scholarly journals The pmk1-like mitogen-activated protein kinase from Lecanicillium (Verticillium) fungicola is not required for virulence on Agaricus bisporus

Microbiology ◽  
2010 ◽  
Vol 156 (5) ◽  
pp. 1439-1447 ◽  
Author(s):  
Patrick D. Collopy ◽  
Richard C. Amey ◽  
Martin J. Sergeant ◽  
Michael P. Challen ◽  
Peter R. Mills ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Agaricus Bisporus ◽  
Plant Pathogens ◽  
Mapk Pathway ◽  
Pathogenic Fungi ◽  
Single Copy ◽  
Mitogen Activated Protein Kinase ◽  
Verticillium Fungicola ◽  
Fungal Plant Pathogens ◽  
Mitogen Activated Protein

In plant-pathogenic fungi, the pmk1 mitogen-activated protein kinase (MAPK) signalling pathway plays an essential role in regulating the development of penetration structures and the sensing of host-derived cues, but its role in other pathosystems such as fungal–fungal interactions is less clear. We report the use of a gene disruption strategy to investigate the pmk1-like MAPK, Lf pmk1 in the development of Lecanicillium fungicola (formerly Verticillium fungicola) infection on the cultivated mushroom Agaricus bisporus. Lf pmk1 was isolated using a degenerate PCR-based approach and was shown to be present in a single copy by Southern blot analysis. Quantitative RT-PCR showed the transcript to be fivefold upregulated in cap lesions compared with pure culture. Agrobacterium-mediated targeted disruption was used to delete a central portion of the Lf pmk1 gene. The resulting mutants showed normal symptom development as assessed by A. bisporus mushroom cap assays, sporulation patterns were normal and there were no apparent changes in overall growth rates. Our results indicate that, unlike the situation in fungal–plant pathogens, the pmk1-like MAPK pathway is not required for virulence in the fungal–fungal interaction between the L. fungicola pathogen and A. bisporus host. This observation may be of wider significance in other fungal–fungal and/or fungal–invertebrate interactions.

scholarly journals The Mitogen-Activated Protein Kinase Gene Crmapk Is Involved in Clonostachys chloroleuca Mycoparasitism

2020 ◽  
Vol 33 (7) ◽  
pp. 902-910
Author(s):  
Zhan-Bin Sun ◽  
Qi Wang ◽  
Man-Hong Sun ◽  
Shi-Dong Li
Keyword(s):  
Protein Kinase ◽  
Plant Pathogens ◽  
Gene Knockout ◽  
Antibiotic Production ◽  
Morphological Characteristics ◽  
Mitogen Activated Protein Kinase ◽  
Sclerotinia Stem Rot ◽  
Cell Wall Degrading Enzymes ◽  
Fungal Plant Pathogens ◽  
Mitogen Activated Protein

Clonostachys chloroleuca is a mycoparasite used for biocontrol of numerous fungal plant pathogens. Sequencing of the transcriptome of C. chloroleuca following mycoparasitization of the sclerotia of Sclerotinia sclerotiorum revealed significant upregulation of a mitogen-activated protein kinase (MAPK)-encoding gene, crmapk. Although MAPKs are known to regulate fungal growth and development, the function of crmapk in C. chloroleuca mycoparasitism is unclear. In this study, we investigated the role of crmapk in C. chloroleuca mycoparasitism through gene knockout and complementation. Deletion of crmapk had no influence on the C. chloroleuca morphological characteristics but could significantly reduce the mycoparasitic ability to sclerotia and biocontrol capacity to soybean Sclerotinia stem rot; crmapk complementation restored these abilities. Transcriptome analysis between Δcrmapk and the wild-type strain revealed numerous genes were significantly down-regulated after crmapk deletion, including cytochrome P450, transporters, and cell wall–degrading enzymes (CWDEs). Our findings indicate that crmapk influences C. chloroleuca mycoparasitism by regulation of genes controlling the activity of CWDEs or antibiotic production. This study provides a basis for further studies of the molecular mechanism of C. chloroleuca mycoparasitism.

scholarly journals TmkA, a Mitogen-Activated Protein Kinase of Trichoderma virens, Is Involved in Biocontrol Properties and Repression of Conidiation in the Dark

