scholarly journals Fungal Jasmonate as a Novel Morphogenetic Signal for Pathogenesis

2021 ◽  
Vol 7 (9) ◽  
pp. 693
Author(s):  
Yingyao Liu ◽  
Martin Pagac ◽  
Fan Yang ◽  
Rajesh N. Patkar ◽  
Naweed I. Naqvi
Keyword(s):  
Vegetative Growth ◽  
Rice Blast ◽  
Pathogenic Fungi ◽  
Camp Signaling ◽  
Epistasis Analysis ◽  
Camp Pathway ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Delayed Initiation ◽  
Consequent Reduction

A key question that has remained unanswered is how pathogenic fungi switch from vegetative growth to infection-related morphogenesis during a disease cycle. Here, we identify a fungal oxylipin analogous to the phytohormone jasmonic acid (JA), as the principal regulator of such a developmental switch to isotropic growth and pathogenicity in the rice-blast fungus Magnaporthe oryzae. Using specific inhibitors and mutant analyses, we determined the molecular function of intrinsic jasmonates during M. oryzae pathogenesis. Loss of 12-Oxo-phytodienoic Acid (OPDA) Reductase and/or consequent reduction of jasmonate biosynthesis, prolonged germ tube growth and caused delayed initiation and improper development of infection structures in M. oryzae, reminiscent of phenotypic defects upon impaired cyclic AMP (cAMP) signaling. Chemical- or genetic-complementation completely restored proper vegetative growth and appressoria in opr1Δ. Mass spectrometry-based quantification revealed increased OPDA accumulation and significantly decreased jasmonate levels in opr1Δ. Most interestingly, exogenous jasmonate restored proper appressorium formation in pth11Δ that lacks G protein/cAMP signaling; but failed to do so in the Mitogen-activated protein (MAP) kinase mutants. Epistasis analysis placed jasmonate upstream of the cAMP pathway in rice blast. Mechanistically, intrinsic jasmonate orchestrates timely cessation of the vegetative phase and induces pathogenic development via a complex regulatory interaction with the cAMP-PKA cascade and redox signaling in rice blast.

scholarly journals Fungal jasmonate as a novel morphogenetic signal for pathogenesis

2021 ◽  
Author(s):  
Yingyao Liu ◽  
Martin Pagac ◽  
Fan Yang ◽  
Rajesh Narhari Patkar ◽  
Naweed I Naqvi
Keyword(s):  
Cyclic Amp ◽  
Jasmonic Acid ◽  
Vegetative Growth ◽  
Rice Blast ◽  
Pathogenic Fungi ◽  
Appressorium Formation ◽  
Epistasis Analysis ◽  
Delayed Initiation ◽  
Developmental Switch ◽  
Cyclic Amp Signaling

A key question that has remained unanswered is how pathogenic fungi switch from vegetative growth to infection-related morphogenesis during a disease cycle. Here, we identify a fungal oxylipin analogous to the well-known phytohormone jasmonic acid, as the principal morphogenesis signal responsible for such a developmental switch to pathogenicity in the rice-blast fungus Magnaporthe oryzae. We explored the molecular function(s) of such intrinsic jasmonic acid during pathogenic differentiation in M. oryzae via OPR1, which encodes a 12-Oxo-phytodienoic Acid Reductase essential for its biosynthesis. Loss of OPR1 led to prolonged vegetative growth, and a delayed initiation and improper development of infection structures in M. oryzae, reminiscent of phenotypes observed in mutants (e.g. pth11Δ and cpkAΔ) that are compromised for cyclic AMP signaling. Genetic- or chemical-complementation completely restored proper germ tube growth and appressorium formation in opr1Δ. Liquid chromatography mass spectrometry-based quantification revealed increased OPDA accumulation and a significant decrease in JA levels in the opr1Δ. Most interestingly, exogenous jasmonic acid also restored appressorium formation in the pth11Δ mutant that lacks G protein/cyclic AMP signaling. Epistasis analysis placed fungal jasmonate upstream of the cyclic AMP signaling in rice blast. Lastly, we show that intrinsic jasmonate orchestrates the cessation of vegetative phase and initiates pathogenic development via a regulatory interaction with the cyclic AMP cascade and redox signaling in rice blast.

scholarly journals Candida albicans Forms a Specialized “Sexual” as Well as “Pathogenic” Biofilm

