• Title/Summary/Keyword: Expression Strategies

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Effect of Galactose Feeding Strategy on Heterologous Human Lipocortin-I Production in the Fed-Batch Culture of Saccharomyces cerevisiae Controlled by the GAL10 Promoter

  • Chung, Bong-Hyun;Kim, Byung-Moon;Rhee, Sang-Ki;Park, Young-Hoon;Nam, Soo-Wan
    • Journal of Microbiology and Biotechnology
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    • v.5 no.4
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    • pp.224-228
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    • 1995
  • Fed-batch fermentations were conducted to produce human lipocortin-I (LC1), a potential anti-inflammatory agent, from recombinant Sacchromyces cerevisiae carrying a galactose-inducible expression system. The cell growth, expression level of LC1, and the plasmid stability were investigated under various LC1 induction modes performed by three different galactose feeding strategies. Galactoe was fed to induce the expression of LCl from the beginning (initial induction) of culture or when the cell concentration reached 120 OD (mid-phase induction) or 300 OD (late induction). Among the three galactose-induction modes tested, the initial induction mode yielded the best result with respect to a final expression level of LC1. Fedbatch fermentation with initial induction mode produced LC1 at a conentration of 220 mg/l, which corresponded to 1.38- and 1.53-fold increases over those produced by mid-phase and late induction modes.

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Stimulation of Oligonucleotide-Directed Gene Correction by Redβ Expression and MSH2 Depletion in Human HT1080 Cells

  • Xu, Ke;Stewart, A. Francis;Porter, Andrew C.G.
    • Molecules and Cells
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    • v.38 no.1
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    • pp.33-39
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    • 2015
  • The correction of disease-causing mutations by single-strand oligonucleotide-templated DNA repair (ssOR) is an attractive approach to gene therapy, but major improvements in ssOR efficiency and consistency are needed. The mechanism of ssOR is poorly understood but may involve annealing of oligonucleotides to transiently exposed single-stranded regions in the target duplex. In bacteria and yeast it has been shown that ssOR is promoted by expression of $Red{\beta}$, a single-strand DNA annealing protein from bacteriophage lambda. Here we show that $Red{\beta}$ expression is well tolerated in a human cell line where it consistently promotes ssOR. By use of short interfering RNA, we also show that ssOR is stimulated by the transient depletion of the endogenous DNA mismatch repair protein MSH2. Furthermore, we find that the effects of $Red{\beta}$ expression and MSH2 depletion on ssOR can be combined with a degree of cooperativity. These results suggest that oligonucleotide annealing and mismatch recognition are distinct but interdependent events in ssOR that can be usefully modulated in gene correction strategies.

Odorant G protein-coupled receptors as potential therapeutic targets for adult diffuse gliomas: a systematic analysis and review

  • Cho, Hee Jin;Koo, JaeHyung
    • BMB Reports
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    • v.54 no.12
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    • pp.601-607
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    • 2021
  • Odorant receptors (ORs) account for about 60% of all human G protein-coupled receptors (GPCRs). OR expression outside of the nose has functions distinct from odor perception, and may contribute to the pathogenesis of disorders including brain diseases and cancers. Glioma is the most common adult malignant brain tumor and requires novel therapeutic strategies to improve clinical outcomes. Here, we outlined the expression of brain ORs and investigated OR expression levels in glioma. Although most ORs were not ubiquitously expressed in gliomas, a subset of ORs displayed glioma subtype-specific expression. Moreover, through systematic survival analysis on OR genes, OR51E1 (mouse Olfr558) was identified as a potential biomarker of unfavorable overall survival, and OR2C1 (mouse Olfr15) was identified as a potential biomarker of favorable overall survival in isocitrate dehydrogenase (IDH) wild-type glioma. In addition to transcriptomic analysis, mutational profiles revealed that somatic mutations in OR genes were detected in > 60% of glioma samples. OR5D18 (mouse Olfr1155) was the most frequently mutated OR gene, and OR5AR1 (mouse Olfr1019) showed IDH wild-type-specific mutation. Based on this systematic analysis and review of the genomic and transcriptomic profiles of ORs in glioma, we suggest that ORs are potential biomarkers and therapeutic targets for glioma.

