Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Ralstonia solanacearum core effector RipE1 interacts and cleaves the Arabidopsis exocyst component Exo70B1

ABSTRACT: Ralstonia solanacearum depends on numerous virulence factors, also known as effectors, to promote disease in a wide range of economically important host-plants. Although some of these effectors have been characterized, none has been shown to target the host’s secretion machinery so far. Here, a screening was performed, using an extended library of NLR plant immune receptors’ integrated domains (IDs), to identify new effector targets. The results uncovered that the core effector RipE1, of the R. solanacearum species complex, among other targets, associates with Arabidopsis exocyst component Exo70B1. RipE1, in accordance with its predicted cysteine protease activity, cleaves Exo70B1 in vitro between its sequence and is able to promote Exo70B1 degradation in planta. RipE1 enzymatic activity additionally results in the activation of TN2-dependent cell death. TN2 is an atypical NLR that has been proposed to guard Exo70B1. Despite the fact that RipE1 has been previously reported to activate defense responses in model plant species, we present here a Nicotiana species, in which RipE1 expression does not activate cell death. Overall, this study uncovers a new RipE1 host target, while providing evidence and novel tools to advance in-depth studies of RipE1 and homologues effectors.

INSTRUMENT(S):

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

SUBMITTER: Nikos Kountourakis

LAB HEAD: Panagiotis F. Sarris

PROVIDER: PXD041406 | Pride | 2025-04-07

REPOSITORIES: Pride

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
	RipE1_C172A_mutant_Exo70B1_cleavage_assay_01.dat	Other
	RipE1_C172A_mutant_Exo70B1_cleavage_assay_01.raw	Raw
	RipE1_C172A_mutant_Exo70B1_cleavage_assay_02.dat	Other
	RipE1_C172A_mutant_Exo70B1_cleavage_assay_02.raw	Raw
	RipE1_C172A_mutant_Exo70B1_cleavage_assay_03.dat	Other

Items per page:

1 - 5 of 17

Similar Datasets

The functional and structural characterization of Xanthomonas campestris pv. campestris core effector XopP revealed a new kinase activity

Project description:The exocyst complex subunit protein Exo70B1 plays a crucial role in a variety of cell mechanisms including immune responses against pathogens. The calcium dependent kinase 5 (CPK5) of Arabidopsis thaliana, phosphorylates AtExo70B1 upon functional disruption. We previously reported that, the Xanthomonas campestris pv. campestris effector XopP, compromises AtExo70B1 and bypasses the host’s hypersensitive response (HR), in a way that is still unclear. Herein we designed an experimental approach based on biophysical, biochemical and molecular assays, based on structural and functional predictions, as well as, utilizing Aplhafold and DALI online servers respectively, in order to characterize the in vivo XccXopP function. The interaction between AtExo70B1 and XccXopP is very stable in high temperatures, while the AtExo70B1 appeared to be phosphorylated at XccXopP expressing transgenic Arabidopsis. XccXopP reveals similarities with known mammalian kinases, and phosphorylates AtExo70B1 at Ser107, Ser111, Ser248, Thr309 and Thr364. Moreover, XccXopP protects AtExo70B1 from AtCPK5 phosphorylation. Together these findings show that, XccXopP is an effector, which not only functions as a novel serine/threonine kinase upon its host’s protein target AtExo70B1, but also protects the latter from the innate AtCPK5 phosphorylation, to bypass the host’s immune responses.

2023-06-26 | PXD041405 | Pride

Time-course RNA-seq analysis of the barley MLA1 immune receptor-mediated response to barley powdery mildew fungus Bgh in Arabidopsis thaliana

Project description:We report that an intracellular NLR immune receptor from monocotyledonous barley is fully functional in dicotyledonous Arabidopsis thaliana. In contrast to common belief in plant NLR biology, this implies ~150 million years of evolutionary conservation of the underlying immune mechanism. This also suggests a conserved translocation mechanism for pathogen effectors in flowering plants. The deduced connectivity of the NLR to bifurcated signaling pathways likely confers increased robustness against pathogen interception, which could have contributed to the evolutionary preservation of the immune mechanism. RNA-seq experiments in Arabidopsis detected sustained expression of a single major MLA1-dependent gene cluster. 3 biological replicates per condition. The Arabidopsis plants without (pps) or with (B12) the MLA1-HA construct in a pen2 pad4 sag101 background were challenged with either the Bgh isolate K1 expressing the cognate AVRA1 effector for MLA1 or the Bgh isolate A6 expressing other AVRA effectors. Samples were collected at 6, 12, 18, 24 hours post inoculation (hpi) of Bgh.

