Search results for "Fungal Proteins"
showing 10 items of 225 documents
The chaperone-like protein Cdc48 regulates ubiquitin-proteasome system in plants.
2021
The degradation of misfolded proteins is mainly mediated by the ubiquitin-proteasome system (UPS). UPS can be assisted by the protein Cdc48 but the relationship between UPS and Cdc48 in plants has been poorly investigated. Here, we analyzed the regulation of UPS by Cdc48 in tobacco thanks to two independent cell lines overexpressing Cdc48 constitutively and plant leaves overexpressing Cdc48 transiently. In the cell lines, the accumulation of ubiquitinated proteins was affected both quantitatively and qualitatively and the amount of proteasomal subunits was modified, while proteolytic activities were unchanged. Similarly, the over-expression of Cdc48 in planta impacted the accumulation of ub…
Functional characterization of the chaperon-like protein Cdc48 in cryptogein-induced immune response in tobacco
2017
SPEIPMUBINRASUPDATDOCT; Cdc48, a molecular chaperone conserved in different kingdoms, is a member of the AAA+ family contributing to numerous processes in mammals including proteins quality control and degradation, vesicular trafficking, autophagy and immunity. The functions of Cdc48 plant orthologues are less understood. We previously reported that Cdc48 is regulated by S-nitrosylation in tobacco cells undergoing an immune response triggered by cryptogein, an elicitin produced by the oomycete Phytophthora cryptogea. Here, we inv estigated the function of NtCdc48 in cryptogein signalling and induced hypersensitive-like cell death. NtCdc48 was found to accumulate in elicited cells at both th…
Sugar exchanges in arbuscular mycorrhiza: RiMST5 and RiMST6, two novel Rhizophagus irregularis monosaccharide transporters, are involved in both suga…
2016
SPE IPM INRA UB CT1; International audience; Arbuscular mycorrhizal (AM) fungi are associated with about 80% of land plants. AM fungi provide inorganic nutrients to plants and in return up to 20% of the plant-fixed CO2 is transferred to the fungal symbionts. Since AM fungi are obligate biotrophs, unraveling how sugars are provided to the fungus partner is a key for understanding the functioning of the symbiosis. In this study, we identified two new monosaccharide transporters from Rhizophagus irregularis (RiMST5 and RiMST6) that we characterized as functional high affinity monosaccharide transporters. RiMST6 was characterized as a glucose specific, high affinity H(+) co-transporter. We prov…
Constitutive expression of clathrin hub hinders elicitor-induced clathrin-mediated endocytosis and defense gene expression in plant cells.
2012
International audience; Endocytosis has been recently implicated in the signaling network associated with the recognition of microbes by plants. In a previous study, we showed that the elicitor cryptogein was able to induce clathrin-mediated endocytosis (CME) in tobacco suspension cells. Herein, we investigate further the induced CME by means of a GFP-tagged clathrin light chain and a CME inhibitor, the hub domain of clathrin heavy chain. Hub constitutive expression does affect neither cell growth nor constitutive endocytosis but abolishes cryptogein-induced CME. Such an inhibition has no impact on early events in the cryptogein signaling pathway but reduces the expression of defense-associ…
Involvement of plasma membrane proteins in plant defense responses. Analysis of the cryptogein signal transduction in tobacco
1999
International audience; Cryptogein, a 98 amino acid protein secreted by the fungus Phytophthora cryptogea, induces a hypersensitive response and systemic acquired resistance in tobacco plants (Nicotiana tabacum var Xanthi). The mode of action of cryptogein has been studied using tobacco cell suspensions. The recognition of this elicitor by a plasma membrane receptor leads to a cascade of events including protein phosphorylation, calcium influx, potassium and chloride effluxes, plasma membrane depolarization, activation of a NADPH oxidase responsible for active oxygen species (AOS) production and cytosol acidification, activation of the pentose phosphate pathway, and activation of two mitoge…
Tobacco cells contain a protein, immunologically related to the neutrophil small G protein Rac2 and involved in elicitor-induced oxidative burst.
1997
Abstract Suspension-cultured cells of Nicotiana tabacum generated active oxygen species (AOS) when they were treated with the proteinaceous elicitor, cryptogein. This response was blocked by diphenylene iodonium, an inhibitor of the neutrophil NADPH oxidase. When microsomal extracts of tobacco cells were probed with an antibody directed against the human small G protein Rac2, two immunoreactive proteins were detected at 18.5 and 20.5 kDa. The same experiment performed with cytosolic extracts of tobacco cells led to the observation of a strong immunoreactive protein at 21.5 kDa only in the cryptogein-treated cells. The appearance of this cytosolic protein was related to the production of AOS…
Type-2 histone deacetylases as new regulators of elicitor-induced cell death in plants
2011
voir Addenda, notes additionnelles complétant l'article : "Dahan, J., Hammoudi, V., Wendehenne, D., Bourque, S. (2011). Type 2 histone deacetylases play a major role in the control of elicitor-induced cell death in tobacco. Plant signaling & behavior, 6 (11), 1865-1867. DOI : 10.4161/psb.6.11.17848".; International audience; Plant resistance to pathogen attack is often associated with a localized programmed cell death called hypersensitive response (HR). How this cell death is controlled remains largely unknown. Upon treatment with cryptogein, an elicitor of tobacco defence and cell death, we identified NtHD2a and NtHD2b, two redundant isoforms of type-2 nuclear histone deacetylases (HDACs…
Preferential induction of 20S proteasome subunits during elicitation of plant defense reactions: towards the characterization of "plant defense prote…
2003
Plants have evolved efficient mechanisms to resist pathogens. The earliest defense response is the hypersensitive response (HR) considered as the main step leading to plant systemic acquired resistance (SAR) that protects the whole plant against a large spectrum of pathogens. We showed previously that elicitation of defense reactions in tobacco cells by cryptogein, a proteinaceous elicitor of plant defense reactions, leads to a rapid and differential accumulation of transcripts corresponding to genes encoding defense-induced (din) subunits of 20S proteasome: beta1din, alpha3din and alpha6din.Here, expression of these three subunits was investigated by Northern blotting and by Western blotti…
Involvement of putative glutamate receptors in plant defence signaling and NO production
2011
International audience; Ionotropic glutamate receptors (iGluRs) are non-selective cation channels permeable to calcium, present in animals and plants. In mammals, glutamate is a well-known neurotransmitter and recently has been recognized as an immunomodulator. As animals and plants share common mechanisms that govern innate immunity with calcium playing a key role in plant defence activation, we have checked the involvement of putative iGluRs in plant defence signaling. Using tobacco cells, we first provide evidence supporting the activity of iGluRs as calcium channels and their involvement in NO production as reported in animals. Thereafter, iGluRs were shown to be activated in response t…
Protein actors sustaining arbuscular mycorrhizal symbiosis: underground artists break the silence
2013
'Summary' 26 I. 'Casting for a scenario' 26 II. 'Nominees for a preliminary role' 27 III. 'Nominees for a leading role' 32 IV. 'Future artists' 37 'Acknowledgements' 38 References 38 Summary The roots of most land plants can enter a relationship with soil-borne fungi belonging to the phylum Glomeromycota. This symbiosis with arbuscular mycorrhizal (AM) fungi belongs to the so-called biotrophic interactions, involving the intracellular accommodation of a microorganism by a living plant cell without causing the death of the host. Although profiling technologies have generated an increasing depository of plant and fungal proteins eligible for sustaining AM accommodation and functioning, a …