scholarly journals Dynamic accumulation of a helper NLR at the plant-pathogen interface underpins pathogen recognition

2021 ◽  
Author(s):  
Cian Duggan ◽  
Eleonora Moratto ◽  
Zachary Savage ◽  
Eranthika Hamilton ◽  
Hiroaki Adachi ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Immune Responses ◽  
Subcellular Localization ◽  
Plant Pathogen ◽  
Coiled Coil ◽  
Dynamic Changes ◽  
Pathogen Effectors ◽  
Mediate Response ◽  
Potato Famine ◽  
Irish Potato Famine

Plants employ sensor-helper pairs of NLR immune receptors to recognize pathogen effectors and activate immune responses. Yet the subcellular localization of NLRs pre- and post- activation during pathogen infection remains poorly known. Here we show that NRC4, from the 'NRC' solanaceous helper NLR family, undergoes dynamic changes in subcellular localization by shuttling to and from the plant-pathogen haustorium interface established during infection by the Irish potato famine pathogen Phytophthora infestans. Specifically, prior to activation, NRC4 accumulates at the extra-haustorial membrane (EHM), presumably to mediate response to perihaustorial effectors, that are recognized by NRC4-dependent sensor NLRs. However not all NLRs accumulate at the EHM, as the closely related helper NRC2, and the distantly related ZAR1, did not accumulate at the EHM. NRC4 required an intact N- terminal coiled coil domain to accumulate at the EHM, whereas the functionally conserved MADA motif implicated in cell death activation and membrane insertion was dispensable for this process. Strikingly, a constitutively autoactive NRC4 mutant did not accumulate at the EHM and showed punctate distribution that mainly associated with the plasma membrane, suggesting that post-activation, NRC4 probably undergoes a conformation switch to form clusters that do not preferentially associate with the EHM. When NRC4 is activated by a sensor NLR during infection however, NRC4 formed puncta mainly at the EHM and to a lesser extent at the plasma membrane. We conclude that following activation at the EHM, NRC4 may spread to other cellular membranes from its primary site of activation to trigger immune responses.

scholarly journals Dynamic localization of a helper NLR at the plant–pathogen interface underpins pathogen recognition

2021 ◽  
Vol 118 (34) ◽  
pp. e2104997118 ◽  
Author(s):  
Cian Duggan ◽  
Eleonora Moratto ◽  
Zachary Savage ◽  
Eranthika Hamilton ◽  
Hiroaki Adachi ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Immune Responses ◽  
Subcellular Localization ◽  
Plant Pathogen ◽  
Coiled Coil ◽  
Dynamic Changes ◽  
Pathogen Effectors ◽  
Mediate Response ◽  
Potato Famine ◽  
Irish Potato Famine

Plants employ sensor–helper pairs of NLR immune receptors to recognize pathogen effectors and activate immune responses. Yet, the subcellular localization of NLRs pre- and postactivation during pathogen infection remains poorly understood. Here, we show that NRC4, from the “NRC” solanaceous helper NLR family, undergoes dynamic changes in subcellular localization by shuttling to and from the plant–pathogen haustorium interface established during infection by the Irish potato famine pathogen Phytophthora infestans. Specifically, prior to activation, NRC4 accumulates at the extrahaustorial membrane (EHM), presumably to mediate response to perihaustorial effectors that are recognized by NRC4-dependent sensor NLRs. However, not all NLRs accumulate at the EHM, as the closely related helper NRC2 and the distantly related ZAR1 did not accumulate at the EHM. NRC4 required an intact N-terminal coiled-coil domain to accumulate at the EHM, whereas the functionally conserved MADA motif implicated in cell death activation and membrane insertion was dispensable for this process. Strikingly, a constitutively autoactive NRC4 mutant did not accumulate at the EHM and showed punctate distribution that mainly associated with the plasma membrane, suggesting that postactivation, NRC4 may undergo a conformation switch to form clusters that do not preferentially associate with the EHM. When NRC4 is activated by a sensor NLR during infection, however, NRC4 forms puncta mainly at the EHM and, to a lesser extent, at the plasma membrane. We conclude that following activation at the EHM, NRC4 may spread to other cellular membranes from its primary site of activation to trigger immune responses.

