scholarly journals Wheat PR-1 proteins are targeted by necrotrophic pathogen effector proteins

2016 ◽  
Vol 88 (1) ◽  
pp. 13-25 ◽  
Author(s):  
Susan Breen ◽  
Simon J. Williams ◽  
Britta Winterberg ◽  
Bostjan Kobe ◽  
Peter S. Solomon
Keyword(s):  
Effector Proteins ◽  
Necrotrophic Pathogen ◽  
Pathogen Effector

Manipulation of the host by pathogens to survive the lysosome

2010 ◽  
Vol 38 (6) ◽  
pp. 1417-1419 ◽  
Author(s):  
Paul R. Pryor ◽  
Sally A. Raines
Keyword(s):  
Innate Immunity ◽  
Membrane Trafficking ◽  
Molecular Mechanisms ◽  
Regulatory Elements ◽  
Effector Proteins ◽  
Intracellular Pathogens ◽  
Intracellular Environment ◽  
Pathogen Effector ◽  
Form Part ◽  
Survival Mechanisms

Lysosomes form part of our innate immunity and are an important line of defence against microbes, viruses and parasites. Although it is more than 50 years since de Duve discovered lysosomes, it is only in more recent years that we are slowly unravelling the molecular mechanisms involved in the delivery of material to the lysosome. However, successful intracellular pathogens often have a better grip on the mechanisms involved in delivery to the lysosome and can manipulate membrane trafficking pathways to create an intracellular environment that is favourable for replication. By studying pathogen effector proteins that are secreted into the host's cytosol, we can learn about both pathogen-survival mechanisms and further regulatory elements involved in trafficking to the lysosome.

The role of oomycete effectors in plant - pathogen interactions

2010 ◽  
Vol 37 (10) ◽  
pp. 919 ◽  
Author(s):  
Adrienne R. Hardham ◽  
David M. Cahill
Keyword(s):  
Plant Cell ◽  
Plant Pathogens ◽  
Plant Defence ◽  
Effector Proteins ◽  
Plant Structure ◽  
Cell Wall Degrading Enzymes ◽  
Cell Cytoplasm ◽  
Diverse Range ◽  
Successful Infection ◽  
Pathogen Effector

Plants constantly come into contact with a diverse range of microorganisms that are potential pathogens, and they have evolved multi-faceted physical and chemical strategies to inhibit pathogen ingress and establishment of disease. Microbes, however, have developed their own strategies to counteract plant defence responses. Recent research on plant–microbe interactions has revealed that an important part of the infection strategies of a diverse range of plant pathogens, including bacteria, fungi and oomycetes, is the production of effector proteins that are secreted by the pathogen and that promote successful infection by manipulating plant structure and metabolism, including interference in plant defence mechanisms. Pathogen effector proteins may function either in the extracellular spaces within plant tissues or within the plant cell cytoplasm. Extracellular effectors include cell wall degrading enzymes and inhibitors of plant enzymes that attack invading pathogens. Intracellular effectors move into the plant cell cytoplasm by as yet unknown mechanisms where, in incompatible interactions, they may be recognised by plant resistance proteins but where, in compatible interactions, they may suppress the plant’s immune response. This article presents a brief overview of our current understanding of the nature and function of effectors produced by oomycete plant pathogens.

scholarly journals Functional genomics and mycotoxin discovery in the wheat glume blotch pathogen Stagonospora nodorum

2011 ◽  
Vol 32 (4) ◽  
pp. 156
Author(s):  
Peter S Solomon
Keyword(s):  
Functional Genomics ◽  
Effector Proteins ◽  
Stagonospora Nodorum ◽  
Susceptibility Loci ◽  
Short Article ◽  
Cell Death Response ◽  
Glume Blotch ◽  
Pathogen Effector ◽  
Degradative Enzymes ◽  
Made In

