• Title/Summary/Keyword: stage-specific activity

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Regulation of Glycogen Concentration by the Histidine-Containing Phosphocarrier Protein HPr in Escherichia coli

  • Koo, Byung-Mo;Seok, Yeong-Jae
    • Journal of Microbiology
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    • v.39 no.1
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    • pp.24-30
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    • 2001
  • In addition to effecting the catalysis of sugar uptake, the bacterial phosphoenolpyruvate::sugar phosphotransferase system regulates a variety of physiological processes. In a previous paper [Seok et al.,(1997) J. Biol. Chem. 272, 26511-26521], we reported the interaction with and allosteric regulation of Esiherichia coli glycogen phosphorylase activity by the histidine-containing phosphocarrier protein HPr in vitro. Here, we show that the specific interaction between HPr and glycogen phosphorylase occurs in vivo. To address the physiological role of the HPr-glycogen phosphorylase complex, intracellular glycogen levels were measured in E. coli strains transformed with various plasmids. While glycogen accumulated during the transition between exponential and stationary growth phases in wildtype cells, it did not accumulate in cells overproducing HPr or its inactive mutant regardless of the growth stage. From these results, we conclude that HPr mediates crosstalk between sugar uptake through the phosphoenolpyruvate:sugar phosphotransferase system and glycogen breakdown. The evolutionary significance of the HPr-glycogen phosphorylase complex is suggested.

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Esterase Isozyme Banding Pattern in Legume Seedings (콩과 식물의 Seeding Esterase Isozyme Banding Pattern에 관한 연구)

  • 이성규
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.11 no.3
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    • pp.158-161
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    • 1991
  • Horizontal starch gel electrophoresis, follow by enzyrne-specific staining, separate and visualize several legume esterase isozyme. Using extracts prepared from cotyledon, radicle and plumule of legume seedlings germinated 5 days. The results were as follows. 1. The number and staining intensity of esterase isozyme bands varies depending on the plant species. tissues and developmental stage. 2. Bands in the cotyledon of field bean seedling expressed 4 and 1 in radicle. 3. In soybean cultivars, cotyledon of IIwangkum-kong had 3 bands and 1 band in the examined tissues of Paldal-kong and Jangkyung-kong seedling. 4. The cotyledon and radicle of french bean seedling had 3 bands, respectively. 5. The highest esterase isozyme activity appears to be expressed in the cotyledon and radicle of french bean, as indicated by intensity of stain, with the Paldal-kong particulary active.

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Gene Transfer and Transient Expression of Foreign DNA in Limanda Yokohamae

  • Yoon, Yoon-Kwon
    • Journal of Aquaculture
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    • v.12 no.4
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    • pp.275-281
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    • 1999
  • The utility of RSV-LTR and carp beta-actin promoters was evaluated in a marine flatfish species, Limanda Yokohamae by examining successful expression of transgenic DNA in muscles (transfected by direct injection) and in early embryos (transformed by lipofected sperm). The expressed pattern of injected DNA in skeletal muscles was dependent on the DNA amount injected. The activity reached to maximal level at 48 hours post injection, and persisted up ot 1 month transiently. Gene transfer into early embryo of this species was successfully achieved using lipofected sperm with the efficiency ranging 36.8% to 48.1%. The expression of transgene during embryonic development was shown as stage-specific and transient.

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Intellectural Property Rights and Innovation: Evidence from EPO Patenting Data (특허권강화는 기술혁신에 대한 유효한 인센티브인가? EPO 특허자료를 중심으로)

  • Seo, Hwan-Joo;Ahn, Jung-Hwa
    • Journal of Technology Innovation
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    • v.12 no.3
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    • pp.49-71
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    • 2004
  • Using panel data, this paper investigates the impacts of the strengthening of intellectual property rights (IPRs) on innovative activity. The estimation results indicate the following important implications. First, IPRs alone do not play a significant role. Second, the effect of IPRs is strong and significant only when it is interacted with complementary environments for innovation. This finding suggests that IPRs play a significant role only via a specific channel of interaction such as the stage of economic development, institutional environment and trade openness. Third, the significant correlation is not identical across countries implying that some countries were positively affected while others were negatively affected. Those countries are identified as well.

