• Title/Summary/Keyword: positive regulator

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OsAREB1, an ABRE-binding protein responding to ABA and glucose, has multiple functions in Arabidopsis

  • Jin, Xiao-Fen;Xiong, Ai-Sheng;Peng, Ri-He;Liu, Jin-Ge;Gao, Feng;Chen, Jian-Min;Yao, Quan-Hong
    • BMB Reports
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    • v.43 no.1
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    • pp.34-39
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    • 2010
  • Expression patterns of OsAREB1 revealed that expression of OsAREB1 gene can be induced by ABA, PEG and heat. Yeast one-hybrid assay demonstrated it can bind to ABA-responsive element (ABRE), which was found in most stress-induced genes. Transgenic Arabidopsis over-expressing OsAREB1 had different responses to ABA and glucose compared to wild-type plants, which suggest OsAREB1 might have a crucial role in these two signaling pathways. Further analysis indicate that OsAREB1 have multiple functions in Arabidopsis. First, OsAREB1 transgenic plants had higher resistance to drought and heat, and OsAREB1 up-regulated the ABA/stress related gene such as RD29A and RD29B. Second, it delayed plant flowering time by down-regulating the expression of flowering-related genes, such as FT, SOC1, LFY and AP1. Due to the dates, OsAREB1 may function as a positive regulator in drought/heat stresses response, but a negative regulator in flowering time in Arabidopsis.

An ARIA-Interacting AP2 Domain Protein Is a Novel Component of ABA Signaling

  • Lee, Sun-ji;Cho, Dong-im;Kang, Jung-youn;Kim, Soo Young
    • Molecules and Cells
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    • v.27 no.4
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    • pp.409-416
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    • 2009
  • ADAP is an AP2-domain protein that interacts with ARIA, which, in turn, interacts with ABF2, a bZIP class transcription factor. ABF2 regulates various aspects of the abscisic acid (ABA) response by controlling the expression of a subset of ABA-responsive genes. Our expression analyses indicate that ADAP is expressed in roots, emerging young leaves, and flowers. We found that adap knockout mutant lines germinate more efficiently than wild-type plants and that the mutant seedlings grow faster. This suggests that ADAP is involved in the regulation of germination and seedling growth. Both germination and post-germination growth of the knockout mutants were partially insensitive to ABA, which indicates that ADAP is required for a full ABA response. The survival rates for mutants from which water was withheld were low compared with those for wild-type plants. The result shows that ADAP is necessary for the response to stress induced by water deprivation. Together, our data indicate that ADAP is a positive regulator of the ABA response and is also involved in regulating seedling growth. The role of ADAP is similar to that of ARIA, which is also a positive regulator of the ABA response. It appears that ADAP acts through the same ABA response pathway as ARIA.

Identification of Three Positive Regulators in the Geldanamycin PKS Gene Cluster of Streptomyces hygroscopicus JCM4427

  • Kim, Won-Cheol;Lee, Jung-Joon;Paik, Sang-Gi;Hong, Young-Soo
    • Journal of Microbiology and Biotechnology
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    • v.20 no.11
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    • pp.1484-1490
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    • 2010
  • In the Streptomyces hygroscopicus JCM4427 geldanamycin biosynthetic gene cluster, five putative regulatory genes were identified by protein homology searching. Among those genes, gel14, gel17, and gel19 are located downstream of polyketide synthase genes. Gel14 and Gel17 are members of the LAL family of transcriptional regulators, including an ATP/GTP-binding domain at the N-terminus and a DNA-binding helix-turn-helix domain at the C-terminus. Gel19 is a member of the TetR family of transcriptional regulators, which generally act to repress transcription. To verify the biological significance of the putative regulators in geldanamycin production, they were individually characterized by gene disruption, genetic complementation, and transcriptional analyses. All three genes were confirmed as positive regulators of geldanamycin production. Specifically, Gel17 and Gel19 are required for gel14 as well as gelA gene expression.

An Improved Control Strategy Using a PI-Resonant Controller for an Unbalanced Stand-Alone Doubly-Fed Induction Generator

  • Phan, Van-Tung;Lee, Hong-Hee;Chun, Tae-Won
    • Journal of Power Electronics
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    • v.10 no.2
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    • pp.194-202
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    • 2010
  • The main cause of degradation in an unbalanced stand-alone doubly-fed induction generator (DFIG) system is negative sequence components that exist in the generated stator voltages. To eliminate these components, a hybrid current controller composed of a proportional-integral controller and a resonant regulator is developed in this paper. The proposed controller is applied to the rotor-side converter of a DFIG system for the purpose of compensating the negative stator voltage sequences. The proposed current controller is implemented in a single positive rotating reference frame and therefore the controller can directly regulate both the positive and negative sequence components without the need for sequential decomposition of the measured rotor currents. In terms of compensation capability and accuracy, simulations and experimental results demonstrated the excellent performance of the proposed control method when compared to conventional vector control schemes.