Stagonospora nodorum is a fungal pathogen of wheat and is responsible for over $100 million in yield losses in Australia each year. Significant progress has recently been made in understanding how S. nodorum causes disease on wheat. These pathogens, known as a necrotrophs, were thought to secrete a battery of lytic and degradative enzymes during infection. These enzymes would simply degrade host tissue, allowing the infecting pathogen to feed off the lysed cellular contents. Recent studies have shown that this is not so, and that these fungi secrete unique effector proteins during the early stages of infection, which appear to be translocated into wheat cells. Once inside, these proteins interact (either directly or indirectly) with the products of dominant susceptibility loci leading to a localised programmed cell death response. Consequently, it is through an intricate gene-for-gene mechanism involving the interaction of pathogen effector proteins and host dominant susceptibility genes that S. nodorum infects its wheat host, not through a crude secretion of cell lysis enzymes. These findings have been recently reviewed by Oliver and Solomon3. This short article focuses on how modern functional genomics techniques have been exploited to reveal a new dimension to the wheat pathogen S. nodorum.

scholarly journals NAD+ cleavage activity by animal and plant TIR domains in cell death pathways

Science ◽  
2019 ◽  
Vol 365 (6455) ◽  
pp. 793-799 ◽  
Author(s):  
Shane Horsefield ◽  
Hayden Burdett ◽  
Xiaoxiao Zhang ◽  
Mohammad K. Manik ◽  
Yun Shi ◽  
...  
Keyword(s):  
Cell Death ◽  
Nicotinamide Adenine Dinucleotide ◽  
Interleukin 1 ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Effector Proteins ◽  
Nicotinamide Adenine ◽  
Cleavage Activity ◽  
Pathogen Effector ◽  
Cell Death Signaling ◽  
Tir Domains

SARM1 (sterile alpha and TIR motif containing 1) is responsible for depletion of nicotinamide adenine dinucleotide in its oxidized form (NAD+) during Wallerian degeneration associated with neuropathies. Plant nucleotide-binding leucine-rich repeat (NLR) immune receptors recognize pathogen effector proteins and trigger localized cell death to restrict pathogen infection. Both processes depend on closely related Toll/interleukin-1 receptor (TIR) domains in these proteins, which, as we show, feature self-association–dependent NAD+ cleavage activity associated with cell death signaling. We further show that SARM1 SAM (sterile alpha motif) domains form an octamer essential for axon degeneration that contributes to TIR domain enzymatic activity. The crystal structures of ribose and NADP+ (the oxidized form of nicotinamide adenine dinucleotide phosphate) complexes of SARM1 and plant NLR RUN1 TIR domains, respectively, reveal a conserved substrate binding site. NAD+ cleavage by TIR domains is therefore a conserved feature of animal and plant cell death signaling pathways.

scholarly journals Plant pathogen effector proteins as manipulators of host microbiomes?

2018 ◽  
Vol 19 (2) ◽  
pp. 257-259 ◽  
Author(s):  
Nick C. Snelders ◽  
Graeme J. Kettles ◽  
Jason J. Rudd ◽  
Bart P. H. J. Thomma
Keyword(s):  
Plant Pathogen ◽  
Effector Proteins ◽  
Pathogen Effector

scholarly journals The type III effector HopF2Pto targets Arabidopsis RIN4 protein to promote Pseudomonas syringae virulence

2010 ◽  
Vol 107 (5) ◽  
pp. 2349-2354 ◽  
Author(s):  
Mike Wilton ◽  
Rajagopal Subramaniam ◽  
James Elmore ◽  
Corinna Felsensteiner ◽  
Gitta Coaker ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Plant Immunity ◽  
Effector Proteins ◽  
Type Iii ◽  
Pathogen Effector ◽  
Effector Triggered Immunity ◽  
Type Iii Secretion Effector ◽  
Virulence Target

