• Title/Summary/Keyword: Genome Analysis

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Notch Signal Transduction Induces a Novel Profile of Kaposi's Sarcoma-Associated Herpesvirus Gene Expression

  • Chang Hee-Soon
    • Journal of Microbiology
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    • v.44 no.2
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    • pp.217-225
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    • 2006
  • Kaposi's sarcoma-associated herpesvirus (KSHV) RTA transcription factor is recruited to its responsive elements through interaction with RBP-Jk that is a downstream transcription factor of the Notch signaling pathway that is important in development and cell fate determination. This suggests that KSHV RTA mimics cellular Notch signal transduction to activate viral lytic gene expression. Here, I demonstrated that unlike other B lymphoma cells, KSHV -infected primary effusion lymphoma BCBL1 cells displayed the constitutive activation of ligand-mediated Notch signal transduction, evidenced by the Jagged ligand expression and the complete proteolytic process of Notch receptor I. In order to investigate the effect of Notch signal transduction on KSHV gene expression, human Notch intracellular (hNIC) domain that constitutively activates RBP-Jk transcription factor activity was expressed in BCBL1 cells, TRExBCBL1-hNIC, in a tetracycline inducible manner. Gene expression profiling showed that like RTA, hNIC robustly induced expression of a number of viral genes including KS immune modulatory gene resulting in downregulation of MHC I and CD54 surface expression. Finally, the genetic analysis of KSHV genome demonstrated that the hNIC-mediated expression of KS during viral latency consequently conferred the downregulation of MHC I and CD54 surface expression. These results indicate that cellular. Notch signal transduction provides a novel expression profiling of KSHV immune deregulatory gene that consequently confers the escape of host immune surveillance during viral latency.

Sequencing of the RSDA Gene Encoding Raw Starch-Digesting $\alpha$-Amylase of Bacillus circulans F-2: Identification of Possible Two Domains for Raw Substrate-Adsorption and Substrate-Hydrolysis

  • Kim, Cheorl-Ho
    • Journal of Microbiology and Biotechnology
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    • v.2 no.1
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    • pp.56-65
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    • 1992
  • The complete nucleotide sequence of the Bacillus circulans F-2 RSDA gene, coding for raw starch digesting a-amylase (RSDA), has been determined. The RSDA structure gene consists of an open reading frame of 2508 bp. Six bp upstream of the translational start codon of the RSDA is a typical gram-positive Shine-Dalgarno sequence and the RSDA encodes a preprotein of 836 amino acids with an Mr of 96, 727. The gene was expressed from its own regulatory region in E. coli and two putative consensus promoter sequences were identified upstream of a ribosome binding site and an ATG start codon. Confirmation of the nucleotide sequence was obtained and the signal peptide cleavage site was identified by comparing the predicted amino acid sequence with that derived by N-terminal analysis of the purified RSDA. The deduced N-terminal region of the RSDA conforms to the general pattern for the signal peptides of secreted prokaryotic proteins. The complete amino acid sequence was deduced and homology with other enzymes was compared. The results suggested that the Thr-Ser-rich hinge region and the non-catalytic domain are necessary for efficient adsorption onto raw substrates, and the catalytic domain (60 kDa) is necessary for the hydrolysis of substrates, as suggested in previous studies (8, 9).

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Identification of B52-dependent Gene Expression Signature and Alternative Splicing Using a D. melanogaster B52-null Mutant

  • Hong, Sun-Woo;Jung, Mi-Sun;Kim, Eun-Kyung;Lee, Dong-Ki;Kim, So-Youn
    • Bulletin of the Korean Chemical Society
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    • v.30 no.2
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    • pp.323-326
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    • 2009
  • SR proteins are essential splicing regulators and also modulate alternative splicing events, which function both as redundant and substrate-specific manner. The Drosophila B52/SRp55, a member of the SR protein family, is essential for the fly development in vivo, as deletion of B52 gene results in lethality of animals at the second instar larval stage. Identification of the splicing target genes of B52 thus should be crucial for the understanding of the specific developmental role of B52 in vivo. In this study, we performed whole-genome DNA microarray experiments with a B52- knock-out animal. Analysis of the microarray data not only provided the B52-dependent gene expression signature, but also revealed a larval-stage specific, alternative splicing target gene of B52. Our result thus provides a starting point to understand the essential function of B52 at the organismal level.