The Effects of Mothers' Emotional Expression and Self-compassion on Preschoolers' Emotion Regulation: The Mediating Role of Preschoolers' Self-compassion (어머니의 정서표현 및 자기자비가 유아의 정서조절능력에 미치는 영향: 유아 자기자비의 매개효과)

  • Mina Kwon;Jinsuk Lee
    • Korean Journal of Childcare and Education
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    • v.20 no.3
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    • pp.67-83
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    • 2024
  • Objective: This study aimed to determine whether preschoolers' self-compassion mediates the effects of mothers' emotional expression and self-compassion on preschoolers' emotional regulation abilities in children aged 4 to 6 years. Methods: The study included 305 mothers residing in City J who were raising preschoolers aged 4 to 6. Data collected were analyzed for the significance of the mediating effects among the main variables using the GLM Mediation Model in the JAMM package of the Jamovi 2.3.16 statistical program. Results: Firstly, statistically significant positive and negative correlations were found among the main variables. Secondly, preschoolers' positive self-compassion was found to partially mediate the relationship between mothers' positive emotional expression and preschoolers' emotional regulation abilities. Furthermore, preschoolers' negative self-compassion partially mediated the relationship between mothers' negative emotional expressions and preschoolers' emotional regulation abilities. Conclusion/Implications: This study identified parental and child variables influencing preschoolers' emotional regulation abilities and discussed intervention strategies for education and counseling to enhance these abilities.

Development of Upcycling Fashion Design Using Surrealistic Expression Techniques (초현실주의 표현기법을 활용한 업사이클링 패션디자인 개발)

  • Yi Fan Fu;Cha Hyun Kim
    • Journal of the Korea Fashion and Costume Design Association
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    • v.26 no.3
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    • pp.51-64
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    • 2024
  • As concerns over environmental issues grow, the fashion industry is looking for sustainable and eco-friendly directions. In particular, the fashion industry is actively introducing upcycling to address environmental pollution. In addition, the fashion trend of surrealistic expression techniques are drawing attention, reflecting modern people's desire to relieve stress and escape from daily life. Accordingly, this study focused on modern environmental issues and the pursuit of personality away from popularization, and proposed upcycling using surrealist expression techniques. As a research method, literature research and prior research were conducted through data collection, and the concepts of surrealism, upcycling, and fashion expression techniques were summarized. Based on this survey, the theme of "Dream Forest" was decided upon, and design development and the production of real works were carried out using CLO 3D. This study is expected to contribute to presenting sustainable strategies and directions in the field of fashion design, spreading social awareness of sustainable fashion, while aiming to provide new insights to fashion designers, and enhancing the social awareness of sustainable fashion.

Antimicrobial Activity of Bacteriophage Endolysin Produced in Nicotiana benthamiana Plants

  • Kovalskaya, Natalia;Foster-Frey, Juli;Donovan, David M.;Bauchan, Gary;Hammond, Rosemarie W.
    • Journal of Microbiology and Biotechnology
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    • v.26 no.1
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    • pp.160-170
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    • 2016
  • The increasing spread of antibiotic-resistant pathogens has raised the interest in alternative antimicrobial treatments. In our study, the functionally active gram-negative bacterium bacteriophage CP933 endolysin was produced in Nicotiana benthamiana plants by a combination of transient expression and vacuole targeting strategies, and its antimicrobial activity was investigated. Expression of the cp933 gene in E. coli led to growth inhibition and lysis of the host cells or production of trace amounts of CP933. Cytoplasmic expression of the cp933 gene in plants using Potato virus X-based transient expression vectors (pP2C2S and pGR107) resulted in death of the apical portion of experimental plants. To protect plants against the toxic effects of the CP933 protein, the cp933 coding region was fused at its Nterminus to an N-terminal signal peptide from the potato proteinase inhibitor I to direct CP933 to the delta-type vacuoles. Plants producing the CP933 fusion protein did not exhibit the severe toxic effects seen with the unfused protein and the level of expression was 0.16 mg/g of plant tissue. Antimicrobial assays revealed that, in contrast to gram-negative bacterium E. coli (BL21(DE3)), the gram-positive plant pathogenic bacterium Clavibacter michiganensis was more susceptible to the plant-produced CP933, showing 18% growth inhibition. The results of our experiments demonstrate that the combination of transient expression and protein targeting to the delta vacuoles is a promising approach to produce functionally active proteins that exhibit toxicity when expressed in plant cells.