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Molecular mechanisms and therapeutic interventions in sarcopenia

  • Park, Sung Sup;Kwon, Eun-Soo;Kwon, Ki-Sun
    • Osteoporosis and Sarcopenia
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    • v.3 no.3
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    • pp.117-122
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    • 2017
  • Sarcopenia is the degenerative loss of muscle mass and function with aging. Recently sarcopenia was recognized as a clinical disease by the International Classification of Disease, 10th revision, Clinical Modification. An imbalance between protein synthesis and degradation causes a gradual loss of muscle mass, resulting in a decline of muscle function as a progress of sarcopenia. Many mechanisms involved in the onset of sarcopenia include age-related factors as well as activity-, disease-, and nutrition-related factors. The stage of sarcopenia reflecting the severity of conditions assists clinical management of sarcopenia. It is important that systemic descriptions of the disease conditions include age, sex, and other environmental risk factors as well as levels of physical function. To develop a new therapeutic intervention needed is the detailed understanding of molecular and cellular mechanisms by which apoptosis, autophagy, atrophy, and hypertrophy occur in the muscle stem cells, myotubes, and/or neuromuscular junction. The new strategy to managing sarcopenia will be signal-modulating small molecules, natural compounds, repurposing of old drugs, and muscle-specific microRNAs.

Antibody-based Screening of Porphyromonas gingivalis Proteins Specifically Produced in Patients with Chronic Periodontitis

  • Kim, Hye-Jung;Lee, Seok-Woo
    • International Journal of Oral Biology
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    • v.43 no.4
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    • pp.201-207
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    • 2018
  • Porphyromonas gingivalis is among the major etiological pathogens of chronic periodontitis. The virulence mechanisms of P. gingivalis is yet to be identified as its activity is largely unknown in actual disease process. The purpose of this study is to identify antigens of P. gingivalis expressed only in patients with chronic periodontitis using a unique immunoscreening technique. Change Mediated Antigen Technology (CMAT), an antibody-based screening technique, was used to identify virulence-associated proteins of P. gingivalis that are expressed only during infection stage in patients having chronic periodontitis. Out of 13,000 recombinant clones screened, 22 tested positive for reproducible reactivity with rabbit hyperimmune anti-sera prepared against dental plaque samples acquired from periodontitis patients. The DNA sequences of these 18 genes were determined. CMAT-identified protein antigens of P. gingivalis included proteins involved in energy metabolism and biosynthesis, heme and iron binding, drug resistance, specific enzyme activities, and unknown functions. Further analysis of these genes could result in a novel insight into the virulence mechanisms of P. gingivalis.

Learning Analytics Framework on Metaverse

  • Sungtae LIM;Eunhee KIM;Hoseung BYUN
    • Educational Technology International
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    • v.24 no.2
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    • pp.295-329
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    • 2023
  • The recent development of metaverse-related technology has led to efforts to overcome the limitations of time and space in education by creating a virtual educational environment. To make use of this platform efficiently, applying learning analytics has been proposed as an optimal instructional and learning decision support approach to address these issues by identifying specific rules and patterns generated from learning data, and providing a systematic framework as a guideline to instructors. To achieve this, we employed an inductive, bottom-up approach for framework modeling. During the modeling process, based on the activity system model, we specifically derived the fundamental components of the learning analytics framework centered on learning activities and their contexts. We developed a prototype of the framework through deduplication, categorization, and proceduralization from the components, and refined the learning analytics framework into a 7-stage framework suitable for application in the metaverse through 3 steps of Delphi surveys. Lastly, through a framework model evaluation consisting of seven items, we validated the metaverse learning analytics framework, ensuring its validity.

Antitumor Activity and Effect on Cell Proliferation and Differenciation of Exopolysaccharide Produced by Submerged Cultivation of Ganoderma lucidum (영지(Ganoderma lucidum)의 액체배양에 의한 세포외 다당의 항암활성과 세포증식 및 분화에 미치는 영향)