2003 ◽  
Vol 2 (3) ◽  
pp. 446-455 ◽  
Author(s):  
Prasun K. Mukherjee ◽  
Jagannathan Latha ◽  
Ruthi Hadar ◽  
Benjamin A. Horwitz
Keyword(s):  
Protein Kinase ◽  
Plant Pathogens ◽  
Sclerotium Rolfsii ◽  
Pathogenic Fungi ◽  
Mitogen Activated Protein Kinase ◽  
Trichoderma Virens ◽  
Loss Of Function ◽  
Wild Type ◽  
Mapk Cascades ◽  
Mitogen Activated Protein

ABSTRACT Trichoderma virens is a mycoparasitic fungus used in biocontrol of soilborne plant pathogens. It inhibits or kills plant-pathogenic fungi through production of antifungal antibiotics and parasitism of hyphae and sclerotia. Conidiation, or the production of asexual spores, an inducible process triggered by light or nutrient stress, is an important trait in survival and also development of formulation products. In many fungi, signaling pathways, including mitogen-activated protein kinase (MAPK) cascades, have been implicated in parasitism of host plants as well as in the production of asexual spores. Here, we have studied the role of a MAPK gene, that for TmkA, in conidiation and antagonistic properties of a biocontrol strain of T. virens. Through single- and double-crossover recombination, we obtained three tmkA loss-of-function mutants. The TmkA transcript was not detectable in these mutants. The mutants conidiated in the dark, although photoinduction was normal and the light sensitivities of the wild type and the mutant were the same. The mutants had, overall, normal colony morphology, but their radial growth rate was reduced by about 16%, with no decrease in biomass production. Against Rhizoctonia solani hyphae, the knockout mutants exhibited mycoparasitic coiling and lysis of host hyphae similar to that of the wild type. The mutants, however, were less effective in colonizing the sclerotia of R. solani. On Sclerotium rolfsii, the MAPK loss-of-function mutants had reduced antagonistic properties in confrontation assays and failed to parasitize the sclerotia. TmkA-dependent and -independent pathways are thus involved in antagonism against different hosts. Finally, in contrast to the case for other filamentous fungi studied so far, signaling through a MAPK represses, rather than induces, asexual sporulation.

scholarly journals Stress-Activated Protein Kinase Signalling Regulates Mycoparasitic Hyphal-Hyphal Interactions in Trichoderma atroviride

2021 ◽  
Vol 7 (5) ◽  
pp. 365
Author(s):  
Dubraska Moreno-Ruiz ◽  
Linda Salzmann ◽  
Mark D. Fricker ◽  
Susanne Zeilinger ◽  
Alexander Lichius
Keyword(s):  
Protein Kinase ◽  
Map Kinases ◽  
Plant Pathogens ◽  
Tip Growth ◽  
Mitogen Activated Protein Kinase ◽  
Trichoderma Atroviride ◽  
Contact Phase ◽  
Fungal Plant Pathogens ◽  
Signalling Network ◽  
Mapk Signalling

Trichoderma atroviride is a mycoparasitic fungus used as biological control agent against fungal plant pathogens. The recognition and appropriate morphogenetic responses to prey-derived signals are essential for successful mycoparasitism. We established microcolony confrontation assays using T. atroviride strains expressing cell division cycle 42 (Cdc42) and Ras-related C3 botulinum toxin substrate 1 (Rac1) interactive binding (CRIB) reporters to analyse morphogenetic changes and the dynamic displacement of localized GTPase activity during polarized tip growth. Microscopic analyses showed that Trichoderma experiences significant polarity stress when approaching its fungal preys. The perception of prey-derived signals is integrated via the guanosine triphosphatase (GTPase) and mitogen-activated protein kinase (MAPK) signalling network, and deletion of the MAP kinases Trichoderma MAPK 1 (Tmk1) and Tmk3 affected T. atroviride tip polarization, chemotropic growth, and contact-induced morphogenesis so severely that the establishment of mycoparasitism was highly inefficient to impossible. The responses varied depending on the prey species and the interaction stage, reflecting the high selectivity of the signalling process. Our data suggest that Tmk3 affects the polarity-stress adaptation process especially during the pre-contact phase, whereas Tmk1 regulates contact-induced morphogenesis at the early-contact phase. Neither Tmk1 nor Tmk3 loss-of-function could be fully compensated within the GTPase/MAPK signalling network underscoring the crucial importance of a sensitive polarized tip growth apparatus for successful mycoparasitism.