Understanding Rifampicin Resistance in Tuberculosis through a Computational Approach

  • Kumar, Satish;Jena, Lingaraja
    • Genomics & Informatics
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    • v.12 no.4
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    • pp.276-282
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    • 2014
  • The disease tuberculosis, caused by Mycobacterium tuberculosis (MTB), remains a major cause of morbidity and mortality in developing countries. The evolution of drug-resistant tuberculosis causes a foremost threat to global health. Most drug-resistant MTB clinical strains are showing resistance to isoniazid and rifampicin (RIF), the frontline anti-tuberculosis drugs. Mutation in rpoB, the beta subunit of DNA-directed RNA polymerase of MTB, is reported to be a major cause of RIF resistance. Amongst mutations in the well-defined 81-base-pair central region of the rpoB gene, mutation at codon 450 (S450L) and 445 (H445Y) is mainly associated with RIF resistance. In this study, we modeled two resistant mutants of rpoB (S450L and H445Y) using Modeller9v10 and performed a docking analysis with RIF using AutoDock4.2 and compared the docking results of these mutants with the wild-type rpoB. The docking results revealed that RIF more effectively inhibited the wild-type rpoB with low binding energy than rpoB mutants. The rpoB mutants interacted with RIF with positive binding energy, revealing the incapableness of RIF inhibition and thus showing resistance. Subsequently, this was verified by molecular dynamics simulations. This in silico evidence may help us understand RIF resistance in rpoB mutant strains.

Analysis of Gene Expression in Cyclooxygenase-2-Overexpressed Human Osteosarcoma Cell Lines

  • Han, Jeong A.;Kim, Ji-Yeon;Kim, Jong-Il
    • Genomics & Informatics
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    • v.12 no.4
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    • pp.247-253
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    • 2014
  • Osteosarcoma is the most common primary bone tumor, generally affecting young people. While the etiology of osteosarcoma has been largely unknown, recent studies have suggested that cyclooxygenase-2 (COX-2) plays a critical role in the proliferation, migration, and invasion of osteosarcoma cells. To understand the mechanism of action of COX-2 in the pathogenesis of osteosarcoma, we compared gene expression patterns between three stable COX-2-overexpressing cell lines and three control cell lines derived from U2OS human osteosarcoma cells. The data showed that 56 genes were upregulated, whereas 20 genes were downregulated, in COX-2-overexpressed cell lines, with an average fold-change > 1.5. Among the upregulated genes, COL1A1, COL5A2, FBN1, HOXD10, RUNX2, and TRAPPC2 are involved in bone and skeletal system development, while DDR2, RAC2, RUNX2, and TSPAN31 are involved in the positive regulation of cell proliferation. Among the downregulated genes, HIST1H1D, HIST1H2AI, HIST1H3H, and HIST1H4C are involved in nucleosome assembly and DNA packaging. These results may provide useful information to elucidate the molecular mechanism of the COX-2-mediated malignant phenotype in osteosarcoma.

The Construction of Regulatory Network for Insulin-Mediated Genes by Integrating Methods Based on Transcription Factor Binding Motifs and Gene Expression Variations

  • Jung, Hyeim;Han, Seonggyun;Kim, Sangsoo
    • Genomics & Informatics
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    • v.13 no.3
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    • pp.76-80
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    • 2015
  • Type 2 diabetes mellitus is a complex metabolic disorder associated with multiple genetic, developmental and environmental factors. The recent advances in gene expression microarray technologies as well as network-based analysis methodologies provide groundbreaking opportunities to study type 2 diabetes mellitus. In the present study, we used previously published gene expression microarray datasets of human skeletal muscle samples collected from 20 insulin sensitive individuals before and after insulin treatment in order to construct insulin-mediated regulatory network. Based on a motif discovery method implemented by iRegulon, a Cytoscape app, we identified 25 candidate regulons, motifs of which were enriched among the promoters of 478 up-regulated genes and 82 down-regulated genes. We then looked for a hierarchical network of the candidate regulators, in such a way that the conditional combination of their expression changes may explain those of their target genes. Using Genomica, a software tool for regulatory network construction, we obtained a hierarchical network of eight regulons that were used to map insulin downstream signaling network. Taken together, the results illustrate the benefits of combining completely different methods such as motif-based regulatory factor discovery and expression level-based construction of regulatory network of their target genes in understanding insulin induced biological processes and signaling pathways.

