• BMB Reports
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• 제49권12호
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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.

• BMB Reports
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• 제40권4호
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• pp.562-570
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• 2007

Soluble or cell-bound IL-1 receptor accessory protein (IL-1RAcP) does not bind IL-1 but rather forms a complex with IL-1 and IL-1 receptor type I (IL-1RI) resulting in signal transduction. Synthetic peptides to various regions in the Ig-like domains of IL-1RAcP were used to produce antibodies and these antibodies were affinity-purified using the respective antigens. An anti-peptide-4 antibody which targets domain III inhibited 70% of IL-$1\beta$-induced productions of IL-6 and PGE2 from 3T3-L1 cells. Anti-peptide-2 or 3 also inhibited IL-1-induced IL-6 production by 30%. However, antipeptide-1 which is directed against domain I had no effect. The antibody was more effective against IL-$1\beta$ compared to IL-$1\alpha$. IL-1-induced IL-6 production was augmented by coincubation with PGE2. The COX inhibitor ibuprofen blocked IL-1-induced IL-6 and PGE2 production. These results confirm that IL-1RAcP is essential for IL-1 signaling and that increased production of IL-6 by IL-1 needs the co-induction of PGE2. However, the effect of PGE2 is independent of expressions of IL-1RI and IL-1RAcP. Our data suggest that domain III of IL-1RAcP may be involved in the formation or stabilization of the IL-1RI/IL-1 complex by binding to epitopes on domain III of the IL-1RI created following IL-1 binding to the IL-1RI.

• Natural Product Sciences
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• 제3권1호
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• pp.29-37
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• 1997

Protein Kinase C (PKC) is generally believed to play a central role in signal transduction, cellular growth control, gene expression, and tumor promotion. And it has been suggested that inhibitors of PKC might play important roles for the prevention and treatment of cancer. In order to investigate the possible inhibitors of PKC from natural products, PKC receptor binding assay was performed using bovine brain particulate as a source of PKC and the amount of $[^3H]Phorbol$ 12,13-dibutyrate (PDBu) bound to PKC was measured in the presence of test materials. Total methanol extracts from 100 kinds of natural products were partitioned into 3 fractions (n-hexane, ethyl acetate and aqueous layer) and their binding ability to the regulatory domain of PKC was evaluated. The ethyl acetate fractions of Morus alba $(roots,\;IC_{50}:\;156.6\;{\mu}g/ml)$, Rehmannia glutinosa $(roots,\;IC_{50}:\;134.3\;{\mu}g/ml)$, Lysimachia foenum-graecum $(roots,\;IC_{50}:\;167.8\;{\mu}g/ml)$, Polygonum cuspidata $(roots,\;IC_{50}:\;157.3\;{\mu}g/ml)$, Cnidium officinale $(aerial\;parts,\;IC_{50}:\;145.2\;{\mu}g/ml)$, and the hexane $(IC_{50}:\;179.3\;{\mu}g/ml)$ and the EtOAc fraction of Symplocarpus nipponicus $(roots,\;IC_{50}:\;155.9\;{\mu}g/ml)$ showed inhibitory activity of $[^3H]PDBu$ binding to PKC.

• 한국발생생물학회지:발생과생식
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• 제13권4호
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• pp.249-256
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• 2009

구조적으로 estrogen 수용체(estrogen receptor, ER)와 유사한 estrogen receptor-related receptor(ERR)는 포유동물에서 배발생 후기에 외배엽 형성과 관련되어 있다고 알려진 고아핵수용체(orphan nuclear receptor)이다. ERR은 ER과 DNA binding domain의 보존성은 유사하지만, ligand 결합 및 전사 활성은 다르다. 포유동물의 ERR에 관한 연구에 비하여 해양 무척추동물의 ERR에 대한 기능 연구는 매우 부족하다. 본 연구에서는 우리나라 동해안에 주로 서식하는 둥근성게(Strongylocentrotus nudus) ERR의 초기 발생기 유전자 발현 변화와 전사 활성 기능을 조사하기 위해 먼저 polymerase chain reaction(PCR)을 이용하여 cDNA를 동정하였다. 둥근성게 ERR은 S. purpuratus와 91%의 높은 상동성을 보였으며, 계통수 분석을 통해 무척추동물 ERR의 clade에 포함되는 것을 알았다. 둥근성게 배발생 시기에 ERR 유전자 발현을 알아보기 위하여 real-time PCR을 실시한 결과, 4~64세포기와 유생기에 mRNA level이 높은 경향을 나타내었다. 또한 호르몬 및 co-regulator에 의한 둥근성게 ERR의 전사 활성을 조사한 결과, 호르몬에 의한 특이성은 확인되지 않았지만, peroxisome proliferator activated receptor-(PPAR) $\gamma$ coactivator $1\alpha$(PGC-$1\alpha$)가 둥근성게 ERR의 coactivator임을 입증할 수 있었다. 이 연구 결과는 향후 새로운 ligand 발굴과 coregulator와 의 상호작용 연구에 도움이 될 것으로 사료된다.

