• Title/Summary/Keyword: Gene Screening

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Fission Yeast-based Screening to Identify Putative HDAC Inhibitors Using a Telomeric Reporter Strain

  • Chung, Kyung-Sook;Ahn, Jiwon;Choi, Chung-Hae;Yim, Nam Hui;Kang, Chang-Mo;Kim, Chun-Ho;Lee, Kyeong;Park, Hee-Moon;Song, Kyung-Bin;Won, Misun
    • Molecules and Cells
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    • v.26 no.1
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    • pp.93-99
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    • 2008
  • Transcriptional silencing is regulated by promoter methylation and histone modifications such as methylation and acetylation. We constructed a Schizosaccaromyces pombe reporter strain, KCT120a, to identify modifiers of transcriptional silencing, by inserting the $ura4^+$ gene into a heterochromatic telomere region. Two compounds inhibited the activity of histone deacetylases, induced acetylation of histone H3 and caused apoptotic cell death in HeLa cells. Expression of gelsolin and $p21^{waf1/cip1}$ also increased, as it does in response to HDAC inhibitors such as TSA. Therefore, these compounds appear to be potent inhibitors of HDACs, and hence potential anti-cancer drugs. Our observations suggest that a yeast cell-based assay system for transcriptional silencing may be useful for identifying histone deacetylase inhibitors and other agents affecting chromatin remodeling.

Molecular Characterization of a Novel Vegetative Insecticidal Protein from Bacillus thuringiensis Effective Against Sap-Sucking Insect Pest

  • Sattar, Sampurna;Maiti, Mrinal K.
    • Journal of Microbiology and Biotechnology
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    • v.21 no.9
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    • pp.937-946
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    • 2011
  • Several isolates of Bacillus thuringiensis (Bt) were screened for the vegetative insecticidal protein (Vip) effective against sap-sucking insect pests. Screening results were based on $LC_{50}$ values against cotton aphid (Aphis gossypii), one of the dangerous pests of various crop plants including cotton. Among the isolates, the Bt#BREF24 showed promising results, and upon purification the aphidicidal protein was recognized as a binary toxin. One of the components of this binary toxin was identified by peptide sequencing to be a homolog of Vip2A that has been reported previously in other Bacillus spp. Vip2 belongs to the binary toxin group Vip1-Vip2, and is responsible for the enzymatic activity; and Vip1 is the translocation and receptor binding protein. The two genes encoding the corresponding proteins of the binary toxin, designated as vip2Ae and vip1Ae, were cloned from the Bt#BREF24, sequenced, and heterologously expressed in Escherichia coli. Aphid feeding assay with the recombinant proteins confirmed that these proteins are indeed the two components of the binary toxins, and the presence of both partners is essential for the activity. Aphid specificity of the binary toxin was further verified by ligand blotting experiment, which identified an ~50 kDa receptor in the brush border membrane vesicles of the cotton aphids only, but not in the lepidopteran insects. Our finding holds a promise of its use in future as a candidate gene for developing transgenic crop plants tolerant against sap-sucking insect pests.

Rheinheimera aquatica sp. nov., Antimicrobial Activity-Producing Bacterium Isolated from Freshwater Culture Pond

