scholarly journals An RXLR effector secreted by Phytophthora parasitica is a virulence factor and triggers cell death in various plants

2018 ◽  
Vol 20 (3) ◽  
pp. 356-371 ◽  
Author(s):  
Guiyan Huang ◽  
Zhirou Liu ◽  
Biao Gu ◽  
Hong Zhao ◽  
Jinbu Jia ◽  
...  
Keyword(s):  
Cell Death ◽  
Virulence Factor ◽  
Phytophthora Parasitica ◽  
Rxlr Effector

scholarly journals Genome-Wide Identification of M35 Family Metalloproteases in Rhizoctonia cerealis and Functional Analysis of RcMEP2 as a Virulence Factor during the Fungal Infection to Wheat

2020 ◽  
Vol 21 (8) ◽  
pp. 2984
Author(s):  
Lijun Pan ◽  
Shengxian Wen ◽  
Jinfeng Yu ◽  
Lin Lu ◽  
Xiuliang Zhu ◽  
...  
Keyword(s):  
Cell Death ◽  
Virulence Factor ◽  
Signal Peptide ◽  
Triticum Aestivum L ◽  
Phytopathogenic Fungi ◽  
Fungus Infection ◽  
Genome Wide ◽  
Sharp Eyespot ◽  
Causal Pathogen ◽  
Rhizoctonia Cerealis

Rhizoctonia cerealis is the causal pathogen of the devastating disease, sharp eyespot, of the important crop wheat (Triticum aestivum L.). In phytopathogenic fungi, several M36 metalloproteases have been implicated in virulence, but pathogenesis roles of M35 family metalloproteases are largely unknown. Here, we identified four M35 family metalloproteases from R. cerealis genome, designated RcMEP2–RcMEP5, measured their transcriptional profiles, and investigated RcMEP2 function. RcMEP2-RcMEP5 are predicted as secreted metalloproteases since each protein sequence contains a signal peptide and an M35 domain that includes two characteristic motifs HEXXE and GTXDXXYG. Transcription levels of RcMEP2-RcMEP5 markedly elevated during the fungus infection to wheat, among which RcMEP2 expressed with the highest level. Functional dissection indicated that RcMEP2 and its M35 domain could trigger H2O2 rapidly-excessive accumulation, induce cell death, and inhibit expression of host chitinases. This consequently enhanced the susceptibility of wheat to R. cerealis and the predicated signal peptide of RcMEP2 functions required for secretion and cell death-induction. These results demonstrate that RcMEP2 is a virulence factor and that its M35 domain and signal peptide are necessary for the virulence role of RcMEP2. This study facilitates a better understanding of the pathogenesis mechanism of metalloproteases in phytopathogens including R. cerealis.

scholarly journals CMPG1-dependent cell death follows perception of diverse pathogen elicitors at the host plasma membrane and is suppressed by Phytophthora infestans RXLR effector AVR3a

2011 ◽  
Vol 190 (3) ◽  
pp. 653-666 ◽  
Author(s):  
Eleanor M. Gilroy ◽  
Rosalind M. Taylor ◽  
Ingo Hein ◽  
Petra Boevink ◽  
Ari Sadanandom ◽  
...  
Keyword(s):  
Cell Death ◽  
Plasma Membrane ◽  
Phytophthora Infestans ◽  
Rxlr Effector ◽  
Host Plasma Membrane ◽  
Dependent Cell

scholarly journals Plant-induced cell death in the oomycete pathogen Phytophthora parasitica

2005 ◽  
Vol 7 (9) ◽  
pp. 1365-1378 ◽  
Author(s):  
Eric Galiana ◽  
Marie-Pierre Rivière ◽  
Sophie Pagnotta ◽  
Emmanuel Baudouin ◽  
Franck Panabières ◽  
...  
Keyword(s):  
Cell Death ◽  
Phytophthora Parasitica ◽  
Oomycete Pathogen

scholarly journals Aggregatibacter actinomycetemcomitansLeukotoxin (LtxA) Requires Death Receptor Fas, in Addition to LFA-1, To Trigger Cell Death in T Lymphocytes

