• Title/Summary/Keyword: molecular functions

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Anti-inflammatory Effects of 8α-hydroxy pinoresinol isolated from Nardostachys jatamansi on Lipopolysaccharide-induced Inflammatory Response in RAW 264.7 Cells. (LPS로 유도된 RAW 264.7 세포의 염증반응에서 감송향(甘松香)에서 추출한 8α-hydroxy pinoresinol의 항염증 효과)

  • Choi, Sun Bok;Park, Sung-Joo
    • The Korea Journal of Herbology
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    • v.31 no.5
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    • pp.1-6
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    • 2016
  • Objectives : Nardostachys jatamansi (NJ) is a medicinal herb that has been reported in various traditional systems of medicine for its use in antispasmodic, a digestive stimulant, skin diseases. Previous studies have already reported that NJ effectively protects against inflammation. However, the active compound in NJ is unknown. Therefore, in the present study, we analyzed effects of a compound, 8α-hydroxy pinoresinol (HP), isolated from NJ against lipopolysaccharide (LPS) induced inflammation in RAW 264.7 cells.Methods : To examine the anti-inflammatory effect of HP against LPS, intraperitoneally pre-treat the HP (100, 200, 500 and 1,000 nM) 1 h prior to LPS challenges. LPS was stimulated with 500 ng/ml in RAW 264.7 cells. To identify the anti-inflammatory effect of HP, we measured inflammatory mediators such as inducible nitric oxide synthase (iNOS) and its derivative nitric oxide (NO), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2). Also we evaluated molecular mechanisms including mitogen-activated protein kinases (MAPKs) and nuclear factor-kappaB (NF-κB) activation by western blot.Results : The HP inhibited production of inflammatory mediators, such as iNOS and its derivative NO, COX-2 and PGE2 in LPS- induced inflammationin RAW 264.7 cells. Additionally, HP also inhibited activation of p38 pathway signaling but not extracellularsignal-regulatedkinase (ERK), c-jun NH2-terminal kinase (JNK), and NF-κB.Conclusion : Our results suggest that HP has anti-inflammatory functions through the dephosphorylation of p38 and HP can provide beneficial strategy for prevention and therapy of inflammation.

Comparison of DNase activities from excretory/secretory productsof Haemonchus contortus fenbendazole-resistantand -susceptible isolates (Fenbendazole에 저항성과 감수성을 지닌 염전위충의 분비배설물에서의 DNase 활성 비료)

  • Kwak, Dongmi
    • Korean Journal of Veterinary Research
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    • v.44 no.3
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    • pp.455-462
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    • 2004
  • Change in ${\beta}$-tubulin nucleic acid and protein sequences was the only known difference between Haemonchus contortus fenbendazole (FBZ)-resistant and -susceptible isolates. This change was sufficient to determine the pathologic effect induced by FBZ treatment. This research was initiated to investigate further differences from these two isolates. Since ${\beta}$-tubulin is involved in formation of microtubule, which has functions in secretory vesicle transport, DNase activities from excretory/secretory products (ESP) of the two isolates were compared, based on pH, sensitivity to DNase inhibitors, molecular masses and production of 3'-OH. The most significant difference detected was that a 38.5 kDa DNase activity was identified from ESP of H. contortus FBZ-susceptible isolates but not from those of H. contortus FBZ-resistant isolates. However, it was shown that the 38.5 kDa DNase is expressed with similar level of activity in intestine and whole worm of H. contortus FBZ-resistant and -susceptible isolates. This result demonstrated that the secretory transport pathway of the 38.5 kDa DNase was inhibited by unknown mechanisms, which may be related with ${\beta}$-tubulin sequence change in FBZ-resistant isolates. Other DNases of 34, 36 and 37 kDa were detected from ESP of both H. contortus FBZ-resistant and -susceptible isolates. Overall DNase activities found from ESP of these two isolates were not inhibited by 10 mM EDTA at pH 5.0, but largely inhibited by pH 7.0. In addition, DNase activities in two isolates produced DNA fragments with mixtures of 3'- hydroxyls (OH) and 3'-phosphates (P) at each pH although the 3'-end labeling ratios at pH 5.0 and 7.0 were shown different. Identification of inhibition of the 38.5 kDa DNase secretion in FBZ-resistant isolates suggests existence of further differences, in addition to ${\beta}$-tubulin sequence change, in two isolates. This shows complex effect of FBZ on H. contortus biological mechanisms.

