• Title/Summary/Keyword: expression dynamics

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Recombinant Expression, Isotope Labeling, and Purification of Cold shock Protein from Colwellia psychrerythraea for NMR Study

  • Moon, Chang-Hun;Jeong, Ki-Woong;Kim, Hak-Jun;Heo, Yong-Seok;Kim, Yang-Mee
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2647-2650
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    • 2009
  • Cold shock proteins (Csps) are a subgroup of the cold-induced proteins on reduction of the growth temperature below the physiological temperature. They preferentially bind to single-stranded nucleic acids to translational regulation via RNA chaperoning. Csp plays important role in cold adaptations for the psychrophilic microorganism. Recently, Cold shock protein from psychrophilic bacteria, Colwellia psychrerythraea (CpCsp) has been identified. Three dimensional structures of a number of Csps from various microorganisms have been solved by NMR spectroscopy or X-ray crystallography, but structures of psychrophilic Csps were not studied yet. Therefore, cloning and purification protocols for further structural study of psychrophilic Csp have been optimized in this study. CpCsp was expressed in E. coli with pET-11a vector system and purified by ion exchange, size exclusion, and reverse phase chromatography. Expression and purification of CpCsp in M9 minimal media was carried out and $^{15}N$-labeled proteins with high purity over 90% was obtained. Further study will be carried out to investigate the tertiary structure and dynamics of CpCsp.

A Study on the Trend Analysis on the Hypertext Representation of the Museum Space (전시공간의 하이퍼텍스트적 표현 경향 분석에 관한 연구)

  • Kim, Ji-In;Yoon, Gab-Geun
    • Korean Institute of Interior Design Journal
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    • v.18 no.1
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    • pp.64-71
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    • 2009
  • The modern society is rapidly changing through the development of computer network technology. By generation a collapse of boundaries between may important social institutions, computer networking has affected culture, economy and the physical environment. Because of this, people face a switchover from a simple society, to a compound society. It will also increase the diversity if society's demand, though, and experience. This change is not an exception in the exhibition space. People are more interested in civilized pastimes and also demand diverse thinking. So as a necessary consequence, the function of museum space Is offended and that there are various attempt to increase information and demand of that space. The purpose of this study is try to find a solution a countermeasure of modern society's mobile situation. Researchers analyzed structural qualities of Hyper-text; non-boundary, interaction and nonlinear and deduce nine kinds of methods to apply in space. Also, Researchers looked at the examples in museum space and derived like this expression way; dynamics, mobility, a non-materiality, continuity, complexity from analysis of expression way.

Interrelation among Weather, Agriculture and People's Life, and Policy in a Local in the Late Choson : In Case of "Goseong Chongswaerok" by O Hoeng-muk (조선후기 지방의 날씨, 농사.주민의 삶, 정책의 상호관계 : 오횡묵의 "고성총쇄록(固城叢瑣錄)"을 사례로)

  • Park, Kyu-Taeg
    • Journal of the Korean association of regional geographers
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    • v.16 no.3
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    • pp.224-248
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    • 2010
  • This study is to analyze the Korean translation of "Goseong Chongswaerok" by O Hoeng-muk as a local governor through political ecology. It focuses on how O Hoeng-muk recognized and wrote the interrelation among weather, agriculture, local resident's life, and local policy. The results are summarized in the followings. Firstly, weather was recorded into three types of expression, simple and dynamic expression and agriculture-related expression. Its dynamics was much meaningful and important when weather was related to local resident's life and local or non-local economy and politics. Secondly, weather and local government were conflict under a particular natural condition like severe drought. And society and politics are affected by such a conflict. Thirdly, local people's demonstration was occurred under a certain condition. Bounded agency can be founded in O Hoeng-muk's behavior as a local governor like jinhyul(賑恤), rain rituals, tax collection. Fourthly, the interrelation among weather, agriculture, local people's life, and local policy implemented in a particular local like Goseong ought to be interpreted in terms of multiple scales.