• IMMUNE NETWORK
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• 제20권5호
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• pp.41.1-41.11
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• 2020

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) is a positive-sense single-stranded RNA (+ssRNA) that causes coronavirus disease 2019 (COVID-19). The viral genome encodes twelve genes for viral replication and infection. The third open reading frame is the spike (S) gene that encodes for the spike glycoprotein interacting with specific cell surface receptor - angiotensin converting enzyme 2 (ACE2) - on the host cell membrane. Most recent studies identified a single point mutation in S gene. A single point mutation in S gene leading to an amino acid substitution at codon 614 from an aspartic acid 614 into glycine (D614G) resulted in greater infectivity compared to the wild type SARS-CoV2. We were interested in investigating the mutation region of S gene of SARS-CoV2 from Korean COVID-19 patients. New mutation sites were found in the critical receptor binding domain (RBD) of S gene, which is adjacent to the aforementioned D614G mutation residue. This specific sequence data demonstrated the active progression of SARS-CoV2 by mutations in the RBD of S gene. The sequence information of new mutations is critical to the development of recombinant SARS-CoV2 spike antigens, which may be required to improve and advance the strategy against a wide range of possible SARS-CoV2 mutations.

• Journal of Microbiology and Biotechnology
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• 제25권8호
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• pp.1227-1233
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• 2015

Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis through binding to its specific receptors, which mainly occurs to VEGF receptor 2 (VEGFR-2), a kinase insert domain-containing receptor. Therefore, the disruption of VEGFR-2 signaling provides a promising therapeutic approach for the treatment of cancer by inhibiting abnormal or tumorinduced angiogenesis. To explore this potential, we expressed the catalytic domain of VEGFR-2 (VEGFR-2-CD) as a soluble active kinase in Escherichia coli. The recombinant protein was purified and the VEGFR-2-CD activity was investigated. The obtained VEGFR-2-CD showed autophosphorylation activity and phosphate transfer activity comparable to the commercial enzyme. Furthermore, the IC₅₀ value of known VEGFR-2 inhibitor was determined using the purified VEGFR-2-CD. These results indicated a possibility for functional and economical VEGFR-2-CD expression in E. coli to use for inhibitor screening.

• BMB Reports
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• 제31권5호
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• pp.419-426
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• 1998

The nuclear hormone receptor superfamily currently includes approximately equal numbers of conventional receptors and orphan receptors, which do not have known ligands. Here, we review recent progress from this laboratory on three orphans, two of which are moving from orphan to conventional receptor status. Perhaps the most unusual is CAR, which is a constitutive transactivator in the absence of ligands but becomes transcriptionally inactive in the presence of its ligands, which are androgen metabolites. The response of CAR to its ligands is thus opposite to that of the conventional receptor paradigm. RIP14 (also known as FXR) is activated by both all-trans retinoic acid and a synthetic retinoid previously thought to specifically target the retinoic acid receptors (RARs), and thus appears to be a novel retinoid receptor. Finally, SHP is a novel orphan that lacks a DNA binding domain and interacts with a number of other receptor superfamily members. While it generally inhibits its targets, including CAR, the retinoid X receptor (RXR), and the estrogen receptor (ER), it stimulates transactivation by the orphan SF-1.

