Maize nicotinate N-methyltransferase interacts with the NLR protein Rp1-D21 and modulates the hypersensitive response.
Ontology highlight
ABSTRACT:
SUBMITTER: Liu M
PROVIDER: S-EPMC8035639 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Nucleotide binding, leucine-rich-repeat (NLR) proteins are the major class of resistance (R) proteins used by plants to defend against pathogen infection. The recognition between NLRs and their cognate pathogen effectors usually triggers a rapid localized cell death, termed the hypersensitive response (HR). Flavone synthase I (FNSI) is one of the key enzymes in the flavone biosynthesis pathway. It also displays salicylic acid (SA) 5-hydroxylase (S5H) activity. A close homolog of FNSI/S5H displays SA 3-hydroxylase (S3H) activity. Both FNSI/S5H and S3H play important roles in plant innate immunity. However, the underlying molecular mechanisms and the relationship between S5H and S3H with the NLR-mediated HR are not known in any plant species. In this study, we identified three genes encoding ZmFNSI-1, ZmFNSI-2 and ZmS3H that are significantly upregulated in a maize line carrying an autoactive NLR Rp1-D21 mutant. Functional analysis showed that ZmFNSI-1 and ZmFNSI-2, but not ZmS3H, suppressed HR conferred by Rp1-D21 and its signaling domain CCD21 when transiently expressed in N. benthamiana. ZmFNSI-1 and ZmFNSI-2 physically interacted with CCD21. Furthermore, ZmFNSI-1 and ZmFNSI-2 interacted with HCT, a key enzyme in lignin biosynthesis pathway, which can also suppress Rp1-D21-mediated HR. These results lay the foundation for the further functional analysis of the roles of FNSI in plant innate immunity.
| S-EPMC7177559 | biostudies-literature
Project description:Protein arginine methyltransferases (PRMTs) are enzymes that regulate the evolutionarily conserved process of arginine methylation. It has been reported that PRMTs are involved in many metabolic regulatory pathways. However, until now, their roles in adipocyte function, especially browning and thermogenesis, have not been evaluated. Even though Prmt1 adipocyte-specific-deleted mice (Prmt1fl/flAQcre) appeared normal at basal level, following cold exposure or ?-adrenergic stimulation, impaired induction of the thermogenic program was observed in both the interscapular brown adipose tissue and inguinal white adipose tissue of Prmt1fl/flAQcre mice compared with littermate controls. Different splicing variants of Prmt1 have been reported. Among them, PRMT1 variant 1 and PRMT1 variant 2 (PRMT1V2) are well conserved between humans and mice. Both variants contribute to the activation of thermogenic fat, with PRMT1V2 playing a more dominant role. Mechanistic studies using cultured murine and human adipocytes revealed that PRMT1V2 mediates thermogenic fat activation through PGC1?, a transcriptional coactivator that has been shown to play a key role in mitochondrial biogenesis. To our knowledge, our data are the first to demonstrate that PRMT1 plays a regulatory role in thermogenic fat function. These findings suggest that modulating PRMT1 activity may represent new avenues to regulate thermogenic fat and mediate energy homeostasis. This function is conserved in human primary adipocytes, suggesting that further investigation of this pathway may ultimately lead to therapeutic strategies against human obesity and associated metabolic disorders.
| S-EPMC6853686 | biostudies-literature
Project description:'Candidatus Liberibacter asiaticus' (CLas) is a bacterium that causes Huanglongbing, also known as citrus greening, in citrus plants. 'Candidatus Liberibacter solanacearum' (Lso) is a close relative of CLas and in the US it infects solanaceous crops, causing zebra chip disease in potato. Previously, we have identified the Lso hypothetical protein effector 1 (Lso-HPE1). This protein uses a signal peptide for secretion; disrupts programmed cell death; and interacts with tomato RAD23c, d, and e proteins, but not with RAD23a. In this study, we evaluated whether CLIBASIA_00460, the CLas homolog of Lso-HPE1 interacted with citrus RAD23 proteins and disrupted their programmed cell death. Based on the yeast two-hybrid assay results, CLIBASIA_00460 interacted with citrus RAD23c and RAD23d, but not with citrus RAD23b. These results were confirmed using bimolecular fluorescence complementation assays, which showed that these interactions occurred in cell puncta, but not in the nucleus or cytoplasm. Additionally, CLIBASIA_00460 was able to disrupt the PrfD1416V-induced hypersensitive response. Therefore, based on the similar interactions between Lso-HPE1 and CLIBASIA_00460 with the host RAD23 proteins and their ability to inhibit cell death in plants, we propose that these effectors may have similar functions during plant infection.
