• 제목/요약/키워드: Signal Transduction

검색결과 1,010건 처리시간 0.027초

자소엽(紫蘇葉) 에탄올 추출물이 RBL-2H3 비만세포에서 제 1형 알레르기 반응 조절에 미치는 효과 (Effect of Perillae Folium Extract on Regulation of Type 1 Allergic Response in RBL-2H3 Cells)

  • 곡수영;유선애;이승연
    • 대한한방소아과학회지
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    • 제26권1호
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    • pp.36-45
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    • 2012
  • Objectives Perillae Folium (PF) has been widely used in Korean herbal medicines used for treatment of acute and chronic inflammatory diseases, such as rhinitis, asthma, and enteritis. In this study, to investigate the protective effect of PF on type 1 allergic response, we determined whether PF inhibits early or late allergic responses. Methods The effect of PF was analyzed by ELISA,. RT-PCR and Western blot in RBL-2H3 cells. Levels of ${\beta}$-hexosaminidase, interleukin (IL)-4 and TNF-${\alpha}$ were measured using enzyme-linked immunosorbent assays (ELISAs). mRNA levels of cytokines and enzymes were analyzed with RT-PCR. Signal transduction was analyzed with Western blot. Results We found that PF suppressed ${\beta}$-hexosaminidase release in RBL-2H3 by the IgE-DNP-HSA stimulation. PF also significantly inhibited enzymes level, such as COX-1, COX-2, iNOS, and HDC2, along with reduced cytokine levels, such as IL-2, IL-3, IL-4, IL-6, IL-13, and TNF-${\alpha}$ in RBL-2H3. In addition, PF suppressed the phospholyation of ERK1/2, JNK1/2, and $I{\kappa}B{\alpha}$. Conclusions Our results indicate that PF protects against type 1 allergic response and exert an anti-inflammatory effect through the inhibition of degranulation and expression of cytokines and enzymes via the suppression of signal transduction.

Establishment of a Binding Assay System for Screening of the Inhibitors of $p56^{lck}$ SH2 Domain

  • Kim, Jyn-Ho;Hur, Eun-Mi;Yun, Yung-Dae
    • BMB Reports
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    • 제31권4호
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    • pp.370-376
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    • 1998
  • Src-Homology 2 (SH2) domains have a capacity to bind phosphotyrosine-containing sequence context and play essential roles in various cellular signaling pathways. Due to the specific nature of the binding between SH2 domains and their counterpart proteins, inhibitors of SID domain binding have drawn extensive attention as a potential candidate for therapeutic agents. Here, we describe the binding assay system to screen for the ligands or blockers of the SH2 domains with an emphasis on the $p56^{lck}$ SH2 domain. In our assay system, SID domains expressed and purified as fusion proteins to Glutathione-S-transferase (GST) were covalently attached to 96-well microtitre plates through amide bond formation, which were subsequently allowed to bind the biotinylated phosphotyrosine (pY)containing synthetic pep tides. The binding of biotinylated pY peptides was detected by the horseradish peroxidase (HRP)-conjugated streptavidin. Using the various combinations of SH2 domain-pY peptides, we observed that: (1) The binding of pY-peptides to its counterpart SH2 domain is concentration-dependent and saturable; (2) The binding is highly specific for a particular combination of SH2 domain-pY peptide pair; and (3) The binding of Lck SH2-cognate pY-peptides is specifically competed by the nonbiotinylated peptides with expected relative affinity. These results indicate that the established assay system detects the SH2-pY peptide interaction with reproducible sensitivity and specificity and is suitable for screening the specific inhibitors of $p56^{lck}$ SH2 function.

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The Mitogen-Activated Protein Kinase Signal Transduction Pathways in Alternaria Species

  • Xu, Houjuan;Xu, Xiaoxue;Wang, Yu-Jun;Bajpai, Vivek K.;Huang, Lisha;Chen, Yongfang;Baek, Kwang-Hyun
    • The Plant Pathology Journal
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    • 제28권3호
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    • pp.227-238
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    • 2012
  • Mitogen-activated protein kinase (MAPK) cascades are conserved signaling modules in the eukaryotic cells. They are involved in many major cell processes in fungi such as stress responses, vegetative growth, pathogenicity, secondary metabolism and cell wall integrity. In this review, we summarized the advances of research on the MAPK signaling pathways in Alternaria species. As major phytopathogenic fungi, Alternaria species reduce crop production. In contrast to the five MAPK pathways known in yeast, only three MAPK pathways as Fus3/Kss1-type, Hog1-type, and Slt2-type have been characterized in Alternaria. The Fus3/Kss1-type MAPK pathway participates in regulation of vegetative growth, conidiation, production of some cell-wall-degrading enzymes and pathogenicity. The Hog1-type pathway is involved in osmotic and oxidative stress, fungicides susceptibility and pathogenicity. The Slt2-type MAP kinases play an important role on maintaining cell wall integrity, pathogenicity and conidiation. Although recent advances on the MAPK pathways in Alternaria spp. reveal many important features on the pathogenicity, there are many unsolved problems regarding to the unknown MAP kinase cascade components and network among other major signal transduction. Considering the economic loss induced by Alternaria spp., more researches on the MAPK pathways will need to control the Alternaria diseases.

Signal transduction of C-terminal phosphorylation sites for equine follicle stimulating hormone receptor (eFSHR)

  • Seong, Hoon-Ki;Choi, Seung-Hee;Byambaragchaa, Munkhzaya;Min, Kwan-Sik
    • 한국동물생명공학회지
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    • 제35권2호
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    • pp.155-162
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    • 2020
  • Equine follicle stimulating hormone receptor (eFSHR) has a large extracellular domain and an intracellular domain containing approximately 10 phosphorylation sites within the G protein-coupled receptor. This study was conducted to analyze the function of phosphorylation sties at the eFSHR C-terminal region. We constructed a mutant of eFSHR, in which the C-terminal cytoplasmic tail was truncated at residue 641 (eFSHR-t641). This removed 10 potential phosphorylation sites from the C-terminal region of the intracellular loop. The eFSHR-wild type (eFSHR-wt) and eFSHR-t641 cDNAs were subcloned into the pCMV-ARMS1-PK2 expression vector. These plasmids were transfected into PathHunter CHO-K1 Parental cells expressing β-arrestin 2 enzyme acceptor fusion protein and analyzed for agonist-induced cAMP response. The cAMP response in cells expressing eFSHR-t641 was lower than the response in cells expressing eFSHR-wt. EC50 values of eFSHR-wt and eFSHR-t641 were 1079 ng/mL and 1834 ng/mL, respectively. eFSHR-t641 was approximately 0.58-fold compared with that of eFSHR-wt. The maximal response in eFSHR-wt and eFSHR-t641 was 24.7 nM and 16.7 nM, respectively. The Rmax value of phosphorylation sites in eFSHR-t641 was also decreased to approximately 68.4% of that in eFSHR-wt. The collective data implicate that the phosphorylation sites in the eFSHR C-terminal region have a pivotal role in signal transduction in PathHunter CHO-K1 cells, and indicate that β-arrestin is involved in coupling the activated receptors to the internalization system.