  • Chen, Wen-Ming;Lin, Chang-Yi;Young, Chiu-Chung;Sheu, Shih-Yi
    • Journal of Microbiology and Biotechnology
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    • v.20 no.10
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    • pp.1386-1392
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    • 2010
  • A bacterial strain designated GR5$^T$, previously isolated from a freshwater culture pond in Taiwan while screening for bacteria for antimicrobial compounds, was characterized using a polyphasic taxonomic approach. Strain GR5$^T$ was found to be Gram-negative, aerobic, greenish-yellow colored, rod-shaped, and motile by means of a single polar flagellum. Growth occurred at $10-40^{\circ}C$ (optimum, $35^{\circ}C$), pH 7.0-8.0 (optimum pH 8.0), and with 0-2.0% NaCl (optimum, 0.5-1.0%). The major fatty acids were $C_{16:1}{\omega}7c$(36.3%), $C_{16:0}$(16.6%), $C_{12:0}$ 3-OH (12.5%), and $C_{18:1}{\omega}7c$(9.1%). The major respiratory quinone was Q-8, and the DNA G+C content of the genomic DNA was 51.9 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain GR5$^T$ belongs to the genus Rheinheimera, where its most closely related neighbors are Rheinheimera texasensis A62-14B$^T$ and Rheinheimera tangshanensis JA3-B52$^T$ with sequence similarities of 98.1% and 97.5%, respectively, and the sequence similarities to any other recognized species within Gammaproteobacteria are less than 96.5%. The mean level of DNA-DNA relatedness between strain GR5$^T$ and R. texasensis A62-14B$^T$, the strain most closely related to the isolate, was $26.5{\pm}7.6%$. Therefore, based on the phylogenetic and phenotypic data, strain GR5$^T$ should be classified as a novel species, for which the name Rheinheimera aquatica sp. nov. is proposed. The type strain is GR5$^T$ (=BCRC 80081$^T$=LMG 25379$^T$).

Systemic and Cell-Type Specific Profiling of Molecular Changes in Parkinson's Disease

  • Lee, Yunjong
    • Interdisciplinary Bio Central
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    • v.4 no.3
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    • pp.6.1-6.12
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    • 2012
  • Parkinson's disease (PD) is a complicated neurodegenerative disorder although it is oftentimes defined by clinical motor symptoms originated from age dependent and progressive loss of dopaminergic neurons in the midbrain. The pathogenesis of PD involves dopaminergic and nondopaminergic neurons in many brain regions and the molecular mechanisms underlying the death of different cell types still remain to be elucidated. There are indications that PD causing disease processes occur in a global scale ranging from DNA to RNA, and proteins. Several PD-associated genes have been reported to play diverse roles in controlling cellular functions in different levels, such as chromatin structure, transcription, processing of mRNA, translational modulation, and posttranslational modification of proteins. The advent of quantitative high throughput screening (HTS) tools makes it possible to monitor systemic changes in DNA, RNA and proteins in PD models. Combined with dopamine neuron isolation or derivation of dopamine neurons from PD patient specific induced pluripotent stem cells (PD iPSCs), HTS techonologies will provide opportunities to draw PD causing sequences of molecular events in pathologically relevant PD samples. Here I discuss previous studies that identified molecular functions in which PD genes are involved, especially those signaling pathways that can be efficiently studied using HTS methodologies. Brief descriptions of quantitative and systemic tools looking at DNA, RNA and proteins will be followed. Finally, I will emphasize the use and potential benefits of PD iPSCs-derived dopaminergic neurons to screen signaling pathways that are initiated by PD linked gene mutations and thus causative for dopaminergic neurodegneration in PD.

Screening of Domestic Silkworm Strains for Efficient Heterologous Protein Expression by Bombyx mori Nuclear Polyhedrosis Virus (BmNPV)

  • Jo, Sun Jung;Choi, Ji-Hyun;Kang, Ju-Il;Lim, Jae-Hwan;Seok, Young Sik;Lee, Jae Man;Kusakabe, Takahiro;Hong, Sun Mee
    • International Journal of Industrial Entomology and Biomaterials
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    • v.29 no.2
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    • pp.185-192
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    • 2014
  • Recombinant proteins can be generated quickly and easily in large amounts and at low-cost in silkworm larvae by using Bombyx mori nuclear polyhedrosis virus (BmNPV). We searched for high-permissive silkworm strains that have high production levels of heterologous proteins and are thus suitable for use as biofactories. In this study, we performed the analysis using a BmNPV vector expressing luciferase as a marker, and we confirmed protein expression by evaluating luciferase activity, determined by western blotting and luciferase ELISA, and confirmed transcription expression by semi- and quantitative real time PCR. For the selection of host silkworm strains, we first chose 52 domestic BmNPV sensitive strains and then identified 10 high-permissive and 5 low-permissive strains. In addition, to determine which hybrid of the high-permissive strains would show heterosis, nine strains derived through three-way crossing were tested for luciferase activity by western blotting, and luciferase ELISA. We found a correlation between luciferase activity and luciferase protein expression, but not transcription. There was no noticeable difference in protein expression levels between Jam313 as the high-permissive control strain and the three-way hybrid strains; however, the three-way cross strains showed lower luciferase activity compared with Jam313. In this study, luciferase protein production in the larvae of 52 domestic silkworm strains was elucidated using BmNPV.

