◽  
Histidine Kinase ◽  
Phosphorylation Site ◽  
Structural Similarity ◽  
Mapk Cascade ◽  
Mitogen Activated Protein Kinase ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Kinase Gene ◽  
Hybrid Type

ABSTRACT We cloned and characterized a novel Aspergillus nidulans histidine kinase gene, tcsB, encoding a membrane-type two-component signaling protein homologous to the yeast osmosensor synthetic lethal N-end rule protein 1 (SLN1), which transmits signals through the high-osmolarity glycerol response 1 (HOG1) mitogen-activated protein kinase (MAPK) cascade in yeast cells in response to environmental osmotic stimuli. From an A. nidulans cDNA library, we isolated a positive clone containing a 3,210-bp open reading frame that encoded a putative protein consisting of 1,070 amino acids. The predicted tcsB protein (TcsB) has two probable transmembrane regions in its N-terminal half and has a high degree of structural similarity to yeast Sln1p, a transmembrane hybrid-type histidine kinase. Overexpression of the tcsB cDNA suppressed the lethality of a temperature-sensitive osmosensing-defective sln1-ts yeast mutant. However, tcsB cDNAs in which the conserved phosphorylation site His552 residue or the phosphorelay site Asp989 residue had been replaced failed to complement the sln1-ts mutant. In addition, introduction of the tcsB cDNA into an sln1Δ sho1Δ yeast double mutant, which lacked two osmosensors, suppressed lethality in high-salinity media and activated the HOG1 MAPK. These results imply that TcsB functions as an osmosensor histidine kinase. We constructed an A. nidulans strain lacking the tcsB gene (tcsBΔ) and examined its phenotype. However, unexpectedly, the tcsBΔ strain did not exhibit a detectable phenotype for either hyphal development or morphology on standard or stress media. Our results suggest that A. nidulans has more complex and robust osmoregulatory systems than the yeast SLN1-HOG1 MAPK cascade.

scholarly journals Identification of a Two-Component Regulatory Pathway Essential for Mn(II) Oxidation in Pseudomonas putida GB-1

2009 ◽  
Vol 76 (4) ◽  
pp. 1224-1231 ◽  
Author(s):  
Kati Geszvain ◽  
Bradley M. Tebo
Keyword(s):  
Pseudomonas Putida ◽  
Histidine Kinase ◽  
Response Regulator ◽  
Bacterial Species ◽  
Cosmid Library ◽  
Causative Mutation ◽  
Regulatory Pathway ◽  
Kinase Gene ◽  
Sensor Histidine Kinase ◽  
Two Component

ABSTRACT Bacterial manganese(II) oxidation has a profound impact on the biogeochemical cycling of Mn and the availability of the trace metals adsorbed to the surfaces of solid Mn(III, IV) oxides. The Mn(II) oxidase enzyme was tentatively identified in Pseudomonas putida GB-1 via transposon mutagenesis: the mutant strain GB-1-007, which fails to oxidize Mn(II), harbors a transposon insertion in the gene cumA. cumA encodes a putative multicopper oxidase (MCO), a class of enzymes implicated in Mn(II) oxidation in other bacterial species. However, we show here that an in-frame deletion of cumA did not affect Mn(II) oxidation. Through complementation analysis of the oxidation defect in GB-1-007 with a cosmid library and subsequent sequencing of candidate genes we show the causative mutation to be a frameshift within the mnxS1 gene that encodes a putative sensor histidine kinase. The frameshift mutation results in a truncated protein lacking the kinase domain. Multicopy expression of mnxS1 restored Mn(II) oxidation to GB-1-007 and in-frame deletion of mnxS1 resulted in a loss of oxidation in the wild-type strain. These results clearly demonstrated that the oxidation defect of GB-1-007 is due to disruption of mnxS1, not cumA::Tn5, and that CumA is not the Mn(II) oxidase. mnxS1 is located upstream of a second sensor histidine kinase gene, mnxS2, and a response regulator gene, mnxR. In-frame deletions of each of these genes also led to the loss of Mn(II) oxidation. Therefore, we conclude that the MnxS1/MnxS2/MnxR two-component regulatory pathway is essential for Mn(II) oxidation in P. putida GB-1.

scholarly journals The Response Regulator RRG-1 Functions Upstream of a Mitogen-activated Protein Kinase Pathway Impacting Asexual Development, Female Fertility, Osmotic Stress, and Fungicide Resistance inNeurospora crassa

2007 ◽  
Vol 18 (6) ◽  
pp. 2123-2136 ◽  
Author(s):  
Carol A. Jones ◽  
Suzanne E. Greer-Phillips ◽  
Katherine A. Borkovich
Keyword(s):  
Protein Kinase ◽  
Histidine Kinase ◽  
Fungicide Resistance ◽  
Mapk Pathway ◽  
Response Regulator ◽  
Phosphorylation Site ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Kinase ◽  
Independent Functions ◽  
Mitogen Activated Protein

Two-component systems, consisting of proteins with histidine kinase and/or response regulator domains, regulate environmental responses in bacteria, Archaea, fungi, slime molds, and plants. Here, we characterize RRG-1, a response regulator protein from the filamentous fungus Neurospora crassa. The cell lysis phenotype of Δrrg-1 mutants is reminiscent of osmotic-sensitive (os) mutants, including nik-1/os-1 (a histidine kinase) and strains defective in components of a mitogen-activated protein kinase (MAPK) pathway: os-4 (MAPK kinase kinase), os-5 (MAPK kinase), and os-2 (MAPK). Similar to os mutants, Δrrg-1 strains are sensitive to hyperosmotic conditions, and they are resistant to the fungicides fludioxonil and iprodione. Like os-5, os-4, and os-2 mutants, but in contrast to nik-1/os-1 strains, Δrrg-1 mutants do not produce female reproductive structures (protoperithecia) when nitrogen starved. OS-2-phosphate levels are elevated in wild-type cells exposed to NaCl or fludioxonil, but they are nearly undetectable in Δrrg-1 strains. OS-2-phosphate levels are also low in Δrrg-1, os-2, and os-4 mutants under nitrogen starvation. Analysis of the rrg-1D921Nallele, mutated in the predicted phosphorylation site, provides support for phosphorylation-dependent and -independent functions for RRG-1. The data indicate that RRG-1 controls vegetative cell integrity, hyperosmotic sensitivity, fungicide resistance, and protoperithecial development through regulation of the OS-4/OS-5/OS-2 MAPK pathway.

Characterization of mutations in the two-component histidine kinase gene AbNIK1 from Alternaria brassicicola that confer high dicarboximide and phenylpyrrole resistance

2005 ◽  
Vol 47 (4) ◽  
pp. 234-243 ◽  
Author(s):  
Herv� Avenot ◽  
Philippe Simoneau ◽  
B�atrice Iacomi-Vasilescu ◽  
Nelly Bataill�-Simoneau
Keyword(s):  
Histidine Kinase ◽  
Alternaria Brassicicola ◽  
Kinase Gene ◽  
Two Component
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