2019 ◽  
Vol 87 (8) ◽  
Author(s):  
Brian A. Vega ◽  
Liam T. Schober ◽  
Tami Kim ◽  
Benjamin A. Belinka ◽  
Scott C. Kachlany
Keyword(s):  
Cell Death ◽  
T Lymphocytes ◽  
Virulence Factor ◽  
Therapeutic Agent ◽  
White Blood Cells ◽  
Death Receptor ◽  
Aggressive Periodontitis ◽  
Lymphocyte Function ◽  
Content Type ◽  
Trade Name

ABSTRACTLeukotoxin (LtxA) (trade name, Leukothera) is a protein secreted by the oral bacteriumAggregatibacter actinomycetemcomitans.A. actinomycetemcomitansis an oral pathogen strongly associated with development of localized aggressive periodontitis. LtxA acts as a virulence factor forA. actinomycetemcomitansby binding to the β2integrin lymphocyte function-associated antigen-1 (LFA-1; CD11a/CD18) on white blood cells (WBCs) and causing cell death. In addition, because of its specificity for malignant and activated WBCs, LtxA is being investigated as a therapeutic agent for treatment of hematological malignancies and autoimmune diseases. Here, we report the successful generation and characterization of Jurkat T lymphocytes with deletions in CD18, CD11a, and Fas that were engineered using CRISPR/Cas9 gene editing. Using these clones, we demonstrate the specificity of LtxA for cells expressing LFA-1. We also demonstrate the requirement of the cell death receptor Fas for LtxA-mediated cell death in T lymphocytes. We show that LFA-1 and Fas are early events in the LtxA-mediated cell death cascade as caspase activation and mitochondrial perturbation do not occur in the absence of either receptor. To our knowledge, LtxA is the first molecule, other than FasL, known to require the Fas death receptor to initiate cell death. Knowledge of the mechanism of cell death induced by LtxA will facilitate the understanding of LtxA as a bacterial virulence factor and development of it as a potential therapeutic agent.

scholarly journals Xanthomonas Filamentous Hemagglutinin-Like Protein Fha1 Interacts with Pepper Hypersensitive-Induced Reaction Protein CaHIR1 and Functions as a Virulence Factor in Host Plants

2013 ◽  
Vol 26 (12) ◽  
pp. 1441-1454 ◽  
Author(s):  
Hyong Woo Choi ◽  
Dae Sung Kim ◽  
Nak Hyun Kim ◽  
Ho Won Jung ◽  
Jong Hyun Ham ◽  
...  
Keyword(s):  
Cell Death ◽  
Virulence Factor ◽  
Xanthomonas Campestris ◽  
Host Plants ◽  
Bimolecular Fluorescence Complementation ◽  
In Planta ◽  
Pr Genes ◽  
Filamentous Hemagglutinin ◽  
Cell Death Response ◽  
Induced Reaction