The Medical Information Protection and major Issues (의료정보 유출의 문제점과 의료정보보호)

  • Jeun, Young-Ju
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.12
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    • pp.251-258
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    • 2012
  • The protection of medical information by major Issues on medical information to protect the individuals' privacy on medical information. Especially, Issues of medical service information, medical record, insurance, employment, Genetic technology including genetic test and screening, gene therapy and genetic enhancement is developing rapidly. Defensibility of medical information documentation is tested in the courts. medical information can be illicitly accessed from anywhere and transmitted across the quickly and with risk of detection. Once data is distributed on the internet, it may become available to anyone who wishes to purchase it, and it cannot be expunge. Patient privacy protection of medical information is controlled mostly by patient consent laws that define how and when a patient must consent before a physician may disclose the patient's medical information to anyone else. enterprise that offers consumers commodities or services is checking problem about customer information of management system is checking problem about customer information of management system essentially. Therefore, in this paper will find a way out to Protection of medical information by major Issues on medical information.

In Silico Screening for Angiogenesis-Related Genes in Rat Astrocytes

  • Kim, Soo-Young;Lee, Sae-Won;You, Sung Yong;Rha, Sun Young;Kim, Kyu-Won
    • Genomics & Informatics
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    • v.2 no.1
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    • pp.36-44
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    • 2004
  • Astrocytes play supportive roles for neurons in the brain. Recently, they have been accepted to have various functions in the vascular system as well as in the nervous system. We investigated the differential gene expression in rat astrocytes according to the oxygen tension, which is a crucial factor for angiogenesis. A cDNA microarray was performed to find the genes whose expression was sensitive to oxygen tension. We found 26 genes in the astrocyte were found and classified into 4 groups. In order to show the genes' relevancy to angiogenesis, seven of the 26 genes were investigated to see whether they have capabilities of interaction with angiogenesis­related factors in AngioDB. Through this investigation, we found interactions of three proteins with angiogenesis-related factors. These genes were further investigated with a new focus on the vascular endothelial growth factor (VEGF) expression in an astrocyte based on our hypothesis that astrocytes can have effects on endothelial angiogenesis via the release of VEGF. Collectively, we identified several genes whose expressions were dependent on the oxygen concentration of the astrocyte. Furthermore, the relevancy of astrocytes to angiogenesis was investigated using preexisting information of AngioDB, and suggested a possible signaling pathway for VEGF expression in the aspects of brain endothelial angiogenesis by astrocytes.

Screening of Gamma Radiation-Induced Pathogen Resistance Rice Lines against Xanthomonas oryzae pv. oryzae (방사선을 이용한 벼 흰잎마름병 저항성 돌연변이 벼 계통의 선발)

  • Lim, Chan Ju;Lee, Ha Yeon;Kim, Woong Bom;Ahmad, Raza;Moon, Jae Sun;Kim, Dong Sub;Kwon, Suk-Yoon
    • Journal of Radiation Industry
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    • v.4 no.3
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    • pp.209-213
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    • 2010
  • Bacterial blight is one of the most serious diseases of rice (Oryza sativa L.), and it has been known that Xanthomonas oryzae pv. oryzae (Xoo) causes this disease symptom. To develop resistance rice cultivars against Xoo, 3,000 lines of $M_3$ mutants, which were irradiated with gamma ray, were tested by 'scissor-dip method' primarily, and 191 putative resistant lines were selected. In $M_4$ generation, these lines were screened again with various ways such as measuring of symptom of bacterial blight in leaf, number of tiller, fresh weight, and phenotypic segregation ratio in next generation. Finally, six resistance lines were selected. RT-PCR analysis revealed that these lines displayed high level of R-genes such as Xa21, Pi36, and Pi-ta. These results indicate that mutations by gamma ray cause disruptions of regulatory signal transduction systems of these R-genes. Furthermore, these selected mutants could be useful for the development of rice cultivar resistant to Xoo.