Plant immunity can be induced by two major classes of pathogen-associated molecules. Pathogen- or microbe-associated molecular patterns (PAMPs or MAMPs) are conserved molecular components of microbes that serve as “non-self” features to induce PAMP-triggered immunity (PTI). Pathogen effector proteins used to promote virulence can also be recognized as “non-self” features or induce a “modified-self” state that can induce effector-triggered immunity (ETI). The Arabidopsis protein RIN4 plays an important role in both branches of plant immunity. Three unrelated type III secretion effector (TTSE) proteins from the phytopathogen Pseudomonas syringae, AvrRpm1, AvrRpt2, and AvrB, target RIN4, resulting in ETI that effectively restricts pathogen growth. However, no pathogenic advantage has been demonstrated for RIN4 manipulation by these TTSEs. Here, we show that the TTSE HopF2Pto also targets Arabidopsis RIN4. Transgenic plants conditionally expressing HopF2Pto were compromised for AvrRpt2-induced RIN4 modification and associated ETI. HopF2Pto interfered with AvrRpt2-induced RIN4 modification in vitro but not with AvrRpt2 activation, suggestive of RIN4 targeting by HopF2Pto. In support of this hypothesis, HopF2Pto interacted with RIN4 in vitro and in vivo. Unlike AvrRpm1, AvrRpt2, and AvrB, HopF2Pto did not induce ETI and instead promoted P. syringae growth in Arabidopsis. This virulence activity was not observed in plants genetically lacking RIN4. These data provide evidence that RIN4 is a major virulence target of HopF2Pto and that a pathogenic advantage can be conveyed by TTSEs that target RIN4.

scholarly journals Accurate plant pathogen effector protein classification ab initio with deepredeff: an ensemble of convolutional neural networks

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ruth Kristianingsih ◽  
Dan MacLean
Keyword(s):  
Neural Networks ◽  
Deep Learning ◽  
Convolutional Neural Networks ◽  
Plant Pathogens ◽  
De Novo ◽  
Chemical Properties ◽  
Effector Proteins ◽  
Global Food Security ◽  
Pathogen Effector ◽  
Biological Insight

Abstract Background Plant pathogens cause billions of dollars of crop loss every year and are a major threat to global food security. Effector proteins are the tools such pathogens use to infect the cell, predicting effectors de novo from sequence is difficult because of the heterogeneity of the sequences. We hypothesised that deep learning classifiers based on Convolutional Neural Networks would be able to identify effectors and deliver new insights. Results We created a training set of manually curated effector sequences from PHI-Base and used these to train a range of model architectures for classifying bacteria, fungal and oomycete sequences. The best performing classifiers had accuracies from 93 to 84%. The models were tested against popular effector detection software on our own test data and data provided with those models. We observed better performance from our models. Specifically our models showed greater accuracy and lower tendencies to call false positives on a secreted protein negative test set and a greater generalisability. We used GRAD-CAM activation map analysis to identify the sequences that activated our CNN-LSTM models and found short but distinct N-terminal regions in each taxon that was indicative of effector sequences. No motifs could be observed in these regions but an analysis of amino acid types indicated differing patterns of enrichment and depletion that varied between taxa. Conclusions Small training sets can be used effectively to train highly accurate and sensitive deep learning models without need for the operator to know anything other than sequence and without arbitrary decisions made about what sequence features or physico-chemical properties are important. Biological insight on subsequences important for classification can be achieved by examining the activations in the model

scholarly journals Cell re-entry assays do not support models of pathogen- independent translocation of AvrM and AVR3a effectors into plant cells

2016 ◽  
Author(s):  
Benjamin Petre ◽  
Michaela Kopischke ◽  
Alexandre Evrard ◽  
Silke Robatzek ◽  
Sophien Kamoun
Keyword(s):  
Protein Trafficking ◽  
Fluorescent Proteins ◽  
Plant Cells ◽  
Effector Proteins ◽  
Effector Protein ◽  
Uptake Mechanism ◽  
Protein Uptake ◽  
Melampsora Lini ◽  
Pathogen Effector ◽  
Entry Assay