2013 ◽  
Vol 12 (8) ◽  
pp. 1120-1131 ◽  
Author(s):  
Yang-Nim Park ◽  
Karla J. Daniels ◽  
Claude Pujol ◽  
Thyagarajan Srikantha ◽  
David R. Soll
Keyword(s):  
Candida Albicans ◽  
Cyclic Amp ◽  
Type Locus ◽  
Content Type ◽  
Camp Pathway ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Fluconazole Resistant ◽  
Map Kinase Pathway ◽  
Kinase Pathway

ABSTRACTCandida albicansforms two types of biofilm in RPMI 1640 medium, depending upon the configuration of the mating type locus. In the prevalenta/α configuration, cells form a biofilm that is impermeable, impenetrable by leukocytes, and fluconazole resistant. It is regulated by the Ras1/cyclic AMP (cAMP) pathway. In thea/aor α/α configuration, white cells form a biofilm that is architecturally similar to ana/α biofilm but, in contrast, is permeable, penetrable, and fluconazole susceptible. It is regulated by the mitogen-activated protein (MAP) kinase pathway. TheMTL-homozygous biofilm has been shown to facilitate chemotropism, a step in the mating process. This has led to the hypothesis that specializedMTL-homozygous biofilms facilitate mating. If true, thenMTL-homozygous biofilms should have an advantage overMTL-heterozygous biofilms in supporting mating. We have tested this prediction using a complementation strategy and show that minority opaquea/aand α/α cells seeded inMTL-homozygous biofilms mate at frequencies 1 to 2 orders of magnitude higher than inMTL-heterozygous biofilms. No difference in mating frequencies was observed between seeded patches ofMTL-heterozygous andMTL-homozygous cells grown on agar at 28°C in air or 20% CO2and at 37°C. Mating frequencies are negligible in seeded patches of botha/α anda/acells, in contrast to seeded biofilms. Together, these results support the hypothesis thatMTL-homozygous (a/aor α/α) white cells form a specialized “sexual biofilm.”

scholarly journals Mitogen-Activated Protein (MAP) Kinase Pathways: Regulation and Physiological Functions*

2001 ◽  
Vol 22 (2) ◽  
pp. 153-183 ◽  
Author(s):  
Gray Pearson ◽  
Fred Robinson ◽  
Tara Beers Gibson ◽  
Bing-e Xu ◽  
Mahesh Karandikar ◽  
...  
Keyword(s):  
Map Kinase ◽  
Physiological Functions ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Map Kinase Pathways

scholarly journals Saccharomyces boulardii Preserves the Barrier Function and Modulates the Signal Transduction Pathway Induced in Enteropathogenic Escherichia coli-Infected T84 Cells

2000 ◽  
Vol 68 (10) ◽  
pp. 5998-6004 ◽  
Author(s):  
Dorota Czerucka ◽  
Stephanie Dahan ◽  
Baharia Mograbi ◽  
Bernard Rossi ◽  
Patrick Rampal
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Signal Transduction Pathway ◽  
Specific Inhibitor ◽  
Saccharomyces Boulardii ◽  
Intracellular Bacteria ◽  
T84 Cells ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Map Kinase Pathway

ABSTRACT Use of the nonpathogenic yeast Saccharomyces boulardiiin the treatment of infectious diarrhea has attracted growing interest. The present study designed to investigate the effect of this yeast on enteropathogenic Escherichia coli (EPEC)-associated disease demonstrates that S. boulardii abrogated the alterations induced by an EPEC strain on transepithelial resistance, [3H]inulin flux, and ZO-1 distribution in T84 cells. Moreover, EPEC-mediated apoptosis of epithelial cells was delayed in the presence of S. boulardii. The yeast did not modify the number of adherent bacteria but lowered by 50% the number of intracellular bacteria. Infection by EPEC induced tyrosine phosphorylation of several proteins in T84 cells, including p46 and p52 SHC isoforms, that was attenuated in the presence of S. boulardii. Similarly, EPEC-induced activation of the ERK1/2 mitogen-activated protein (MAP) kinase pathway was diminished in the presence of the yeast. Interestingly, inhibition of the ERK1/2 pathway with the specific inhibitor PD 98059 decreased EPEC internalization, suggesting that modulation of the ERK1/2 MAP pathway might account for the lowering of the number of intracellular bacteria observed in the presence of S. boulardii. Altogether, this study demonstrated that S. boulardii exerts a protective effect on epithelial cells after EPEC adhesion by modulating the signaling pathway induced by bacterial infection.