scholarly journals Expression of transgenes enriched in rare codons is enhanced by the MAPK pathway

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jackson Peterson ◽  
Siqi Li ◽  
Erin Kaltenbrun ◽  
Ozgun Erdogan ◽  
Christopher M. Counter
Keyword(s):  
Amino Acids ◽  
Protein Kinase ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Rare Codons ◽  
Synonymous Codons ◽  
Multiple Components ◽  
Human Genes ◽  
Regulatory Module ◽  
Mitogen Activated Protein

AbstractThe ability to translate three nucleotide sequences, or codons, into amino acids to form proteins is conserved across all organisms. All but two amino acids have multiple codons, and the frequency that such synonymous codons occur in genomes ranges from rare to common. Transcripts enriched in rare codons are typically associated with poor translation, but in certain settings can be robustly expressed, suggestive of codon-dependent regulation. Given this, we screened a gain-of-function library for human genes that increase the expression of a GFPrare reporter encoded by rare codons. This screen identified multiple components of the mitogen activated protein kinase (MAPK) pathway enhancing GFPrare expression. This effect was reversed with inhibitors of this pathway and confirmed to be both codon-dependent and occur with ectopic transcripts naturally coded with rare codons. Finally, this effect was associated, at least in part, with enhanced translation. We thus identify a potential regulatory module that takes advantage of the redundancy in the genetic code to modulate protein expression.

scholarly journals Ghrelin exerts a proliferative effect on a rat pituitary somatotroph cell line via the mitogen-activated protein kinase pathway

2004 ◽  
pp. 233-240 ◽  
Author(s):  
AM Nanzer ◽  
S Khalaf ◽  
AM Mozid ◽  
RC Fowkes ◽  
MV Patel ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Protein Kinase ◽  
Cell Line ◽  
Kinase Inhibitor ◽  
Thymidine Incorporation ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Gh3 Cells ◽  
Rat Pituitary ◽  
Mitogen Activated Protein

OBJECTIVES: Ghrelin is a brain-gut peptide with GH-releasing and appetite-inducing activities and a widespread tissue distribution. Ghrelin is the endogenous ligand of the GH secretagogue receptor type 1a (GHS-R1a), and both ghrelin and the GHS-R1a are expressed in the pituitary. There are conflicting data regarding the effects of ghrelin on cell proliferation. A positive effect on proliferation and activation of the mitogen-activated protein kinase (MAPK) pathway has been found in hepatoma, adipose, cardiomyocyte and prostate cell lines. However, ghrelin has also been shown to have anti-proliferative effects on breast, lung and thyroid cell lines. We therefore examined the effect of ghrelin on the rat pituitary cell line GH3. METHODS: RT-PCR was used for the detection of GHS-R1a and pre-proghrelin mRNA expression in GH3 cells. The effect of ghrelin on cell proliferation was studied using [(3)H]thymidine incorporation; cell counting and the activation of the MAPK pathway were studied using immunoblotting and inhibitors of the extracellular signal-regulated kinase 1 and 2 (ERK 1/2), protein kinase C (PKC) and tyrosine phosphatase pathways. RESULTS: GHS-R1a and ghrelin mRNA expression were detected in GH3 cells. Ghrelin, at 10(-10) to 10(-6) M concentrations, significantly increased [(3)H]thymidine incorporation (at 10(-9) M, 183+/-13% (means+/-s.e.m.) compared with untreated controls), while 12-phorbol 13-myristate acetate (PMA) at 10(-7) M (used as a positive control) caused a 212+/-14% increase. A reproducible stimulatory effect of desoctanoyl ghrelin was also observed on [(3)H]thymidine incorporation (135+/-5%; P<0.01 at 10(-9) M compared with control), as well as on the cell count (control 6.8 x 10(4)+/-8.7 x 10(3) cells/ml vs desoctanoyl ghrelin (10(-9) M) 1.04 x 10(5)+/-7.5 x 10(3) cells/ml; P<0.01). Ghrelin caused a significant increase in phosphorylated ERK 1/2 in immunoblotting, while desoctanoyl ghrelin showed a smaller but also significant stimulatory effect. The positive effect of ghrelin and desoctanoyl ghrelin on [(3)H]thymidine incorporation was abolished by the MAPK kinase inhibitor U0126, the PKC inhibitor GF109203X and the tyrosine kinase inhibitor tyrphostin 23, suggesting that the ghrelin-induced cell proliferation of GH3 cells is mediated both via a PKC-MAPK-dependent pathway and via a tyrosine kinase-dependent pathway. This could also be clearly demonstrated by Western blot analysis, where a transient increase in ERK 1/2 phosphorylation by ghrelin was attenuated by all three inhibitors. CONCLUSION: We have shown a novel role for ghrelin in stimulating the proliferation of a somatotroph pituitary tumour cell line, suggesting that ERK activation is involved in mediating the effects of ghrelin on cell proliferation. Desoctanoyl ghrelin showed a similar effect. As ghrelin has been shown to be expressed in both normal and adenomatous pituitary tissue, locally produced ghrelin may play a role in pituitary tumorigenesis via an autocrine/paracrine pathway.