| S-EPMC9324546 | biostudies-literature
Project description:Cell surface pattern recognition receptors (PRRs) activate immune responses that can include the hypersensitive cell death. However, the pathways that link PRRs to the cell death response are poorly understood. Here, we show that the cell surface receptor-like protein Cf-4 requires the intracellular nucleotide-binding domain leucine-rich repeat containing receptor (NLR) NRC3 to trigger a confluent cell death response upon detection of the fungal effector Avr4 in leaves of Nicotiana benthamiana. This NRC3 activity requires an intact N-terminal MADA motif, a conserved signature of coiled-coil (CC)-type plant NLRs that is required for resistosome-mediated immune responses. A chimeric protein with the N-terminal α1 helix of Arabidopsis ZAR1 swapped into NRC3 retains the capacity to mediate Cf-4 hypersensitive cell death. Pathogen effectors acting as suppressors of NRC3 can suppress Cf-4-triggered hypersensitive cell-death. Our findings link the NLR resistosome model to the hypersensitive cell death caused by a cell surface PRR.
| S-EPMC9543701 | biostudies-literature
Project description:Rp1 is a complex rust resistance locus of maize. The HRp1-D haplotype is composed of Rp1-D and eight paralogues, seven of which also code for predicted nucleotide binding site-leucine rich repeat (NBS-LRR) proteins similar to the Rp1-D gene. The paralogues are polymorphic (DNA identities 91-97%), especially in the C-terminal LRR domain. The remaining family member encodes a truncated protein that has no LRR domain. Seven of the nine family members, including the truncated gene, are transcribed. Sequence comparisons between paralogues provide evidence for past recombination events between paralogues and diversifying selection, particularly in the C-terminal half of the LRR domain. Variants selected for complete or partial loss of Rp1-D resistance can be explained by unequal crossing over that occurred mostly within coding regions. The Rp1-D gene is altered or lost in all variants, the recombination breakpoints occur throughout the genes, and most recombinant events (9/14 examined) involved the same untranscribed paralogue with the Rp1-D gene. One recombinant with a complete LRR from Rp1-D, but the amino-terminal portion from another homologue, conferred the Rp1-D specificity but with a reduced level of resistance.
| S-EPMC1461629 | biostudies-other
Project description:The flaviviral nonstructural protein 5 (NS5) is a phosphoprotein, though the precise identities and roles of many specific phosphorylations remain unknown. Protein kinase G (PKG), a cGMP-dependent protein kinase, has previously been shown to phosphorylate dengue virus NS5.We used mass spectrometry to specifically identify NS5 phosphosites. Co-immunoprecipitation assays were used to study protein-protein interactions. Effects on viral replication were measured via replicon system and plaque assay titering.We identified multiple sites in West Nile virus (WNV) NS5 that are phosphorylated during a WNV infection, and showed that the N-terminal methyltransferase domain of WNV NS5 can be specifically phosphorylated by PKG in vitro. Expressing PKG in cell culture led to an enhancement of WNV viral production. We hypothesized this effect on replication could be caused by factors beyond the specific phosphorylations of NS5. Here we show for the first time that PKG is also able to stably interact with a viral substrate, WNV NS5, in cell culture and in vitro. While the mosquito-borne WNV NS5 interacted with PKG, tick-borne Langat virus NS5 did not. The methyltransferase domain of NS5 is able to mediate the interaction between NS5 and PKG, and mutating positive residues in the ?E region of the methyltransferase interrupts the interaction. These same mutations completely inhibited WNV replication.PKG is not required for WNV replication, but does make a stable interaction with NS5. While the consequence of the NS5:PKG interaction when it occurs is unclear, mutational data demonstrates that this interaction occurs in a region of NS5 that is otherwise necessary for replication. Overall, the results identify an interaction between virus and a cellular kinase and suggest a role for a host kinase in enhancing flaviviral replication.
| S-EPMC3725163 | biostudies-literature
Project description:The NRC immune receptor network has evolved in asterid plants from a pair of linked genes into a genetically dispersed and phylogenetically structured network of sensor and helper NLR (nucleotide-binding domain and leucine-rich repeat-containing) proteins. In some species, such as the model plant Nicotiana benthamiana and other Solanaceae, the NRC (NLR-REQUIRED FOR CELL DEATH) network forms up to half of the NLRome, and NRCs are scattered throughout the genome in gene clusters of varying complexities. Here, we describe NRCX, an atypical member of the NRC family that lacks canonical features of these NLR helper proteins, such as a functional N-terminal MADA motif and the capacity to trigger autoimmunity. In contrast to other NRCs, systemic gene silencing of NRCX in N. benthamiana markedly impairs plant growth resulting in a dwarf phenotype. Remarkably, dwarfism of NRCX silenced plants is partially dependent on NRCX paralogs NRC2 and NRC3, but not NRC4. Despite its negative impact on plant growth when silenced systemically, spot gene silencing of NRCX in mature N. benthamiana leaves doesn't result in visible cell death phenotypes. However, alteration of NRCX expression modulates the hypersensitive response mediated by NRC2 and NRC3 in a manner consistent with a negative role for NRCX in the NRC network. We conclude that NRCX is an atypical member of the NRC network that has evolved to contribute to the homeostasis of this genetically unlinked NLR network.