Improved Homologous Expression of the Acidic Lipase from Aspergillus niger

  • Zhu, Si-Yuan;Xu, Yan;Yu, Xiao-Wei
    • Journal of Microbiology and Biotechnology
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    • v.30 no.2
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    • pp.196-205
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    • 2020
  • In this study, the acidic lipase from Aspergillus niger (ANL) was homologously expressed in A. niger. The expression of ANL was significantly improved by the expression of the native ANL with the introns, the addition of the Kozak sequence and the optimization of the signal sequences. When the cDNA sequence of ANL fused with the glaA signal was expressed under the gpdA promoter in A. niger, no lipase activity could be detected. We then tried to improve the expression by using the full-length ANL gene containing three introns, and the lipase activity in the supernatant reached 75.80 U/ml, probably as a result of a more stable mRNA structure. The expression was further improved to 100.60 U/ml by introducing a Kozak sequence around the start codon due to a higher translation efficiency. Finally, the effects of three signal sequences including the cbhI signal, the ANL signal and the glaA signal on the lipase expression were evaluated. The transformant with the cbhI signal showed the highest lipase activity (314.67 U/ml), which was 1.90-fold and 3.13-fold higher than those with the ANL signal and the glaA signal, respectively. The acidic lipase was characterized and its highest activity was detected at pH 3.0 and a temperature of 45℃. These results provided promising strategies for the production of the acidic lipase from A. niger.

De novo assembly, annotation and gene expression profiles of gonads of Cytorace-3, a hybrid lineage of Drosophila nasuta nasuta and D. n. albomicans

  • Ponnanna, Koushik;DSouza, Stafny M.;Ramachandra, Nallur B.
    • Genomics & Informatics
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    • v.19 no.1
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    • pp.8.1-8.12
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    • 2021
  • Cytorace-3 is a laboratory evolved hybrid lineage of Drosophila nasuta nasuta males and Drosophila nasuta albomicans females currently passing ~850 generations. To assess interracial hybridization effects on gene expression in Cytorace-3 we profiled the transcriptomes of mature ovaries and testes by employing Illumina sequencing technology and de novo transcriptome assembling strategies. We found 26% of the ovarian, and 14% of testis genes to be differentially expressed in Cytorace-3 relative to the expressed genes in the parental gonadal transcriptomes. About 5% of genes exhibited additive gene expression pattern in the ovary and 3% in the testis, while the remaining genes were misexpressed in Cytorace-3. Nearly 772 of these misexpressed genes in the ovary and 413 in the testis were either over-or under-dominant. Genes following D. n. nasuta dominance was twice (270 genes) than D. n. albomicans dominance (133 genes) in the ovary. In contrast, only 105 genes showed D. n. nasuta dominance and 207 showed D. n. albomicans dominance in testis transcriptome. Of the six expression inheritance patterns, conserved inheritance pattern was predominant for both ovary (73%) and testis (85%) in Cytorace-3. This study is the first to provide an overview of the expression divergence and inheritance patterns of the transcriptomes in an independently evolving distinct hybrid lineage of Drosophila. This recorded expression divergence in Cytorace-3 surpasses that between parental lineages illustrating the strong impact of hybridization driving rapid gene expression changes.