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Temporal Expression of RNA Polymerase II in Porcine Oocytes and Embryos

  • Oqani, Reza;Lee, Min Gu;Tao, Lin;Jin, Dong Il
    • Reproductive and Developmental Biology
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    • v.36 no.4
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    • pp.237-241
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    • 2012
  • Embryonic genome activation (EGA) is the first major transition that occurs after fertilization, and entails a dramatic reprogramming of gene expression that is essential for continued development. Although it has been suggested that EGA in porcine embryos starts at the four-cell stage, recent evidence indicates that EGA may commence even earlier; however, the molecular details of EGA remain incompletely understood. The RNA polymerase II of eukaryotes transcribes mRNAs and most small nuclear RNAs. The largest subunit of RNA polymerase II can become phosphorylated in the C-terminal domain. The unphosphorylated form of the RNA polymerase II largest subunit C-terminal domain (IIa) plays a role in initiation of transcription, and the phosphorylated form (IIo) is required for transcriptional elongation and mRNA splicing. In the present study, we explored the nuclear translocation, nuclear localization, and phosphorylation dynamics of the RNA polymerase II C-terminal domain in immature pig oocytes, mature oocytes, two-, four-, and eight-cell embryos, and the morula and blastocyst. To this end, we used antibodies specific for the IIa and IIo forms of RNA polymerase II to stain the proteins. Unphosphorylated RNA polymerase II stained strongly in the nuclei of germinal vesicle oocytes, whereas the phosphorylated form of the enzyme was confined to the chromatin of prophase I oocytes. After fertilization, both unphosphorylated and phosphorylated RNA polymerase II began to accumulate in the nuclei of early stage one-cell embryos, and this pattern was maintained through to the blastocyst stage. The results suggest that both porcine oocytes and early embryos are transcriptionally competent, and that transcription of embryonic genes during the first three cell cycles parallels expression of phosphorylated RNA polymerase II.

A Discrete Mathematical Model Applied to Genetic Regulation and Metabolic Networks

  • Asenjo, J.A.;Ramirez, P.;Rapaport, I.;Aracena, J.;Goles, E.;Andrews, B.A.
    • Journal of Microbiology and Biotechnology
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    • v.17 no.3
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    • pp.496-510
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    • 2007
  • This paper describes the use of a discrete mathematical model to represent the basic mechanisms of regulation of the bacteria E. coli in batch fermentation. The specific phenomena studied were the changes in metabolism and genetic regulation when the bacteria use three different carbon substrates (glucose, glycerol, and acetate). The model correctly predicts the behavior of E. coli vis-a-vis substrate mixtures. In a mixture of glucose, glycerol, and acetate, it prefers glucose, then glycerol, and finally acetate. The model included 67 nodes; 28 were genes, 20 enzymes, and 19 regulators/biochemical compounds. The model represents both the genetic regulation and metabolic networks in an integrated form, which is how they function biologically. This is one of the first attempts to include both of these networks in one model. Previously, discrete mathematical models were used only to describe genetic regulation networks. The study of the network dynamics generated 8 $(2^3)$ fixed points, one for each nutrient configuration (substrate mixture) in the medium. The fixed points of the discrete model reflect the phenotypes described. Gene expression and the patterns of the metabolic fluxes generated are described accurately. The activation of the gene regulation network depends basically on the presence of glucose and glycerol. The model predicts the behavior when mixed carbon sources are utilized as well as when there is no carbon source present. Fictitious jokers (Joker1, Joker2, and Repressor SdhC) had to be created to control 12 genes whose regulation mechanism is unknown, since glycerol and glucose do not act directly on the genes. The approach presented in this paper is particularly useful to investigate potential unknown gene regulation mechanisms; such a novel approach can also be used to describe other gene regulation situations such as the comparison between non-recombinant and recombinant yeast strain, producing recombinant proteins, presently under investigation in our group.

Molecular Dynamics Simulation Study for Ionic Strength Dependence of RNA-host factor Interaction in Staphylococcus aureus Hfq

  • Lazar, Prettina;Lee, Yun-O;Kim, Song-Mi;Chandrasekaran, Meganathan;Lee, Keun-Woo
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1519-1526
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    • 2010
  • The behavior of peptide or protein solutes in saline aqueous solution is a fundamental topic in physical chemistry. Addition of ions can strongly alter the thermodynamic and physical properties of peptide molecules in solution. In order to study the effects of added ionic salts on protein conformation and dynamics, we have used the molecular dynamics (MD) simulations to investigate the behavior of Staphylococcus aureus Hfq protein under two different ionic concentrations: 0.1 M NaCl and 1.0 M NaCl in presence and absence of RNA (a hepta-oligoribonucleotide AU5G). Hfq, a global regulator of gene expression is highly conserved and abundant RNA-binding protein. It is already reported that in vivo the increase of ionic strength results in a drastic reduction of Hfq affinity for $Q{\beta}$ RNA and reduces the tendency of aggregation of Escherichia coli host factor hexamers. Our results revealed the crucial role of 0.1 M NaCl Hfq system on the bases with strong hydrogen bonding interactions and by stabilizing the aromatic stacking of Tyr42 residue of the adjacent subunits/monomers with the adenine and uridine nucleobases. An increase in RNA pore diameter and weakened compactness of the Hfq-RNA complex was clearly observed in 1.0 M NaCl Hfq system with bound RNA. Aggregation of monomers in Hfq and the interaction of Hfq with RNA are greatly affected due to the presence of high ionic strength. Higher the ionic concentration, weaker is the aggregation and interaction. Our results were compatible with the experimental data and this is the first theoretical report for the experimental study done in 1980 by Uhlenbeck group for the present system.