Thermal Denaturation of the Apo-cyclic AMP Receptor Protein and Noncovalent Interactions between Its Domains

  • Won, Hyung-Sik;Seo, Min-Duk;Ko, Hyun-Suk;Choi, Wahn Soo;Lee, Bong-Jin
    • Molecules and Cells
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    • v.26 no.1
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    • pp.61-66
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    • 2008
  • Cyclic AMP receptor protein (CRP) is allosterically activated by cAMP and functions as a global transcription regulator in enteric bacteria. Structural information on CRP in the absence of cAMP (apo-CRP) is essential to fully understand its allosteric behavior. In this study we demonstrated interdomain interactions in apo-CRP, using a comparative thermodynamic approach to the intact protein and its isolated domains, which were prepared either by limited proteolysis or using recombinant DNA. Thermal denaturation of the intact apo-CRP, monitored by differential scanning calorimetry, revealed an apparently single cooperative transition with a slight asymmetry. Combined with circular dichroism and fluorescence analysis, the thermal denaturation of apo-CRP could be interpreted as a coupled process involving two individual transitions, each attributable to a structural domain. When isolated individually, both of the domains exhibited significantly altered thermal behavior, thus pointing to the existence of non-covalent interdomain interactions in the intact apo-CRP. These observations suggest that the allosteric conformational change of CRP upon binding to cAMP is achieved by perturbing or modifying pre-existing interdomain interactions. They also underline the effectiveness of a comparative approach using calorimetric and structural probes for studying the thermodynamics of a protein.

Regulation of BAD Protein by PKA, PKCδ and Phosphatases in Adult Rat Cardiac Myocytes Subjected to Oxidative Stress

  • Cieslak, Danuta;Lazou, Antigone
    • Molecules and Cells
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    • v.24 no.2
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    • pp.224-231
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    • 2007
  • $H_2O_2$, as an example of oxidative stress, induces cardiac myocyte apoptosis. Bcl-2 family proteins are key regulators of the apoptotic response while their functions can be regulated by post-translational modifications including phosphorylation, dimerization or proteolytic cleavage. In this study, we examined the role of various protein kinases in regulating total BAD protein levels in adult rat cardiac myocytes undergoing apoptosis. Stimulation with 0.1 mM $H_2O_2$, which induces apoptosis, resulted in a marked down-regulation of BAD protein, which is attributed to cleavage by caspases since it can be restored in the presence of a general caspase inhibitor. Inhibition of PKC, p38-MAPK, ERK1/2 and PI-3-K did not influence the reduced BAD protein levels observed after stimulation with $H_2O_2$. On the contrary, inhibition of PKA or specifically $PKC{\delta}$ resulted in up-regulation of BAD. Decreased caspase 3 activity was observed in $H_2O_2$ treated cells after inhibition of PKA or $PKC{\delta}$ whereas inhibition of PKA also resulted in improved cell survival. Furthermore, addition of okadaic acid to inhibit selected phosphatases resulted in enhanced BAD cleavage. These data suggest that, during oxidative stress-induced cardiac myocyte apoptosis, there is a caspase-dependent down-regulation of BAD protein, which seems to be regulated by coordinated action of PKA, $PKC{\delta}$ and phosphatases.

The Efficiency of RNA Interference in Bursaphelenchus xylophilus

  • Park, Jung-Eun;Lee, Kyong Yun;Lee, Se-Jin;Oh, Wan-Suk;Jeong, Pan-Young;Woo, Taeha;Kim, Chang-Bae;Paik, Young-Ki;Koo, Hyeon-Sook
    • Molecules and Cells
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    • v.26 no.1
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    • pp.81-86
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    • 2008
  • RNA interference (RNAi) was performed on several essential genes in the pinewood nematode Bursaphelenchus xylophilus, which causes pine wilt disease. Double-stranded RNA (dsRNA) was delivered to larvae or adult worms by soaking, electroporation, or microinjection. Soaking and electroporation of L2-L3 stage worms in solutions containing dsRNA for essential genes induced over 25% lethality after 5 days, and gene-specific phenotypes were observed. This lethality agreed with significant reductions of the targeted transcripts, as assayed by reverse-transcription coupled with real time PCR. Microinjection was the most efficient route as measured by the hatching rate of F1 embryos, which was reduced by 46%. When adult worms were soaked in dsRNA, lethality was induced in the F1 larvae, revealing the persistence of knockdown phenotypes. The penetrance of the RNAi phenotypes for essential genes was relatively low but consistent, indicating that RNAi should be useful for studying the in vivo functions of B. xylophilus gene products.