• Molecules and Cells
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• 제39권2호
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• pp.156-162
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• 2016

Estrogen receptor ${\alpha}$ (ER-${\alpha}$), which is involved in bone metabolism and breast cancer, has been shown to have transcriptional targets. Dlx3 is essential for the skeletal development and plays an important role in osteoblast differentiation. Various osteogenic stimulators and transcription factors can induce the protein expression of Dlx3. However, the regulatory function of ER-${\alpha}$ in the Dlx3 mediated osteogenic process remains unknown. Therefore, we investigated the regulation of Dlx3 and found that ER-${\alpha}$ is a positive regulator of Dlx3 transcription in BMP2-induced osteoblast differentiation. We also found that ER-${\alpha}$ interacts with Dlx3 and increases its transcriptional activity and DNA binding affinity. Furthermore, we demonstrated that the regulation of Dlx3 activity by ER-${\alpha}$ is independent of the ligand (estradiol) binding domain. These results indicate that Dlx3 is a novel target of ER-${\alpha}$, and that ER-${\alpha}$ regulates the osteoblast differentiation through modulation of Dlx3 expression and/or interaction with Dlx3.

• BMB Reports
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• 제32권3호
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• pp.279-287
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• 1999

The aromatic hydrocarbon receptor (AhR) is a cytosolic protein that binds the environmental pollutant, dioxin. The liganded AhR translocates into the nucleus where it heterimerizes with a constitutive nuclear protein, AhR nuclear translocator (Arnt). The N-terminal regions of both AhR and Arnt contain basic helix-loop-helix (bHLH) and Per-AhR-Arnt-Sim (PAS) motifs that are required for DNA binding, dimerization, and ligand binding whereas the C-terminal regions of both AhR and Arnt contain transactivation domains. Here, results from the mammalian two-hybrid system indicate that Arnt can make a homodimer but AhR cannot. In the presence of dioxin, the interaction between AhR and Arnt is stronger than that of the Arnt homodimer, suggesting that Arnt prefers to make a heterodimer with the liganded AhR rather than a homodimer. Transfection analyses using the GAL4-driven reporter system suggest that AhR's N-terminal region represses its own transactivation domain, as well as exogenous transactivation domains such as Sp 1 and VP16. Interestingly, the repressed transactivation domains of AhR are activated by ligand-dependent heterodimerization with Arnt. These observations suggest that heterodimerzation with Arnt is necessary not only for DNA binding but also for activation of the repressed transactivation capability of AhR.

• Journal of Veterinary Science
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• 제22권1호
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• pp.12.1-12.11
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• 2021

Background: Bats have been considered natural reservoirs for several pathogenic human coronaviruses (CoVs) in the last two decades. Recently, a bat CoV was detected in the Republic of Korea; its entire genome was sequenced and reported to be genetically similar to that of the severe acute respiratory syndrome CoV (SARS-CoV). Objectives: The objective of this study was to compare the genetic sequences of SARS-CoV, SARS-CoV-2, and the two Korean bat CoV strains 16BO133 and B15-21, to estimate the likelihood of an interaction between the Korean bat CoVs and the human angiotensin-converting enzyme 2 (ACE2) receptor. Methods: The phylogenetic analysis was conducted with the maximum-likelihood (ML) method using MEGA 7 software. The Korean bat CoVs receptor binding domain (RBD) of the spike protein was analyzed by comparative homology modeling using the SWISS-MODEL server. The binding energies of the complexes were calculated using PRODIGY and MM/GBGA. Results: Phylogenetic analyses of the entire RNA-dependent RNA polymerase, spike regions, and the complete genome revealed that the Korean CoVs, along with SARS-CoV and SARS-CoV-2, belong to the subgenus Sarbecovirus, within BetaCoVs. However, the two Korean CoVs were distinct from SARS-CoV-2. Specifically, the spike gene of the Korean CoVs, which is involved in host infection, differed from that of SARS-CoV-2, showing only 66.8%-67.0% nucleotide homology and presented deletions within the RBD, particularly within regions critical for cross-species transmission and that mediate interaction with ACE2. Binding free energy calculation revealed that the binding affinity of Korean bat CoV RBD to hACE2 was drastically lower than that of SARS-CoV and SARS-CoV-2. Conclusions: These results suggest that Korean bat CoVs are unlikely to bind to the human ACE2 receptor.