Ginsenoside Rh2 upregulates long noncoding RNA STXBP5-AS1 to sponge microRNA-4425 in suppressing breast cancer cell proliferation

  • Park, Jae Eun;Kim, Hyeon Woo;Yun, Sung Hwan;Kim, Sun Jung
    • Journal of Ginseng Research
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    • v.45 no.6
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    • pp.754-762
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    • 2021
  • Background: Ginsenoside Rh2, a major saponin derivative in ginseng extract, is recognized for its anti-cancer activities. Compared to coding genes, studies on long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) that are regulated by Rh2 in cancer cells, especially on competitive endogenous RNA (ceRNA) are sparse. Methods: LncRNAs whose promoter DNA methylation level was significantly altered by Rh2 were screened from methylation array data. The effect of STXBP5-AS1, miR-4425, and RNF217 on the proliferation and apoptosis of MCF-7 breast cancer cells was monitored in the presence of Rh2 after deregulating the corresponding gene. The ceRNA relationship between STXBP5-AS1 and miR-4425 was examined by measuring the luciferase activity of a recombinant luciferase/STXBP5-AS1 plasmid construct in the presence of mimic miR-4425. Results: Inhibition of STXBP5-AS1 decreased apoptosis but stimulated growth of the MCF-7 cells, suggesting tumor-suppressive activity of the lncRNA. MiR-4425 was identified to have a binding site on STXBP5-AS1 and proven to be downregulated by STXBP5-AS1 as well as by Rh2. In contrast to STXBP5-AS1, miR-4425 showed pro-proliferation activity by inducing a decrease in apoptosis but increased growth of the MCF-7 cells. MiR-4425 decreased luciferase activity from the luciferase/STXBP5-AS1 construct by 26%. Screening the target genes of miR-4425 and Rh2 revealed that Rh2, STXBP5-AS1, and miR-4425 consistently regulated tumor suppressor RNF217 at both the RNA and protein level. Conclusion: LncRNA STXBP5-AS1 is upregulated by Rh2 via promoter hypomethylation and acts as a ceRNA, sponging the oncogenic miR-4425. Therefore, Rh2 controls the STXBP5-AS1/miR-4425/RNF217 axis to suppress breast cancer cell growth.

Antifungal Mechanism of Action of Lauryl Betaine Against Skin-Associated Fungus Malassezia restricta

  • Do, Eunsoo;Lee, Hyun Gee;Park, Minji;Cho, Yong-Joon;Kim, Dong Hyeun;Park, Se-Ho;Eun, Daekyung;Park, Taehun;An, Susun;Jung, Won Hee
    • Mycobiology
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    • v.47 no.2
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    • pp.242-249
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    • 2019
  • Betaine derivatives are considered major ingredients of shampoos and are commonly used as antistatic and viscosity-increasing agents. Several studies have also suggested that betaine derivatives can be used as antimicrobial agents. However, the antifungal activity and mechanism of action of betaine derivatives have not yet been fully understood. In this study, we investigated the antifungal activity of six betaine derivatives against Malassezia restricta, which is the most frequently isolated fungus from the human skin and is implicated in the development of dandruff. We found that, among the six betaine derivatives, lauryl betaine showed the most potent antifungal activity. The mechanism of action of lauryl betaine was studied mainly using another phylogenetically close model fungal organism, Cryptococcus neoformans, because of a lack of available genetic manipulation and functional genomics tools for M. restricta. Our genome-wide reverse genetic screening method using the C. neoformans gene deletion mutant library showed that the mutants with mutations in genes for cell membrane synthesis and integrity, particularly ergosterol synthesis, are highly sensitive to lauryl betaine. Furthermore, transcriptome changes in both C. neoformans and M. restricta cells grown in the presence of lauryl betaine were analyzed and the results indicated that the compound mainly affected cell membrane synthesis, particularly ergosterol synthesis. Overall, our data demonstrated that lauryl betaine influences ergosterol synthesis in C. neoformans and that the compound exerts a similar mechanism of action on M. restricta.