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 Anisomycin-activated protein kinases p45 and p55 but not mitogen-activated protein kinases ERK-1 and -2 are implicated in the induction of c-fos and c-jun.

1994 ◽  
Vol 14 (11) ◽  
pp. 7352-7362 ◽  
Author(s):  
E Cano ◽  
C A Hazzalin ◽  
L C Mahadevan
Keyword(s):  
Protein Kinases ◽  
Map Kinases ◽  
Early Gene ◽  
Intracellular Signals ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Serine Kinases ◽  
Translational Arrest ◽  
Epidermal Growth ◽  
Nuclear Responses

Independent of its ability to block translation, anisomycin intrinsically initiates intracellular signals and immediate-early gene induction [L. C. Mahadevan and D. R. Edwards, Nature (London) 349:747-749, 1991]. Here, we characterize further its action as a potent, selective signalling agonist. In-gel kinase assays show that epidermal growth factor (EGF) transiently activates five kinases: the mitogen-activated protein (MAP) kinases ERK-1 and -2, and three others, p45, p55, and p80. Anisomycin, at inhibitory and subinhibitory concentrations, does not activate ERK-1 and -2 but elicits strong sustained activation of p45 and p55, which are unique in being serine kinases whose detection is enhanced with poly-Glu/Tyr or poly-Glu/Phe copolymerized in these gels. Translational arrest using emetine or puromycin does not activate p45 and p55 but does prolong EGF-stimulated ERK-1 and -2 activation. Rapamycin, which blocks anisomycin-stimulated p70/85S6k activation without affecting nuclear responses, has no effect on p45 or p55 kinase. p45 and p55 are activable by okadaic acid or UV irradiation, and both kinases phosphorylate the c-Jun NH2-terminal peptide 1-79, putatively placing them within c-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK) subfamily of MAP kinases. Thus, the EGF- and anisomycin-activated kinases p45 and p55 are strongly implicated in signalling to c-fos and c-jun, whereas the MAP kinases ERK-1 and -2 are not essential for this process.

Anisomycin-activated protein kinases p45 and p55 but not mitogen-activated protein kinases ERK-1 and -2 are implicated in the induction of c-fos and c-jun

1994 ◽  
Vol 14 (11) ◽  
pp. 7352-7362 ◽  
Author(s):  
E Cano ◽  
C A Hazzalin ◽  
L C Mahadevan
Keyword(s):  
Protein Kinases ◽  
Map Kinases ◽  
Early Gene ◽  
Intracellular Signals ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Serine Kinases ◽  
Translational Arrest ◽  
Epidermal Growth ◽  
Nuclear Responses

Independent of its ability to block translation, anisomycin intrinsically initiates intracellular signals and immediate-early gene induction [L. C. Mahadevan and D. R. Edwards, Nature (London) 349:747-749, 1991]. Here, we characterize further its action as a potent, selective signalling agonist. In-gel kinase assays show that epidermal growth factor (EGF) transiently activates five kinases: the mitogen-activated protein (MAP) kinases ERK-1 and -2, and three others, p45, p55, and p80. Anisomycin, at inhibitory and subinhibitory concentrations, does not activate ERK-1 and -2 but elicits strong sustained activation of p45 and p55, which are unique in being serine kinases whose detection is enhanced with poly-Glu/Tyr or poly-Glu/Phe copolymerized in these gels. Translational arrest using emetine or puromycin does not activate p45 and p55 but does prolong EGF-stimulated ERK-1 and -2 activation. Rapamycin, which blocks anisomycin-stimulated p70/85S6k activation without affecting nuclear responses, has no effect on p45 or p55 kinase. p45 and p55 are activable by okadaic acid or UV irradiation, and both kinases phosphorylate the c-Jun NH2-terminal peptide 1-79, putatively placing them within c-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK) subfamily of MAP kinases. Thus, the EGF- and anisomycin-activated kinases p45 and p55 are strongly implicated in signalling to c-fos and c-jun, whereas the MAP kinases ERK-1 and -2 are not essential for this process.

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