CaPUB1, a Hot Pepper U-box E3 Ubiquitin Ligase, Confers Enhanced Cold Stress Tolerance and Decreased Drought Stress Tolerance in Transgenic Rice (Oryza sativa L.)

  • Min, Hye Jo;Jung, Ye Jin;Kang, Bin Goo;Kim, Woo Taek
    • Molecules and Cells
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    • v.39 no.3
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    • pp.250-257
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    • 2016
  • Abiotic stresses such as drought and low temperature critically restrict plant growth, reproduction, and productivity. Higher plants have developed various defense strategies against these unfavorable conditions. CaPUB1 (Capsicum annuum Putative U-box protein 1) is a hot pepper U-box E3 Ub ligase. Transgenic Arabidopsis plants that constitutively expressed CaPUB1 exhibited drought-sensitive phenotypes, suggesting that it functions as a negative regulator of the drought stress response. In this study, CaPUB1 was over-expressed in rice (Oryza sativa L.), and the phenotypic properties of transgenic rice plants were examined in terms of their drought and cold stress tolerance. Ubi:CaPUB1 T3 transgenic rice plants displayed phenotypes hypersensitive to dehydration, suggesting that its role in the negative regulation of drought stress response is conserved in dicot Arabidopsis and monocot rice plants. In contrast, Ubi:CaPUB1 progeny exhibited phenotypes markedly tolerant to prolonged low temperature ($4^{\circ}C$) treatment, compared to those of wild-type plants, as determined by survival rates, electrolyte leakage, and total chlorophyll content. Cold stress-induced marker genes, including DREB1A, DREB1B, DREB1C, and Cytochrome P450, were more up-regulated by cold treatment in Ubi:CaPUB1 plants than in wild-type plants. These results suggest that CaPUB1 serves as both a negative regulator of the drought stress response and a positive regulator of the cold stress response in transgenic rice plants. This raises the possibility that CaPUB1 participates in the cross-talk between drought and low-temperature signaling pathways.

Inhibitory Mechanism of Blood Coagulation by the Anticoagulant Polysaccharide from Coriolus versicolor (구름버섯 기원 항응고성 다당류의 혈액응고 저해기작)

  • Lee, Hyun-Sun;Kweon, Mee-Hyang;Lim, Wang-Jin;Sung, Ha-Chin;Yang, Han-Chul
    • Korean Journal of Food Science and Technology
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    • v.29 no.4
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    • pp.817-822
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    • 1997
  • Inhibitory mechanism of the anticoagulant polysaccharide purified from the fruit body of Coriolus versicolor was investigated in this paper. The anticoagulant polysaccharide (CV-40-Va-1) was proposed to have functions of the inhibition of intrinsic pathway in the blood coagulation pathway together with the interuption of a human platelet aggregation induced by von Willebrand factor (vWF). CV-40-Va-I inhibited other factors of the coagulation cascade such as factor VIII, IX, and as well as thrombin. Especially, CV-40-Va-I inhibited the fibrin formation mediated by thromin, however the polysaccharide did not affect the fibrin formation directly but affected the anticoagulant activity through the activation of antithrombin III. The sulfation of the anticoagulant polysaccharide increased the anticoagulant activity, showing that the sulfate concentration of anticoagulant polysaccharide was important factor in the blood coagulation cascade. Low molecular weight subfraction (MW 1,000) obtained by partial hydrolysis of the CV-40-Va-1 generated potent antiplatelet activity, but showed decreased anticoagulant activity.