scholarly journals The Plant Pathogen Phytophthora andina Emerged via Hybridization of an Unknown Phytophthora Species and the Irish Potato Famine Pathogen, P. infestans

PLoS ONE ◽  
2011 ◽  
Vol 6 (9) ◽  
pp. e24543 ◽  
Author(s):  
Erica M. Goss ◽  
Martha E. Cardenas ◽  
Kevin Myers ◽  
Gregory A. Forbes ◽  
William E. Fry ◽  
...  
Keyword(s):  
Plant Pathogen ◽  
Phytophthora Species ◽  
Irish Potato ◽  
Potato Famine ◽  
Irish Potato Famine

scholarly journals Chloroplasts navigate towards the pathogen interface to counteract infection by the Irish potato famine pathogen

2019 ◽  
Author(s):  
Alexia Toufexi ◽  
Cian Duggan ◽  
Pooja Pandey ◽  
Zachary Savage ◽  
María Eugenia Segretin ◽  
...  
Keyword(s):  
Immune Activation ◽  
Envelope Protein ◽  
Plant Cells ◽  
Irish Potato ◽  
Dependent Manner ◽  
Outer Envelope ◽  
Pathogen Effectors ◽  
Pathogen Entry ◽  
Potato Famine ◽  
Irish Potato Famine

AbstractChloroplasts are light harvesting organelles that arose from ancient endosymbiotic cyanobacteria. Upon immune activation, chloroplasts switch off photosynthesis, produce anti-microbial compounds, and develop tubular extensions called stromules. We report that chloroplasts navigate to the pathogen interface to counteract infection by the Irish potato famine pathogen Phytophthora infestans, physically associating with the specialised membrane that engulfs pathogen haustoria. Outer envelope protein, chloroplast unusual positioning1 (CHUP1), anchors chloroplasts to the host-pathogen interface. Stromules are induced during infection in a CHUP1-dependent manner, embracing haustoria and interconnecting chloroplasts, to form dynamic organelle clusters. Infection-triggered reprogramming of chloroplasts relies on surface immune signalling, whereas pathogen effectors subvert these immune pulses. Chloroplast are deployed focally, and coordinate to restrict pathogen entry into plant cells, a process actively countered by parasite effectors.

scholarly journals Host autophagosomes are diverted to a plant-pathogen interface

2017 ◽  
Author(s):  
Yasin F Dagdas ◽  
Pooja Pandey ◽  
Nattapong Sanguankiattichai ◽  
Yasin Tumtas ◽  
Khaoula Belhaj ◽  
...  
Keyword(s):  
Phytophthora Infestans ◽  
Plant Pathogen ◽  
Plant Pathogens ◽  
Irish Potato ◽  
Host Protein ◽  
Host Cells ◽  
Autophagosome Formation ◽  
Selective Autophagy ◽  
Potato Famine ◽  
Irish Potato Famine

AbstractFilamentous plant pathogens and symbionts invade their host cells but remain enveloped by host-derived membranes. The mechanisms underlying the biogenesis and functions of these host-microbe interfaces are poorly understood. Recently, we showed that PexRD54, an effector from the Irish potato famine pathogen Phytophthora infestans, binds host protein ATG8CL to stimulate autophagosome formation and deplete the selective autophagy receptor Joka2 from ATG8CL complexes. Here, we show that during P. infestans infection, ATG8CL autophagosomes are diverted to the pathogen interface. Our findings are consistent with the view that the pathogen coopts host selective autophagy for its own benefit.

scholarly journals Impact of Membrane Lipids on UapA and AzgA Transporter Subcellular Localization and Activity in Aspergillus nidulans

2021 ◽  
Vol 7 (7) ◽  
pp. 514
Author(s):  
Mariangela Dionysopoulou ◽  
George Diallinas
Keyword(s):  
Plasma Membrane ◽  
Subcellular Localization ◽  
Aspergillus Nidulans ◽  
Membrane Lipids ◽  
Membrane Lipid ◽  
Lipid Biosynthesis ◽  
Transport Kinetics ◽  
Negative Effect ◽  
And Function