  • Lee, Shin-Young;Kang, Tae-Su;Moon, Soon-Ok
    • Journal of Industrial Technology
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    • v.25 no.B
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    • pp.241-251
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    • 2005
  • Exopolysaccharide (CBP) from submerged culture broth of Ganoderma lucidum mycelium and the water soluble (BWS) and water insoluble (BWI) fractions of CBP were prepared by gel filtration. Antitumor activity and effects on proliferation and differenciation of human cancer cells and mouse NIH 3T3 cells were studied. Cytotoxicity test of CBP, BWS and BWI fractions on human cancer cell lines was performed by using sulforhodamine B (SRB) assay. A549 (lung carcinoma), Colo320 DM and HSR (colon carcinoma), and NIH 3T3 cells were used. BWI fraction showed the strongest cytotoxicity (maximum 20% survival) to all human cells tested. However it did not induced apoptosis. Interestingly BWI fraction did not exert cytotoxic effect on NIH 3T3 cells at low concentration of cells ($5{\times}10^4$) but strong toxic effect at high concentration of cells($5{\times}10^5$) which showed transformed morphology. These results suggest that BWI may have cancer cell specific anticancer activity. However, BWI fraction did not effect the amount of pRb and c-myc protein, which implied that BWI fraction did not act at the early stage of signal transduction pathway. CBP fraction induced differenciation of human leukemic cell line, HL-60 cells suggesting the carcinogenesis prevention of normal cell and possible induction of normalization for cancer cell.

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The Inactivation of ERK1/2, p38 and NF-kB Is Involved in the Down-Regulation of Osteoclastogenesis and Function by A2B Adenosine Receptor Stimulation

  • Kim, Bo Hyun;Oh, Ju Hee;Lee, Na Kyung
    • Molecules and Cells
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    • v.40 no.10
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    • pp.752-760
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    • 2017
  • A2B adenosine receptor (A2BAR) is known to be the regulator of bone homeostasis, but its regulatory mechanisms in osteoclast formation are less well-defined. Here, we demonstrate the effect of A2BAR stimulation on osteoclast differentiation and activity by RANKL. A2BAR was expressed in bone marrow-derived monocyte/macrophage (BMM) and RANKL increased A2BAR expression during osteoclastogenesis. A2BAR stimulation with its specific agonist BAY 60-6583 was sufficient to inhibit the activation of ERK1/2, p38 MAP kinases and $NF-{\kappa}B$ by RANKL as well as it abrogated cell-cell fusion in the late stage of osteoclast differentiation. Stimulation of A2BAR suppressed the expression of osteoclast marker genes, such as c-Fos, TRAP, Cathepsin-K and NFATc1, induced by RANKL, and transcriptional activity of NFATc1 was also inhibited by stimulation of A2BAR. A2BAR stimulation caused a notable reduction in the expression of Atp6v0d2 and DC-STAMP related to cell-cell fusion of osteoclasts. Especially, a decrease in bone resorption activity through suppression of actin ring formation by A2BAR stimulation was observed. Taken together, these results suggest that A2BAR stimulation inhibits the activation of ERK1/2, p38 and $NF-{\kappa}B$ by RANKL, which suppresses the induction of osteoclast marker genes, thus contributing to the decrease in osteoclast cell-cell fusion and bone resorption activity.

Changes in Gibberellin Hydroxylase Activity during Seed Maturation of Phaseolus vulgaris L. II. C20-Hydroxylase Converting $GA_{12} to GA_{15}$ (강낭콩(Phaseolus vulgaris L.) 종자성숙에 따른 지베렐린 수산화효소 활성의 변화 II. $GA_{12}$를\; $GA_{15}$으로 변환하는 C20-Hydroxylase)

  • 정상수
    • Journal of Plant Biology
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    • v.35 no.3
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    • pp.191-195
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    • 1992
  • Changes in activity of gibberellin C20-hydroxylase which converts $[^{14}C]GA_{12}\;to\;GA_{l5}$ were studied during seed maturation using the partially purified enzyme preparations of two cultivars, Kentucky Wonder (normal) and Masterpiece (dwarf) of Phaseolus vulgaris. The preparations obtained by methanol precipitation and hydrophobic interaction chromatography efficiently converted; $GA_{l2}\;to\;GA_{4},\;via\;GA_{15},\;GA_{24}\;and\;GA_{9};\;GA_{20}\;to\;GA_{1},\;GA_{5}\;and\;GA_{6}$. The activities of C20-hydroxylase which converts $GA_{l2}\;to\;GA_{l5}$ were almost the same in both cultivars. The C20-hydroxylase activity per protein reached a maximum at the very early immature seed stage, followed by a subsequent rapid decrease during seed maturation, whereas the enzyme specific activity per seed reached a maximum at 21 days after flowering, and showed a similar fiuctuation to that of the 313-hydroxylase which converts $GA_{20}\;to\;GA_{l}$ during seed maturation.ration.

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