Pathogens have evolved a variety of virulence factors to infect host plants successfully. We previously identified the pepper plasma-membrane-resident hypersensitive-induced reaction protein (CaHIR1) as a regulator of plant disease- and immunity-associated cell death. Here, we identified the small filamentous hemagglutinin-like protein (Fha1) of Xanthomonas campestris pv. vesicatoria as an interacting partner of CaHIR1 using yeast two-hybrid screening. Coimmunoprecipitation and bimolecular fluorescence complementation experiments revealed that Fha1 specifically interacts with CaHIR1 in planta. The endocytic tracker FM4-64 staining showed that the CaHIR1-Fha1 complex localizes in the endocytic vesicle-like structure. The X. campestris pv. vesicatoria Δfha1 mutant strain exhibited significantly increased surface adherence but reduced swarming motility. Mutation of fha1 inhibited the growth of X. campestris pv. vesicatoria and X. campestris pv. vesicatoria ΔavrBsT in tomato and pepper leaves, respectively, suggesting that Fha1 acts as a virulence factor in host plants. Transient expression of fha1 and also infiltration with purified Fha1 proteins induced disease-associated cell death response through the interaction with CaHIR1 and suppressed the expression of pathogenesis-related (PR) genes. Silencing of CaHIR1 in pepper significantly reduced ΔavrBsT growth and Fha1-triggered susceptibility cell death. Overexpression of fha1 in Arabidopsis retarded plant growth and triggered disease-associated cell death, resulting in altered disease susceptibility. Taken together, these results suggest that the X. campestris pv. vesicatoria virulence factor Fha1 interacts with CaHIR1, induces susceptibility cell death, and suppresses PR gene expression in host plants.

scholarly journals Tomato SOBIR1/EVR Homologs Are Involved in Elicitin Perception and Plant Defense Against the Oomycete Pathogen Phytophthora parasitica

2015 ◽  
Vol 28 (8) ◽  
pp. 913-926 ◽  
Author(s):  
Ke-Chun Peng ◽  
Chao-Wen Wang ◽  
Chih-Hang Wu ◽  
Chun-Tzu Huang ◽  
Ruey-Fen Liou
Keyword(s):  
Cell Death ◽  
Plant Defense ◽  
Marker Gene ◽  
Defense Responses ◽  
Kinase Domain ◽  
Phytophthora Parasitica ◽  
Callose Deposition ◽  
Molecular Pattern ◽  
Molecular Events ◽  
Species Production

During host-pathogen interactions, pattern recognition receptors form complexes with proteins, such as receptor-like kinases, to elicit pathogen-associated molecular pattern-triggered immunity (PTI), an evolutionarily conserved plant defense program. However, little is known about the components of the receptor complex, as are the molecular events leading to PTI induced by the oomycete Phytophthora pathogen. Here, we demonstrate that tomato (Solanum lycopersicum) SlSOBIR1 and SlSOBIR1-like genes are involved in defense responses to Phytophthora parasitica. Silencing of SlSOBIR1 and SlSOBIR1-like enhanced susceptibility to P. parasitica in tomato. Callose deposition, reactive oxygen species production, and PTI marker gene expression were compromised in SlSOBIR1- and SlSOBIR1-like–silenced plants. Interestingly, P. parasitica infection and elicitin (ParA1) treatment induced the relocalization of SlSOBIR1 from the plasma membrane to endosomal compartments and silencing of NbSOBIR1 compromised ParA1-mediated cell death on Nicotiana benthamiana. Moreover, the SlSOBIR1 kinase domain is indispensable for ParA1 to trigger SlSOBIR1 internalization and plant cell death. Taken together, these results support the idea of participation of solanaceous SOBIR1/EVR homologs in the perception of elicitins and indicate their important roles in plant basal defense against oomycete pathogens.

scholarly journals Adenylate Kinase as a Virulence Factor ofPseudomonas aeruginosa

2001 ◽  
Vol 183 (11) ◽  
pp. 3345-3352 ◽  
Author(s):  
Adam Markaryan ◽  
Olga Zaborina ◽  
Vasu Punj ◽  
A. M. Chakrabarty
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Cell Death ◽  
Virulence Factor ◽  
Adenylate Kinase ◽  
Adenine Nucleotides ◽  
Macrophage Cell ◽  
Cystic Fibrosis Isolate ◽  
Macrophage Killing