Recent biochemical and biophysical evidence have established that membrane lipids, namely phospholipids, sphingolipids and sterols, are critical for the function of eukaryotic plasma membrane transporters. Here, we study the effect of selected membrane lipid biosynthesis mutations and of the ergosterol-related antifungal itraconazole on the subcellular localization, stability and transport kinetics of two well-studied purine transporters, UapA and AzgA, in Aspergillus nidulans. We show that genetic reduction in biosynthesis of ergosterol, sphingolipids or phosphoinositides arrest A. nidulans growth after germling formation, but solely blocks in early steps of ergosterol (Erg11) or sphingolipid (BasA) synthesis have a negative effect on plasma membrane (PM) localization and stability of transporters before growth arrest. Surprisingly, the fraction of UapA or AzgA that reaches the PM in lipid biosynthesis mutants is shown to conserve normal apparent transport kinetics. We further show that turnover of UapA, which is the transporter mostly sensitive to membrane lipid content modification, occurs during its trafficking and by enhanced endocytosis, and is partly dependent on autophagy and Hect-type HulARsp5 ubiquitination. Our results point out that the role of specific membrane lipids on transporter biogenesis and function in vivo is complex, combinatorial and transporter-dependent.

scholarly journals With an Ear up Against the Wall: An Update on Mechanoperception in Arabidopsis.

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1587
Author(s):  
Sara Behnami ◽  
Dario Bonetta
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Immune Responses ◽  
Mechanical Stress ◽  
Mechanosensitive Channels ◽  
Compensatory Responses ◽  
Cell Wall Damage ◽  
Mechanical Signals ◽  
Hormone Signalling

Cells interpret mechanical signals and adjust their physiology or development appropriately. In plants, the interface with the outside world is the cell wall, a structure that forms a continuum with the plasma membrane and the cytoskeleton. Mechanical stress from cell wall damage or deformation is interpreted to elicit compensatory responses, hormone signalling, or immune responses. Our understanding of how this is achieved is still evolving; however, we can refer to examples from animals and yeast where more of the details have been worked out. Here, we provide an update on this changing story with a focus on candidate mechanosensitive channels and plasma membrane-localized receptors.

scholarly journals Perturbation of host autophagy by the Irish potato famine pathogen

2014 ◽  
Vol 70 (a1) ◽  
pp. C826-C826
Author(s):  
Abbas Maqbool ◽  
Richard Richard ◽  
Tolga Bozkurt ◽  
Yasin Dagdas ◽  
Khaoula Belhai ◽  
...  
Keyword(s):  
Host Cell ◽  
Plant Cells ◽  
Irish Potato ◽  
Effector Proteins ◽  
Host Cells ◽  
Cell Physiology ◽  
Biochemical Basis ◽  
The Impact ◽  
Potato Famine ◽  
Irish Potato Famine

Autophagy is a catabolic process involving degradation of dysfunctional cytoplasmic components to ensure cellular survival under starvation conditions. The process involves formation of double-membrane vesicles called autophagosomes and delivery of the inner constituents to lytic compartments. It can also target invading pathogens, such as intracellular bacteria, for destruction and is thus implicated in innate immune pathways [1]. In response, certain mammalian pathogens deliver effector proteins into host cells that inhibit autophagy and contribute to enabling parasitic infection [2]. Pyhtophthora infestans, the Irish potato famine pathogen, is a causative agent of late blight disease in potato and tomato crops. It delivers a plethora of modular effector proteins into plant cells to promote infection. Once inside the cell, RXLR-type effector proteins engage with host cell proteins, to manipulate host cell physiology for the benefit of the pathogen. As plants lack an adaptive immune system, this provides a robust mechanism for pathogens to circumvent host defense. PexRD54 is an intracellular RXLR-type effector protein produced by P. infestans. PexRD54 interacts with potato homologues of autophagy protein ATG8 in plant cells. We have been investigating the structural and biochemical basis of the PexRD54/ATG8 interaction in vitro. We have purified PexRD54 and ATG8 independently and in complex from E. coli. Using protein/protein interaction studies we have shown that PexRD54 binds ATG8 with sub-micromolar affinity. We have also determined the structure of PexRD54 in the presence of ATG8. This crystal structure provides key insights into how the previously reported WY-fold of oomycete RXLR-type effectors [3] can be organized in multiple repeats. The structural data also provides insights into the interaction between PexRD54 and ATG8, suggesting further experiments to understand the impact of this interaction on host cell physiology and how this benefits the pathogen.

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