Respiratory Syncytial Virus (RSV) Modulation at the Virus-Host Interface Affects Immune Outcome and Disease Pathogenesis

  • Tripp, Ralph A.
    • IMMUNE NETWORK
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    • v.13 no.5
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    • pp.163-167
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    • 2013
  • The dynamics of the virus-host interface in the response to respiratory virus infection is not well-understood; however, it is at this juncture that host immunity to infection evolves. Respiratory viruses have been shown to modulate the host response to gain a replication advantage through a variety of mechanisms. Viruses are parasites and must co-opt host genes for replication, and must interface with host cellular machinery to achieve an optimal balance between viral and cellular gene expression. Host cells have numerous strategies to resist infection, replication and virus spread, and only recently are we beginning to understand the network and pathways affected. The following is a short review article covering some of the studies associated with the Tripp laboratory that have addressed how respiratory syncytial virus (RSV) operates at the virus-host interface to affects immune outcome and disease pathogenesis.

Proteome Analysis of Recombinant CHO Cells Under Hyperosmotic Stress

  • Lee, Mun-Su;Kim, Gyeong-Uk;Kim, Yeong-Hwan;Lee, Gyun-Min
    • 한국생물공학회:학술대회논문집
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    • 2003.04a
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    • pp.311-314
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    • 2003
  • Under hyperosmotic stress, rCHO cells display decreased specific growth rate $({\mu})$ and increased specific antibody productivity $(q_{Ab})$. The effects of hyperosmotic stress on batch culture cellular dynamics are not well understood. To this end, we conducted a proteome profile of rCHO cells, using 2D-gel, MALDI-TOF-MS and MS/MS. As a result, the proteome profile of rCHO cells could be established using 41 identified proteins. Based on this proteome profile of rCHO cells, we have found at least 8 differently expressed spots at hyperosmotic osmolality (450 mOsm/kg). Among these spots, two metabolic enzymes were found to be up-regulated (pyruvate kinase and GAPDH), while down-regulated protein was identified as tubulin. It shows that hyperosmotic stress can alter metabolic state, by up-regulated activities of two glycolysis enzymes, which could lead to activate the generation of metabolic energy. Tubulin expression was down-regulated, suggesting a reduction of cell division. Finally, the increased conversion energy could leads to improve overall productivity.

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State-Space Approach to Modeling Dynamics of Gene Regulation in Networks

  • Xiong, Momiao;Jin, Li
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2005.09a
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    • pp.191-196
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    • 2005
  • Genetic networks are a key to unraveling dynamic properties of biological processes and regulation of genes plays an essential role in dynamic behavior of the genetic networks. A popular characterization of regulation of the gene is a kinetic model. However, many kinetic parameters in the genetic regulation have not been available. To overcome this difficulty, in this report, state-space approach to modeling gene regulation is presented. Second-order systems are used to characterize gene regulation. Interpretation of coefficients in the second order systems as resistance, capacitance and inductance is studied. The mathematical methods for transient response analysis of gene regulation to external perturbation are investigated. Criterion for classifying gene into three categories: underdamped, overdamped and critical damped is discussed. The proposed models are applied to yeast cell cycle gene expression data.

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A simple and rapid approach to modeling chromium breakthrough in fixed bed adsorber

  • Chu, Khim Hoong
    • Advances in environmental research
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    • v.7 no.1
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    • pp.29-37
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    • 2018
  • A simple mathematical model for predicting fixed bed adsorption dynamics is described. The model is characterized by a linear adsorption isotherm and a linear driving force expression for mass transfer. Its analytic solution can be approximated with an algebraic equation in closed form which is easily evaluated by spreadsheet computation. To demonstrate one application of the fixed bed model, a previously published adsorption system is used as a case study in this work. The adsorption system examined here describes chromium breakthrough in a fixed bed adsorber packed with imidazole functionalized adsorbent particles and is characterized by a nonlinear adsorption isotherm. However, the equilibrium behavior of the fixed bed adsorber is in essence governed by a linear adsorption isotherm due to the use of a low influent chromium concentration. It is shown that chromium breakthrough is predicted reasonably well by the fixed bed model. The model's parameters can be easily extracted from independent batch experiments. The proposed modeling approach is very simple and rapid, and only Excel is used for computation.