Standard-based Integration of Heterogeneous Large-scale DNA Microarray Data for Improving Reusability

  • Jung, Yong;Seo, Hwa-Jeong;Park, Yu-Rang;Kim, Ji-Hun;Bien, Sang Jay;Kim, Ju-Han
    • Genomics & Informatics
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    • v.9 no.1
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    • pp.19-27
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    • 2011
  • Gene Expression Omnibus (GEO) has kept the largest amount of gene-expression microarray data that have grown exponentially. Microarray data in GEO have been generated in many different formats and often lack standardized annotation and documentation. It is hard to know if preprocessing has been applied to a dataset or not and in what way. Standard-based integration of heterogeneous data formats and metadata is necessary for comprehensive data query, analysis and mining. We attempted to integrate the heterogeneous microarray data in GEO based on Minimum Information About a Microarray Experiment (MIAME) standard. We unified the data fields of GEO Data table and mapped the attributes of GEO metadata into MIAME elements. We also discriminated non-preprocessed raw datasets from others and processed ones by using a two-step classification method. Most of the procedures were developed as semi-automated algorithms with some degree of text mining techniques. We localized 2,967 Platforms, 4,867 Series and 103,590 Samples with covering 279 organisms, integrated them into a standard-based relational schema and developed a comprehensive query interface to extract. Our tool, GEOQuest is available at http://www.snubi.org/software/GEOQuest/.

Structure and expression analysis of the OsCam1-1 calmodulin gene from Oryza sativa L.

  • Phean-o-pas, Srivilai;Limpaseni, Tipaporn;Buaboocha, Teerapong
    • BMB Reports
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    • v.41 no.11
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    • pp.771-777
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    • 2008
  • Calmodulin (CaM) proteins, members of the EF-hand family of $Ca^{2+}$-binding proteins, represent important relays in plant calcium signals. Here, OsCam1-1 was isolated by PCR amplification from the rice genome. The gene contains an ORF of 450 base pairs with a single intron at the same position found in other plant Cam genes. A promoter region with a TATA box at position-26 was predicted and fused to a gus reporter gene, and this construct was used to produce transgenic rice by Agrobacterium-mediated transformation. GUS activity was observed in all organs examined and throughout tissues in cross-sections, but activity was strongest in the vascular bundles of leaves and the vascular cylinders of roots. To examine the properties of OsCaM1-1, the encoding cDNA was expressed in Escherichia coli. The electrophoretic mobility shift when incubated with $Ca^{2+}$ indicates that recombinant OsCaM1-1 is a functional $Ca^{2+}$-binding protein. In addition, OsCaM1-1 bound the CaMKII target peptide confirming its likely functionality as a calmodulin.

Characterization of a novel Cotesia vestalis polydnavirus (CvBV) gene containing a ser-rich motif expressed in Plutella xylostella larvae

  • Shi, Min;Chen, Ya-Feng;Huang, Fang;Zhou, Xue-Ping;Chen, Xue-Xin
    • BMB Reports
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    • v.41 no.8
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    • pp.587-592
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    • 2008
  • Cotesia vestalis is an endoparasitoid of Plutella xylostella larvae and injects a polydnavirus (CvBV) into its host during oviposition. In this report we characterize the gene, CvBV3307, and its products. CvBV3307 is located on segment S33 of the CvBV genome, is 517 bp, and encodes a putative protein of 122 amino acids, including a serine-rich region. The expression pattern of CvBV3307 in parasitized larvae and the subcellular localization of CvBV3307 only in granulocytes indicated that it might be involved in early protection of parasitoid eggs from host cellular encapsulation and in manipulating the hormone titer and developmental rhythm of host larvae. Western blot analysis showed that the size of the immunoreactive protein (about 55 kDa) in parasitized hosts at 48 hours post parasitization (h p.p.) is much larger than the predicted molecular weight of 13.6 kDa, which suggests that CvBV3307 undergoes extensive post-translational modification in hosts.

Patterns of Diagnosis and Risk Factors for Type 2 Diabetes in Women with a History of Gestational Diabetes Mellitus (임신성 당뇨 과거력을 가진 여성의 2형 당뇨진단 양상과 관련요인)

  • Choi, Mi Jin;Chung, Chae Weon
    • Perspectives in Nursing Science
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    • v.13 no.1
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    • pp.17-28
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    • 2016
  • Purpose: This study aimed to identify patterns of diagnosis and to explore risk factors for type 2 diabetes beyond the postpartum period in women with a previous history of gestational diabetes, and to identify differences in such risk factors between early and late-onset (aged <45 and ${\geq}45$). Methods: Using epidemiological data from the Korean Genome and Epidemiology Study, a retrospective analysis of 175 women with various timings of type 2 diabetes diagnosis was performed. Results: The average age ($42.6{\pm}10.6$) at type 2 diabetes diagnosis was earlier than the general population, and obesity was prevalent with marked weight gains around 35 years old. Longer duration of breastfeeding was observed in women with late-onset of type 2 diabetes. Conclusion: For prevention of type 2 diabetes, early intervention is required, and modifiable factors such as weight control and breastfeeding should be taken into consideration for intervention strategies.