2012-11-22 | E-GEOD-39463 | biostudies-arrayexpress

Acetylation of ARID proteins by Ralstonia solanacearum effector PopP2 in plants

Project description:Like many gram-negative phytopathogenic bacteria, Ralstonia solanacearum uses a type III secretion system to deliver into host cells a cocktail of effector proteins that can interfere with plant defences and promote infection. One of these effectors, the nuclear-targeted PopP2 acetyltransferase, was reported to inhibit many defensive WRKY transcription factors through acetylation. To gain a better understanding of the mechanisms by which PopP2 might exert its virulence functions, we searched for other PopP2-interacting partners. Here we report the identification of the Arabidopsis thaliana AT-Rich Interaction Domain protein 3 (ARID3) and its close homologs, ARID2 and ARID4 as additional targets of PopP2.

2025-05-06 | PXD055620 | Pride

Protein-protein interaction of Phytophthora infestans RxLR effector AvrCap1 by immunoafinity enrichment in planta

Project description:In plants, NLR (nucleotide-binding domain and leucine-rich repeat-containing) proteins can form receptor networks to confer hypersensitive cell death and innate immunity. One class of NLRs, known as NRCs (NLR required for cell death), are central nodes in a complex network that protects against multiple pathogens and comprises up to half of the NLRome of solanaceous plants. Given the prevalence of this NLR network, we hypothesized that pathogens convergently evolved to secrete effectors that target NRC activities. To test this, we screened a library of 167 bacterial, oomycete, nematode and aphid effectors for their capacity to suppress the cell death response triggered by the NRC-dependent disease resistance proteins Prf and Rpi-blb2. Among five of the identified suppressors, one cyst nematode protein and one oomycete protein suppress the activity of autoimmune mutants of NRC2 and NRC3, but not NRC4, indicating that they specifically counteract a subset of NRC proteins independently of their sensor NLR partners. Whereas the cyst nematode effector SPRYSEC15 binds the nucleotide-binding domain of NRC2 and NRC3, the oomycete effector AVRcap1b suppresses the response of these NRCs via the membrane trafficking-associated protein NbTOL9a (Target of Myb 1-like protein 9a). The interaction was studied by co-immunoprecipitation in plantacoupled with tandem mass spectrometry (IP-MS).

2021-03-03 | PXD023178 | Pride

RNA-seq analysis of Ralstonia solanacearum treated with nitrosative and oxidative stress

Project description:Ralstonia solancearum causes bacterial wilt disease on diverse plant hosts. R. solanacearum cells enter a host from soil or infested water through the roots, then multiply and spread in the water-transporting xylem vessels. Despite the low nutrient content of xylem sap, R. solanacearum grows extremely well inside the host, using denitrification to respire in this hypoxic environment. R. solanacearum growth in planta also depends on the successful deployment of protein effectors into host cells using a Type III Secretion System (T3SS). The T3SS is absolutely required for R. solanacearum virulence, but it is metabolically costly and can trigger host defenses. Thus, the pathogen’s success depends on optimized regulation of the T3SS. We found that a byproduct of denitrification, the toxic free-radical nitric oxide (NO), positively regulates the R. solanacearum T3SS both in vitro and in planta. Using chemical treatments and R. solanacearum mutants with altered NO levels, we show that the expression of a key T3SS regulator is induced by NO in culture. Analyzing the transcriptome of R. solanacearum responding to varying levels of NO both in culture and in planta revealed that the T3SS and effectors were broadly upregulated with increasing levels of NO. This regulation was specific to the T3SS and was not shared by other stressors. Our results suggest that R. solanacearum experiences an NO-rich environment in the plant host and may use this NO as a signal to activate T3SS during infection.

2020-10-26 | GSE160024 | GEO

Transition metal-triggered immunity via an Arabidopsis NLR pair

Project description:Plants growing in soil are challenged by multiple biotic (e.g. pathogens) and abiotic (e.g. heavy metals) stressors. Stress resistance is a key determinant for plants to thrive in the environment. Resistance to pathogens requires innate immunity , whereas tolerance to metal ions is accomplished by mechanisms such as complexation and compartmentation. Some transition metals can enhance plant’s defense against pathogens4,5, but the mechanism remains unclear. Here, we show that an Arabidopsis head-to-head gene pair of intracellular nucleotide-binding leucine-rich repeat (NLR) receptors antagonistically control transition metal-triggered immunity. One NLR, STM2 directly perceives transition metal ions, such as Cd2+, Cu2+ and Zn2+, as a ligand to activate its NAD+ hydrolytic activity and immune responses, triggering enhanced resistance to the soil-borne bacterial wilt pathogen Ralstonia solanacearum. The other NLR, STM1 suppresses STM2 to protect plants from transition metal-triggered immunity and growth inhibition in the presence of excess metals. STM1 also dampens resistance to the pathogen. Our study defines an NLR activated by transition metals and reveals a trade-off between resistance to pathogens and tolerance to transition metals that are pervasive in soil.