scholarly journals Protein Kinase A Operates a Molecular Switch That Governs Yeast Pseudohyphal Differentiation

2002 ◽  
Vol 22 (12) ◽  
pp. 3981-3993 ◽  
Author(s):  
Xuewen Pan ◽  
Joseph Heitman
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Pathogenic Fungi ◽  
Mitogen Activated Protein Kinase ◽  
Signaling Cascades ◽  
Mitogen Activated Protein ◽  
Eukaryotic Organisms ◽  
Pseudohyphal Differentiation ◽  
Developmental Switch ◽  
Kinase A

ABSTRACT The yeast Saccharomyces cerevisiae undergoes a dimorphic filamentous transition in response to nutrient cues that is affected by both mitogen-activated protein kinase and cyclic AMP-protein kinase A signaling cascades. Here two transcriptional regulators, Flo8 and Sfl1, are shown to be the direct molecular targets of protein kinase A. Flo8 and Sfl1 antagonistically control expression of the cell adhesin Flo11 via a common promoter element. Phosphorylation by the protein kinase A catalytic subunit Tpk2 promotes Flo8 binding and activation of the Flo11 promoter and relieves repression by prohibiting dimerization and DNA binding by Sfl1. Our studies illustrate in molecular detail how protein kinase A combinatorially effects a key developmental switch. Similar mechanisms may operate in pathogenic fungi and more complex multicellular eukaryotic organisms.

scholarly journals The vaccinia virus-stimulated mitogen-activated protein kinase (MAPK) pathway is required for virus multiplication

2004 ◽  
Vol 381 (2) ◽  
pp. 437-446 ◽  
Author(s):  
Anderson A. ANDRADE ◽  
Patrícia N. G. SILVA ◽  
Anna C. T. C. PEREIRA ◽  
Lirlândia P. de SOUSA ◽  
Paulo C. P. FERREIRA ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Tyrosine Kinase ◽  
Vaccinia Virus ◽  
Mapk Pathway ◽  
Decisive Role ◽  
Virus Multiplication ◽  
Mitogen Activated Protein Kinase ◽  
Actin Dynamics ◽  
Kinase Activation ◽  
Mitogen Activated Protein

Early events play a decisive role in virus multiplication. We have shown previously that activation of MAPK/ERK1/2 (mitogen-activated protein kinase/extracellular-signal-regulated kinase 1/2) and protein kinase A are pivotal for vaccinia virus (VV) multiplication [de Magalhães, Andrade, Silva, Sousa, Ropert, Ferreira, Kroon, Gazzinelli and Bonjardim (2001) J. Biol. Chem. 276, 38353–38360]. In the present study, we show that VV infection provoked a sustained activation of both ERK1/2 and RSK2 (ribosomal S6 kinase 2). Our results also provide evidence that this pattern of kinase activation depends on virus multiplication and ongoing protein synthesis and is maintained independently of virus DNA synthesis. It is noteworthy that the VGF (VV growth factor), although involved, is not essential for prolonged ERK1/2 activation. Furthermore, our findings suggest that the VV-stimulated ERK1/2 activation also seems to require actin dynamics, microtubule polymerization and tyrosine kinase phosphorylation. The VV-stimulated pathway MEK/ERK1/2/RSK2 (where MEK stands for MAPK/ERK kinase) leads to phosphorylation of the ternary complex factor Elk-1 and expression of the early growth response (egr-1) gene, which kinetically paralleled the kinase activation. The recruitment of this pathway is biologically relevant, since its disruption caused a profound effect on viral thymidine kinase gene expression, viral DNA replication and VV multiplication. This pattern of sustained kinase activation after VV infection is unique. In addition, by connecting upstream signals generated at the cytoskeleton and by tyrosine kinase, the MEK/ERK1/2/RSK2 cascade seems to play a decisive role not only at early stages of the infection, i.e. post-penetration, but is also crucial to define the fate of virus progeny.