The Effect of Growth Condition on a Soluble Expression of Anti-EGFRvIII Single-chain Antibody in Escherichia coli NiCo21(DE3)

  • Dewi, Kartika Sari;Utami, Ratna Annisa;Hariyatun, Hariyatun;Pratiwi, Riyona Desvy;Agustiyanti, Dian Fitria;Fuad, Asrul Muhamad
    • Microbiology and Biotechnology Letters
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    • v.49 no.2
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    • pp.148-156
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    • 2021
  • Single-chain antibodies against epidermal growth factor receptor variant III (EGFRvIII) are potentially promising agents for developing antibody-based cancer treatment strategies. We described in our previous study the successful expression of an anti-EGFRvIII scFv antibody in Escherichia coli. However, we could also observe the formation of insoluble aggregates in the periplasmic space, limiting the production yield of the active product. In the present study, we investigated the mechanisms by which growth conditions could affect the expression of the soluble anti-EGFRvIII scFv antibody in small-scale E. coli NiCo21(DE3) cultures, attempting to maximize production. The secreted scFv molecules were purified using Ni-NTA magnetic beads and protein characterization was performed using SDS-PAGE and western blot analyses. We used the ImageJ software for protein quantification and determined the antigen-binding activity of the scFv antibody against the EGFRvIII protein. Our results showed that the highest percentage of soluble scFv expression could be achieved under culture conditions that combined low IPTG concentration (0.1 mM), low growth temperature (18℃), and large culture dish surface area. We found moderate-yield soluble scFv production in the culture medium after lactose-mediated induction, which was also beneficial for downstream protein processing. These findings were confirmed by conducting western blot analysis, indicating that the soluble, approximately 30-kDa scFv molecule was localized in the periplasm and the extracellular space. Moreover, the antigen-binding assay confirmed the scFv affinity against the EGFRvIII antigen. In conclusion, our study reveals that low-speed protein expression is preferable to obtain more soluble anti-EGFRvIII scFv protein in an E. coli expression system.

Transcriptional profiles of rock bream iridovirus (RBIV) using microarray approaches

  • Myung-Hwa, Jung;Jun-Young, Song;Sung-Ju, Jung
    • Journal of fish pathology
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    • v.35 no.2
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    • pp.141-155
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    • 2022
  • Rock bream iridovirus (RBIV) causes high mortality and economic losses in the rock bream (Oplegnathus fasciatus) aquaculture industry in Korea. Viral open reading frames (ORFs) expression profiling at different RBIV infection stages was investigated using microarray approaches. Rock bream were exposed to the virus and held for 7 days at 23 ℃ before the water temperature was reduced to 17 ℃. Herein, 28% mortality was observed from 24 to 35 days post infection (dpi), after which no mortality was observed until 70 dpi (end of the experiment). A total of 27 ORFs were significantly up- or down-regulated after RBIV infection. In RBIV-infected rock bream, four viral genes were expressed after 2 dpi. Most RBIV ORFs (26 genes, 96.2%) were significantly elevated between 7 and 20 dpi. Among them, 12 ORF (44.4%) transcripts reached their peak expression intensity at 15 dpi, and 14 ORFs (51.8%) were at peak expression intensity at 20 dpi. Expression levels began to decrease after 25 dpi, and 92.6% of ORFs (25 genes) were expressed below 1-fold at 70 dpi. From the microarray data, in addition to the viral infection, viral gene expression profiles were categorized into three infection stages, namely, early (2 dpi), middle (7 to 20 dpi), and recovery (25 and 70 dpi). RBIV ORFs 009R, 023R, 032L, 049L, and 056L were remarkably expressed during RBIV infection. Furthermore, six ORFs (001L, 013R, 052L, 053L, 058L, and 061L) were significantly expressed only at 20 dpi. To verify the cDNA microarray data, we performed quantitative real-time PCR, and the results were similar to that of the microarray. Our results provide novel observations on broader RBIV gene expression at different stages of infection and the development of control strategies against RBIV infection.