2025-03-11 | GSE291226 | GEO

Transition metal-triggered immunity via an Arabidopsis NLR pair

Project description:Plants growing in soil are challenged by multiple biotic (e.g. pathogens) and abiotic (e.g. heavy metals) stressors. Stress resistance is a key determinant for plants to thrive in the environment. Resistance to pathogens requires innate immunity 1, whereas tolerance to metal ions is accomplished by mechanisms such as complexation and compartmentation2,3. Some transition metals can enhance plant’s defense against pathogens4,5, but the mechanism remains unclear. Here, we show that an Arabidopsis head-to-head gene pair of intracellular nucleotide-binding leucine-rich repeat (NLR) receptors antagonistically control transition metal-triggered immunity. One NLR, STM2 directly perceives transition metal ions, such as Cd2+, Cu2+ and Zn2+, as a ligand to activate its NAD+ hydrolytic activity and immune responses, triggering enhanced resistance to the soil-borne bacterial wilt pathogen Ralstonia solanacearum. The other NLR, STM1 suppresses STM2 to protect plants from transition metal-triggered immunity and growth inhibition in the presence of excess metals. STM1 also dampens resistance to the pathogen. Our study defines an NLR activated by transition metals and reveals a trade-off between resistance to pathogens and tolerance to transition metals that are pervasive in soil.

2025-03-10 | GSE291114 | GEO

Time-course RNA-seq analysis of the barley MLA1 immune receptor-mediated response to barley powdery mildew fungus Bgh in Arabidopsis thaliana

2012-11-22 | GSE39463 | GEO

An in-depth Mass Spectrometry Characterization of the SDS-PAGE Protein Profile of Legumins and Vicilins from Chickpea Seed

Project description:Chickpea (Cicer arietinum L.) seed proteins show a lot of functional properties leading this leg-ume an interesting component for the development of protein-enriched foods. However, both in-depth proteomic investigation and structural characterization of chickpea proteins seed are still lacking. In this paper we report a detailed characterization of chickpea seed protein fraction by means SDS-PAGE, in-gel protein digestion, high-resolution mass spectrometry, and database searching. By this approach twenty SDS gel bands were cut and analysed. While the majority of bands and the identified peptides were related to vicilin and legumin storage proteins, also metabolic functional proteins were detected. Legumins, as expected, were revealed at 45÷65 kDa, as whole subunits with the α- and β-chains linked together by a disulphide bond, but also at lower mass ranges (α- and β-chains migrating alone). Similarly, but not expected, also the vi-cilins were spread along the mass region between 65 and 23 kDa, with some of them identified in several bands. In-depth MS structural characterization allowed to determine that, although chickpea vicilins were always described as proteins lacking of cysteine residues, they contain this amino acid residue. Moreover, similarly to legumins, these storage proteins are firstly syn-thesized as pre-propolypeptides (Mr 50÷80 kDa), that may undergo to proteolytic steps that cut not only the signal peptides but also produce different subunits having lower molecular masses. Overall, about 360 different proteins specific of the Cicer arietinum L. species were identified and characterized, a result that up to date represents the most detailed description of seed’s proteome of this legume.

2024-06-23 | PXD049382 | Pride

Bacterial host adaptation through sequence and structural variations of a single type III effector gene

Project description:Molecular mechanisms underlying quantitative variations of pathogenicity remain elusive. Here, we identified the Xanthomonas campestris XopJ6 effector that triggers disease resistance in cauliflower and Arabidopsis thaliana. XopJ6 is a close homolog of the Ralstonia solanacearum PopP2 YopJ family acetyltransferase. XopJ6 is recognized by the RRS1-R/RPS4 NLR pair that integrates a WRKY decoy domain mimicking effector true targets. We identified a XopJ6 natural variant carrying a single residue substitution in XopJ6 WRKY-binding site that disrupts interaction with WRKY proteins. This mutation allows XopJ6 to evade immune perception while retaining XopJ6 virulence functions. Interestingly, xopJ6 resides in a Tn3-family transposon likely contributing to xopJ6 copy number variation (CNV). Using genetic complementation assays, we demonstrate that xopJ6 CNV allows fine-tuning of pathogen virulence on Arabidopsis through gene dosage-mediated modulation of xopJ6 expression. Together, our findings highlight how sequence and structural genetic variations restricted at a particular effector gene contribute to bacterial host adaptation.

2024-01-29 | PXD038104 | Pride

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data