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Molecular Profiling of Rhizosphere Bacterial Communities Associated with Prosopis juliflora and Parthenium hysterophorus

  • Jothibasu, K.;Chinnadurai, C.;Sundaram, S.P.;Kumar, K.;Balachandar, D.
    • Journal of Microbiology and Biotechnology
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    • v.22 no.3
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    • pp.301-310
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    • 2012
  • Prosopis juliflora and Parthenium hysterophorus are the two arid, exotic weeds of India that are characterized by distinct, profuse growth even in nutritionally poor soils and environmentally stressed conditions. Owing to the exceptional growth nature of these two plants, they are believed to harbor some novel bacterial communities with wide adaptability in their rhizosphere. Hence, in the present study, the bacterial communities associated with the rhizosphere of Prosopis and Parthenium were characterized by clonal 16S rRNA gene sequence analysis. The culturable microbial counts in the rhizosphere of these two plants were higher than bulk soils, possibly influenced by the root exudates of these two plants. The phylogenetic analysis of V1_V2 domains of the 16S rRNA gene indicated a wider range of bacterial communities present in the rhizosphere of these two plants than in bulk soils and the predominant genera included Acidobacteria, Gammaproteobacteria, and Bacteriodetes in the rhizosphere of Prosopis, and Acidobacteria, Betaproteobacteria, and Nitrospirae in the Parthenium rhizosphere. The diversity of bacterial communities was more pronounced in the Parthenium rhizosphere than in the Prosopis rhizosphere. This culture-independent bacterial analysis offered extensive possibilities of unraveling novel microbes in the rhizospheres of Prosopis and Parthenium with genes for diverse functions, which could be exploited for nutrient transformation and stress tolerance in cultivated crops.

Listener Auditory Perception Enhancement using Virtual Sound Source Design for 3D Auditory System

  • Kang, Cheol Yong;Mariappan, Vinayagam;Cho, Juphil;Lee, Seon Hee
    • International journal of advanced smart convergence
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    • v.5 no.4
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    • pp.15-20
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    • 2016
  • When a virtual sound source for 3D auditory system is reproduced by a linear loudspeaker array, listeners can perceive not only the direction of the source, but also its distance. Control over perceived distance has often been implemented via the adjustment of various acoustic parameters, such as loudness, spectrum change, and the direct-to-reverberant energy ratio; however, there is a neglected yet powerful cue to the distance of a nearby virtual sound source that can be manipulated for sources that are positioned away from the listener's median plane. This paper address the problem of generating binaural signals for moving sources in closed or in open environments. The proposed perceptual enhancement algorithm composed of three main parts is developed: propagation, reverberation and the effect of the head, torso and pinna. For propagation the effect of attenuation due to distance and molecular air-absorption is considered. Related to the interaction of sounds with the environment, especially in closed environments is reverberation. The effects of the head, torso and pinna on signals that arrive at the listener are also objectives of the consideration. The set of HRTF that have been used to simulate the virtual sound source environment for 3D auditory system. Special attention has been given to the modelling and interpolation of HRTFs for the generation of new transfer functions and definition of trajectories, definition of closed environment, etc. also be considered for their inclusion in the program to achieve realistic binaural renderings. The evaluation is implemented in MATLAB.

Human Liver Specific Transcriptional Factor TCP10L Binds to MAD4

  • Jiang, Dao-Jun;Yu, Hong-Xiu;Hexige, Sa-Yin;Guo, Ze-Kun;Wang, Xiang;Ma, Li-Jie;Chen, Zheng;Zhao, Shou-Yuan;Yu, Long
    • BMB Reports
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    • v.37 no.4
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    • pp.402-407
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    • 2004
  • A human gene T-complex protein 10 like (TCP10L) was cloned in our lab. A previous study showed that it expressed specifically in the liver and testis. A transcription experiment revealed that TCP10L was a transcription factor with transcription inhibition activity. In this study, the human MAD4 was identified to interact with TCP10L by a yeast two-hybrid screen. This finding was confirmed by immunoprecipitation and subcellular localization experiments. As MAD4 is a member of the MAD family, which antagonizes the functions of MYC and promotes cell differentiation, the biological function of the interaction between TCP10L and MAD4 may be to maintain the differentiation state in liver cells. Also, we propose that the up-regulation of Myc is caused by the down-regulation of TCP10L in human hepatocarcinomas.