• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.3091-3094
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• 2012

• BMB Reports
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• v.49 no.12
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• pp.693-698
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• 2016

In this study, a tissue-specific GAL4/UAS activation tagging system was used for the characterization of genes which could induce lethality when ubiquitously expressed. A dominant mutant exhibiting stunted growth was isolated and named defective root development 1-D (drd1-D). The T-DNA tag was located within the promoter region of AtTX12, which is predicted to encode a truncated nucleotide-binding leucine-rich repeat (NLR) protein, containing a Toll/interleukin-1 receptor (TIR) domain. The transcript levels of AtTX12 and defense-related genes were elevated in drd1-D, and the misexpression of AtTX12 recapitulated the drd1-D phenotypes. In the presence of ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1), a key transducer of signals triggered by TIR-type NLRs, a low-level of AtTX12 misexpression induced strong defective phenotypes including seedling lethality whereas, in the absence of EDS1, a high-level of AtTX12 misexpression induced weak growth defects like dwarfism, suggesting that AtTX12 might function mainly in an EDS1-dependent and partially in an EDS1-independent manner.

• Journal of Life Science
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• v.21 no.1
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• pp.36-43
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• 2011

Diabetes mellitus is associated with vascular complications. Diabetic patients exhibit high levels of glycated adducts in serum compared to non-diabetic individuals. The aim of this study was to investigate whether extracellular glycated albumin (GA) predisposes vascular smooth muscle cells (VSMCs) to pro-inflammatory phenotype. Exposure of rat aortic smooth muscle cells (AoSMCs) to GA not only enhanced interleukin-6 (IL-6) release but also activated promoter activity of the IL-6 gene. GA-induced IL-6 promoter activation was suppressed by dominant-negative forms of Toll-like receptor (TLR)-4 and myeloid differentiation factor 88 (MyD88), but not by dominant-negative-forms of TLR-2 and TIR-domain-containing adapter-inducing interferon-$\beta$ (TRIF). Extracellular signal-regulated kinase (ERK) inhibition and diphenyleneiodium (DPI) also attenuated IL-6 induction by GA. Mutation at the nuclear factor-${\kappa}B$ (NF-${\kappa}B$)-binding site in the IL-6 promoter region suppressed promoter activation in response to GA. The present study proposes that GA would contribute to inflammatory reaction in the stressed vasculature by inducing IL-6 in VSMCs, and that TLR-4, EKR, and NF-${\kappa}B$ play active roles in the process.

• Journal of Life Science
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• v.34 no.9
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• pp.666-672
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• 2024

Plants recognize pathogens through intracellular receptors that trigger defense signaling. Nucleotide-binding leucine-rich repeat (NLR) proteins within a cell specifically recognize pathogenic molecules (effectors), leading to signal transduction that ultimately triggers the cell death pathway, thereby inducing effector-triggered immunity in plants. NLR proteins are broadly categorized into two types based on their N-terminal domains: coiled-coil domain NLRs (CNLs) and toll/interleukin-1 receptor (TIR) domain NLRs (TNLs) are defined by their unique N-terminal domains. The TIR domain, which is responsible for activates nicotinamide adenine dinucleoside hydrolases (NADases), is crucial for the degradation of the NAD+ cofactor. TNL-dependent immune signaling involves lipase-like proteins known as Enhanced Disease Susceptibility 1 (EDS1) and its partners Phytoalexin Deficient 4 (PAD4) and Senescence-Associated Gene 101 (SAG101). This immune system also requires helper NLR subfamilies, such as activated disease resistance 1 (ADR1) and N requirement gene 1 (NRG1). The catalytic activity of TIR domain proteins generates various small molecules reported to activate plant's immune responses. These small molecules bind to specific sites on EDS1-PAD4 and EDS1-SAG101, inducing structural changes in the EP domain, and subsequently enabling interaction with ADR1 or NRG1. Here, we will discuss the characteristics of these small molecules and describe their relationships with protein complexes based on their structural and biochemical characteristics. We will also discuss how these small molecules can activate immune pathways.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.130-137
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• 2007

A disease resistance related gene, MbR7, was identified in the wild apple species, Malus baccata. The MbR7 gene has a single open reading frame (ORF) of 3,288 nucleotides potentially encoding a 1,095-amino acid protein. Its deduced amino acid sequence resembles the N protein of tobacco and the NL27 gene of potato and has several motifs characteristic of a TIR-NBS-LRR R gene subclass. Ectopic expression of MbR7 in Arabidopsis enhanced the resistance against a virulent pathogen, Pseudomonas syringae pv. tomato DC3000. Microarray analysis confirmed the induction of defense-related gene expression in 35S::MbR7 heterologous Arabidopsis plants, indicating that the MbR7 gene likely activates a downstream resistance pathway without interaction with pathogens. Our results suggest that MbR7 can be a potential target gene in developing a new disease-resistant apple variety.

• Journal of Life Science
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• v.18 no.12
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• pp.1637-1643
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• 2008

This study has investigated whether extracellular HSP90 predisposes vascular smooth muscle cells (VSMCs) to pro-inflammatory phenotype. Exposure of rat aortic smooth muscle cells to HSP90 not only enhanced IL-6 release but also profoundly induced IL-6 transcript via promoter activation. HSP90-induced IL-6 promoter activation was suppressed by dominant-negative forms of Toll-like receptor (TLR)-4 and myeloid differentiation factor 88 (MyD88), but not by dominant-negative-forms of TLR-3 and TIR-domain-containing adapter-inducing interferon-${\beta}$ (TRIF). Curcumin, which inhibits dimerization of TLR-4, also attenuated the IL-6 induction by HSP90. Mutation at the NF-${\kappa}B$- or C/EBP-binding site in the IL-6 promoter region suppressed the promoter activation in response to HSP90. The gene delivery of $I{\kappa}B$ using recombinant adenoviruses and treatment with resveratrol, which inhibit NF-${\kappa}B$ activity, attenuated the HSP90-induced IL-6 release from VSMCs. The present study proposes that extracellular HSP90 would contribute to inflammatory reaction in the stressed vasculature by inducing IL-6 in VSMCs, and that TLR-4 and NF-${\kappa}B$ would play active roles in the process.