ABSTRACT Adenylate kinase (AK; ATP:AMP phosphotransferase, EC 2.7.4.3 ) is a ubiquitous enzyme that contributes to the homeostasis of adenine nucleotides in eukaryotic and prokaryotic cells. AK catalyzes the reversible reaction Mg · ATP + AMP ↔ Mg · ADP + ADP. In this study we show that AK secreted by the pathogenic strains of Pseudomonas aeruginosa appears to play an important role in macrophage cell death. We purified and characterized AK from the growth medium of a cystic fibrosis isolate strain of P. aeruginosa 8821 and hyperproduced it as a fusion protein with glutathione S-transferase. We demonstrated enhanced macrophage cell death in the presence of both the secreted and recombinant purified AK and its substrates AMP plus ATP or ADP. These data suggested that AK converts its substrates to a mixture of AMP, ADP, and ATP, which are potentially more cytotoxic than ATP alone. In addition, we observed increased macrophage killing in the presence of AK and ATP alone. Since the presence of ATPase activity on the macrophages was confirmed in the present work, external macrophage-effluxed ATP is converted to ADP, which in turn can be transformed by AK into a cytotoxic mixture of three adenine nucleotides. Evidence is presented in this study that secreted AK was detected in macrophages during infection with P. aeruginosa. Thus, the possible role of secreted AK as a virulence factor is in producing and keeping an intact pool of toxic mixtures of AMP, ADP, and ATP, which allows P. aeruginosa to exert its full virulence.

scholarly journals Alternative Splicing of a Multi-Drug Transporter from Pseudoperonospora cubensis Generates an RXLR Effector Protein That Elicits a Rapid Cell Death

PLoS ONE ◽  
2012 ◽  
Vol 7 (4) ◽  
pp. e34701 ◽  
Author(s):  
Elizabeth A. Savory ◽  
Cheng Zou ◽  
Bishwo N. Adhikari ◽  
John P. Hamilton ◽  
C. Robin Buell ◽  
...  
Keyword(s):  
Cell Death ◽  
Alternative Splicing ◽  
Pseudoperonospora Cubensis ◽  
Effector Protein ◽  
Drug Transporter ◽  
Rxlr Effector

scholarly journals Pleiotropic molecular effects of the Mycobacterium ulcerans virulence factor mycolactone underlying the cell death and immunosuppression seen in Buruli ulcer

2014 ◽  
Vol 42 (1) ◽  
pp. 177-183 ◽  
Author(s):  
Belinda Hall ◽  
Rachel Simmonds
Keyword(s):  
Cell Death ◽  
Virulence Factor ◽  
Cell Biology ◽  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Prolonged Exposure ◽  
Buruli Ulcer ◽  
Eukaryotic Cell ◽  
Cellular Systems ◽  
Mycobacterium Ulcerans

Mycolactone is a polyketide macrolide lipid-like secondary metabolite synthesized by Mycobacterium ulcerans, the causative agent of BU (Buruli ulcer), and is the only virulence factor for this pathogen identified to date. Prolonged exposure to high concentrations of mycolactone is cytotoxic to diverse mammalian cells (albeit with varying efficiency), whereas at lower doses it has a spectrum of immunosuppressive activities. Combined, these pleiotropic properties have a powerful influence on local and systemic cellular function that should explain the pathophysiology of BU disease. The last decade has seen significant advances in our understanding of the molecular mechanisms underlying these effects in a range of different cell types. The present review focuses on the current state of our knowledge of mycolactone function, and its molecular and cellular targets, and seeks to identify commonalities between the different functional and cellular systems. Since mycolactone influences fundamental cellular processes (cell division, cell death and inflammation), getting to the root of how mycolactone achieves this could have a profound impact on our understanding of eukaryotic cell biology.

scholarly journals An RXLR effector PlAvh142 from Peronophythora litchii triggers plant cell death and contributes to virulence

2020 ◽  
Vol 21 (3) ◽  
pp. 415-428 ◽  
Author(s):  
Junjian Situ ◽  
Liqun Jiang ◽  
Xiaoning Fan ◽  
Wensheng Yang ◽  
Wen Li ◽  
...  
Keyword(s):  
Cell Death ◽  
Plant Cell ◽  
Rxlr Effector
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