E-Commerce Performance Based on Knowledge Management and Organizational Innovativeness

  • LESTARI, Setyani Dwi;MUHDALIHA, Eryco;PUTRA, Aditya Halim Perdana Kusuma
    • Journal of Distribution Science
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    • v.18 no.2
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    • pp.49-58
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    • 2020
  • Purpose: This study focuses on the performance of the strategy of Indonesia's companies in facing the development of e-commerce business. The relationship between Knowledge Management (Organizational Memory, Knowledge Sharing, Knowledge Absorption, Knowledge Acceptance), Organizational Innovativeness, Competitive Advantage (Time, Quality, Cost, Flexibility) and E-Commerce (Humanistic Factors: Management, Competence, Organizational Structures) examined in this case study. Research design, data, and methodology: This study uses two types such us qualitative and quantitative. A survey approach were conducted to collect data from the Group of Companies (Director and Manager), Academician (Lecturer), Regulator (Head of Government Institution Division), and Master of Management (at least five years). Total of 114 samples was collected and processed for statistical analysis using Smart PLS. Results: This study provide the findings proved that Knowledge Management and Organization Innovativeness simultaneously have positive influence on Competitive Advantage, while Knowledge Management, Organization Innovativeness, and Competitive Advantage simultaneously have positive influence on E-commerce where Competitive Advantage positively influence to E-commerce. Conclusions: The implementation of strategies or steps in this study are expected to steer and motivate an organization to successfully implement a good knowledge management system to pass on knowledge from generation to generation in the company Organizational Innovativeness strategies to improve e-commerce performance.

MicroRNA-146a Enhances Helicobacter pylori Induced Cell Apoptosis in Human Gastric Cancer Epithelial Cells

  • Wu, Kai;Yang, Liu;Li, Cong;Zhu, Chao-Hui;Wang, Xin;Yao, Yi;Jia, Yu-Jie
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.14
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    • pp.5583-5586
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    • 2014
  • Helicobacter pylori (H. pylori) infection induces apoptosis in gastric epithelial cells, and this occurrence may link to gastric carcinogenesis. However, the regulatory mechanism of H. pylori-induced apoptosis is not clear. MicroRNA-146a has been implicated as a key regulator of the immune system. This report describes our discovery of molecular mechanisms of microRNA-146a regulation of apoptosis in human gastric cancer cells. We found that overexpression of microRNA-146a by transfecting microRNA-146a mimics could significantly enhance apoptosis, and this upregulation was triggered by COX-2 inhibition. Furthermore, we found that microRNA-146a density was positively correlated with apoptosis rates in H. pylori-positive gastric cancer tissues and intratumoral microRNA-146a density was negatively correlated with lymph node metastasis among H. pylori-positive gastric cancer patients. Understanding the important roles of microRNA-146a in regulating cell apoptosis in H. pylori infected human gastric cancer cells will contribute to the development of microRNA targeted therapy in the future.

Expression of caveolin-3 as positive intracellular signaling regulator on the development of hypertrophy in cardiac tissues

  • Kim, Joo-Heon;Han, Jin;Kim, Yong-Kwon;Yang, Young-Ae;Hong, Yonggeun
    • Korean Journal of Veterinary Research
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    • v.45 no.4
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    • pp.537-544
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    • 2005
  • We have examined distribution and expression of caveolin-3 (cav-3), one of three caveolin isoforms from 16-wks-old spontaneously hypertensive rats (SHR) compared with age-matched control wistar-kyoto (WKY) rats. The expression of cav-3 was increased, whereas expression of PKB/Akt and calcineurin (Cn) was not changed in cardiac tissues of SHR compared to WKY rats. Interestingly, expression of cav-3, PKB/Akt and Cn were decreased in plasma membrane fraction in SHR compared to WKY rats. In H9c2 cardiomyoblast cells treated with phenylephrine ($50{\mu}M$, 48hr) or isoproterenol ($10{\mu}M$, 48hr), the expression of cav-3 was markedly enhanced compared to nontreated cells. Upon immunofluorescence analysis, cav-3 was localized in plasma membrane of control H9c2 cells. However phenylephrine or isoproterenol treatment caused translocation of cav-3 to perinuclear region. These results suggest that cav-3 plays as positive regulators in the development of hypertrophy in cardiac tissues of SHR rats.