scholarly journals APPL1 mediates adiponectin-stimulated p38 MAPK activation by scaffolding the TAK1-MKK3-p38 MAPK pathway

2011 ◽  
Vol 300 (1) ◽  
pp. E103-E110 ◽  
Author(s):  
Xiaoban Xin ◽  
Lijun Zhou ◽  
Caleb M. Reyes ◽  
Feng Liu ◽  
Lily Q. Dong
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Adaptor Protein ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Scaffolding Protein ◽  
Mapk Activation ◽  
P38 Mapk Pathway ◽  
Mitogen Activated Protein

The adaptor protein APPL1 mediates the stimulatory effect of adiponectin on p38 mitogen-activated protein kinase (MAPK) signaling, yet the underlying mechanism remains unclear. Here we show that, in C2C12 cells, overexpression or suppression of APPL1 enhanced or suppressed, respectively, adiponectin-stimulated p38 MAPK upstream kinase cascade, consisting of transforming growth factor-β-activated kinase 1 (TAK1) and mitogen-activated protein kinase kinase 3 (MKK3). In vitro affinity binding and coimmunoprecipitation experiments revealed that TAK1 and MKK3 bind to different regions of APPL1, suggesting that APPL1 functions as a scaffolding protein to facilitate adiponectin-stimulated p38 MAPK activation. Interestingly, suppressing APPL1 had no effect on TNFα-stimulated p38 MAPK phosphorylation in C2C12 myotubes, indicating that the stimulatory effect of APPL1 on p38 MAPK activation is selective. Taken together, our study demonstrated that the TAK1-MKK3 cascade mediates adiponectin signaling and uncovers a scaffolding role of APPL1 in regulating the TAK1-MKK3-p38 MAPK pathway, specifically in response to adiponectin stimulation.

scholarly journals Both Binding and Activation of p38 Mitogen-Activated Protein Kinase (MAPK) Play Essential Roles in Regulation of the Nucleocytoplasmic Distribution of MAPK-Activated Protein Kinase 5 by Cellular Stress

2002 ◽  
Vol 22 (20) ◽  
pp. 6931-6945 ◽  
Author(s):  
Ole Morten Seternes ◽  
Bjarne Johansen ◽  
Beate Hegge ◽  
Mona Johannessen ◽  
Stephen M. Keyse ◽  
...  
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Nuclear Export ◽  
Fluorescent Protein ◽  
Mapk Pathway ◽  
Nuclear Export Signal ◽  
Mitogen Activated Protein Kinase ◽  
Protein Fusion ◽  
Translational Machinery ◽  
Mitogen Activated Protein

ABSTRACT The p38 mitogen-activated protein kinase (MAPK) pathway is an important mediator of cellular responses to environmental stress. Targets of p38 include transcription factors, components of the translational machinery, and downstream serine/threonine kinases, including MAPK-activated protein kinase 5 (MK5). Here we have used enhanced green fluorescent protein fusion proteins to analyze the subcellular localization of MK5. Although this protein is predominantly nuclear in unstimulated cells, MK5 shuttles between the nucleus and the cytoplasm. Furthermore, we have shown that the C-terminal domain of MK5 contains both a functional nuclear localization signal (NLS) and a leucine-rich nuclear export signal (NES), indicating that the subcellular distribution of this kinase reflects the relative activities of these two signals. In support of this, we have shown that stress-induced activation of the p38 MAPK stimulates the chromosomal region maintenance 1 protein-dependent nuclear export of MK5. This is regulated by both binding of p38 MAPK to MK5, which masks the functional NLS, and stress-induced phosphorylation of MK5 by p38 MAPK, which either activates or unmasks the NES. These properties may define the ability of MK5 to differentially phosphorylate both nuclear and cytoplasmic targets or alternatively reflect a mechanism whereby signals initiated by activation of MK5 in the nucleus may be transmitted to the cytoplasm.

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