| S-EPMC9851556 | biostudies-literature
Project description:The maize Rp1 rust resistance locus is a complex consisting of a family of closely related resistance genes. The number of Rp1 paralogs in different maize lines (haplotypes) varied from a single gene in some stocks of the inbred A188 to >50 genes in haplotypes carrying the Rp1-A and Rp1-H specificities. The sequences of paralogs in unrelated haplotypes differ, indicating that the genetic diversity of Rp1-related genes is extremely broad in maize. Two unrelated haplotypes with five or nine paralogs had identical resistance phenotypes (Rp1-D) encoded in genes that differed by three nucleotides resulting in a single amino acid substitution. Genes in some haplotypes are more similar to each other than to any of the genes in other haplotypes indicating that they are evolving in a concerted fashion.
| S-EPMC1471013 | biostudies-other
Project description:BackgroundRp1 is a complex locus of maize, which carries a set of genes controlling race-specific resistance to the common rust fungus, Puccinia sorghi. The resistance response includes the "Hypersensitive response" (HR), a rapid response triggered by a pathogen recognition event that includes localized cell death at the point of pathogen penetration and the induction of pathogenesis associated genes. The Rp1-D21gene is an autoactive allelic variant at the Rp1 locus, causing spontaneous activation of the HR response, in the absence of pathogenesis. Previously we have shown that the severity of the phenotype conferred by Rp1-D21 is highly dependent on genetic background.ResultsIn this study we show that the phenotype conferred by Rp1-D21 is highly dependent on temperature, with lower temperatures favoring the expression of the HR lesion phenotype. This temperature effect was observed in all the 14 genetic backgrounds tested. Significant interactions between the temperature effects and genetic background were observed. When plants were grown at temperatures above 30°C, the spontaneous HR phenotype conferred by Rp1-D21 was entirely suppressed. Furthermore, this phenotype could be restored or suppressed by alternately reducing and increasing the temperature appropriately. Light was also required for the expression of this phenotype. By examining the expression of genes associated with the defense response we showed that, at temperatures above 30°C, the Rp1-D21 phenotype was suppressed at both the phenotypic and molecular level.ConclusionsWe have shown that the lesion phenotype conferred by maize autoactive resistance gene Rp1-D21 is temperature sensitive in a reversible manner, that the temperature-sensitivity phenotype interacts with genetic background and that the phenotype is light sensitive. This is the first detailed demonstration of this phenomenon in monocots and also the first demonstration of the interaction of this effect with genetic background. The use of temperature shifts to induce a massive and synchronous HR in plants carrying the Rp1-D21 genes will be valuable in identifying components of the defense response pathway.
| S-EPMC3733612 | biostudies-literature
Project description:The plant hypersensitive response (HR), a rapid cell death at the point of pathogenesis, is mediated by nucleotide-binding site, leucine-rich repeat (NLR) resistance proteins (R-proteins) that recognize the presence of specific pathogen-derived proteins. Rp1-D21 is an autoactive maize NLR R-protein that triggers HR spontaneously. We previously mapped loci associated with variation in the strength of HR induced by Rp1-D21. Here we identify the E3 ligase ZmMIEL1 as the causal gene at a chromosome 10 modifier locus. Transient ZmMIEL1 expression in Nicotiana benthamiana reduced HR induced by Rp1-D21, while suppression of ZmMIEL1 expression in maize carrying Rp1-D21 increased HR. ZmMIEL1 also suppressed HR induced by another autoactive NLR, the Arabidopsis R-protein RPM1D505V, in N. benthamiana. We demonstrated that ZmMIEL1 is a functional E3 ligase and that the effect of ZmMIEL1 was dependent on the proteasome but also that levels of Rp1-D21 and RPM1D505V were not reduced when coexpressed with ZmMIEL1 in the N. benthamiana system. By comparison to a similar system in Arabidopsis, we identify ZmMYB83 as a potential target of ZmMIEL1. Suppression of ZmMYB83 expression in maize lines carrying Rp1-D21 suppressed HR. Suppression of ZmMIEL1 expression caused an increase in ZmMYB83 transcript and protein levels in N. benthamiana and maize. Using coimmunoprecipitation and bimolecular fluorescence complementation assays, we demonstrated that ZmMIEL1 and ZmMYB83 physically interacted. Additionally, ZmMYB83 and ZmMIEL1 regulated the expression of a set of maize very long chain fatty acid (VLCFA) biosynthetic genes that may be involved in regulating HR.
| S-EPMC8126188 | biostudies-literature