The cell re-entry assay is widely used to evaluate pathogen effector protein uptake into plant cells. The assay is based on the premise that effector proteins secreted out of a leaf cell would translocate back into the cytosol of the same cell via a yet unknown host-derived uptake mechanism. Here, we critically assess this assay by expressing domains of the effector proteins AvrM-A of Melampsora lini and AVR3a of Phytophthora infestans fused to a signal peptide and fluorescent proteins in Nicotiana benthamiana. We found that the secreted fusion proteins do not re-enter plant cells from the apoplast and that the assay is prone to false-positives. We therefore emit a cautionary note on the use of the cell re-entry assay for protein trafficking studies.

scholarly journals Fungal Induced Protein Hyperacetylation Identified by Acetylome Profiling

2016 ◽  
Author(s):  
Justin W Walley ◽  
Zhouxin Shen ◽  
Maxwell R. McReynolds ◽  
Steven P. Briggs
Keyword(s):  
Immune Response ◽  
Protein Function ◽  
Effector Proteins ◽  
Protein Acetylation ◽  
Post Translational Modification ◽  
Cochliobolus Carbonum ◽  
Pathogen Virulence ◽  
Pathogen Effector ◽  
Race 1 ◽  
Hc Toxin

ABSTRACTLysine acetylation is a key post-translational modification that regulates diverse proteins involved in a range of biological processes. The role of histone acetylation in plant defense is well established and it is known that pathogen effector proteins encoding acetyltransferses can directly acetylate host proteins to alter immunity. However, it is unclear whether endogenous plant enzymes can modulate protein acetylation during an immune response. Here we investigate how the effector molecule HC-toxin, a histone deacetylase inhibitor, produced by Cochliobolus carbonum race 1 promotes pathogen virulence in maize through altering protein acetylation. Using mass spectrometry we globally quantified the abundance of 3,636 proteins and the levels of acetylation at 2,791 sites in maize plants treated with HC-toxin as well as HC-toxin deficient or producing strains of C. carbonum. Analyses of these data demonstrate that acetylation is a widespread post-translational modification impacting proteins encoded by many intensively studied maize genes. Furthermore, the application of exogenous HC-toxin enabled us to show that the activity of plant-encoded enzymes can be modulated to alter acetylation of non-histone proteins during an immune response. Collectively, these results provide a resource for further mechanistic studies examining the regulation of protein function and offer insight into the complex immune response triggered by virulent C. carbonum.

scholarly journals Host–pathogen interactions and subversion of autophagy

2017 ◽  
Vol 61 (6) ◽  
pp. 687-697 ◽  
Author(s):  
David G. McEwan
Keyword(s):  
Host Cell ◽  
Amino Acid Starvation ◽  
Effector Proteins ◽  
Innate Immune ◽  
Complex Structures ◽  
Autophagy Gene ◽  
Pathogen Effector ◽  
Growth Factor Deprivation ◽  
Autophagy Pathway ◽  
Combating Infection

Macroautophagy (‘autophagy’), is the process by which cells can form a double-membraned vesicle that encapsulates material to be degraded by the lysosome. This can include complex structures such as damaged mitochondria, peroxisomes, protein aggregates and large swathes of cytoplasm that can not be processed efficiently by other means of degradation. Recycling of amino acids and lipids through autophagy allows the cell to form intracellular pools that aid survival during periods of stress, including growth factor deprivation, amino acid starvation or a depleted oxygen supply. One of the major functions of autophagy that has emerged over the last decade is its importance as a safeguard against infection. The ability of autophagy to selectively target intracellular pathogens for destruction is now regarded as a key aspect of the innate immune response. However, pathogens have evolved mechanisms to either evade or reconfigure the autophagy pathway for their own survival. Understanding how pathogens interact with and manipulate the host autophagy pathway will hopefully provide a basis for combating infection and increase our understanding of the role and regulation of autophagy. Herein, we will discuss how the host cell can identify and target invading pathogens and how pathogens have adapted in order to evade destruction by the host cell. In particular, we will focus on interactions between the mammalian autophagy gene 8 (ATG8) proteins and the host and pathogen effector proteins.

Sign in / Sign up

Export Citation Format

Share Document