Effects of Vanadate on the Calcium Flux of Cardiac Muscle (Vanadate가 심근막을 통한 $Ca^{++}$의 유입 및 유출에 미치는 영향)

  • Park, Young-Shick;Ahn, Duck-Sun;Kang, Doo-Hee
    • The Korean Journal of Physiology
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    • v.20 no.2
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    • pp.175-183
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    • 1986
  • Since it was proposed that vanadate may be an ‘ideal endogenous regulator of the $Na^+,\;K^+-ATPase$ activity (Cantley et at, 1979), vanadate has been a subject of intensive research and a variety of its physiological effects have been described (Nechay, 1984). In isolated guinea pig heart muscle vanadate shows a positive inotropic effect on ventricular muscle, while it induces a negative inotropic effect on atrial muscle. But its underlying mechanism has not been elucidated so far. Therefore, in this study the flux rates of calcium ion into and from guinea pig heart muscle were measured to throw some light on the underlying mechanism, because those rates have been known to be closely related to the cardiac contractility and the results are summarized as follows: 1) Calcium efflux rates from the intracellular $Ca^{++}$ pool (compartment 4) of both guinea pig left atrium and right ventricle were significantly reduced by vanadate and their pool sizes were significantly increased by vanadate. 2) The magnitude of calcium influx into left atrium was reduced by vanadate, While the magnitude of calcium influx into right ventricle was not affected by vanadate. From these results, it may be concluded that the positive inotropic effect of vanadate on the ventricular muscle was due to a reduced efflux rate of calcium ion and its negative inotropic effect on atrial muscle was resulted from a reduced influx of calcium ion.

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The Role of Endothelin-1 in Obstructive Sleep Apnea Syndrome and Pulmonary Hypertension (폐쇄성 수면 무호흡 증후군과 폐동맥 고혈압에서 엔도텔린-1의 역할)

  • Choi, Young-Mi
    • Sleep Medicine and Psychophysiology
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    • v.17 no.2
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    • pp.69-74
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    • 2010
  • Obstructive sleep apnea syndrome is associated with significant cardiovascular morbidity and increased mortality. However, it was controversial whether obstructive sleep apnea syndrome could cause pulmonary hypertension. The controversy was resolved by several studies that have shown pulmonary hypertension in 20% to 40% of patients with obstructive sleep apnea syndrome without underlying other cardiopulmonary diseases and reductions in pulmonary arterial pressure in patients with obstructive sleep apnea syndrome after treatment with nocturnal continuous positive airway pressure. Recent studies provide strong evidence for endothelial dysfunction in obstructive sleep apnea syndrome and pulmonary hypertension. Endothelin-1 is a 21 amino acid peptide with diverse biologic activity such as highly potent vasoconstrictor and mitogen regulator that may play a key role in obstructive sleep ap-nea syndrome and pulmonary hypertension. Continuous positive airway pressure therapy is moderately effective in reducing pulmonary arterial pressure. Further researches are needed to assess the therapeutic efficacy of pharmacologic therapy with agents that inhibit the action of endothelin-1 in obstructive sleep apnea syndrome patients with pulmonary hypertension.

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Development of Soluble Epoxide Hydrolase Inhibitor Screening Methods for Discovery of Drug Candidate in Cardiovascular Diseases (심혈관계 질환 치료제 후보물질 발굴을 위한 Soluble Epoxide Hydrolase 억제평가 방법 개발)

  • Lee, Gwan-Ho;Kim, Bong-Hee;Kim, Sang-Kyum
    • YAKHAK HOEJI
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    • v.56 no.1
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    • pp.42-47
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    • 2012
  • Soluble epoxide hydrolase (sEH) is a metabolic regulator of epoxyeicosatrienoic acids (EETs). EETs have many beneficial effects, vasodilation, anti-diabetes, anti-inflammation, cardiovascular protection, renal protection. Therefore, selective sEH inhibitors have a potential for treating these diseases. In the present study, screening methods for sEH inhibitors using PHOME ((3-phenyl-oxiranyl)-acetic acid cyano-(6-methoxynaphthalen-2-yl)-methyl ester) and 14-15-EET as substrates were established. To determine selectivity, microsomal epoxide hydrolase (mEH) inhibition assay was also developed using styrene oxide as a substrate of microsomal epoxide hydrolase. Our results obtained from 12-[[(tricyclo[3.3.1.13,7]dec-1-ylamino)carbonyl]amino]-dodecanoic acid (AUDA) used as a positive sEH inhibitor and valpromide used as a positive mEH inhibitor showed that these methods are useful for discovery of drug candidates.