• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.254-254
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• 2022

Astragalus membranaceus (A. membranaceus) has traditionally been used as a medicinal plant in East Asia for the treatment ofvarious diseases. A. membranaceus belongs to the legume family and is known to be rich in substances such as flavonoids and saponins. Recent pharmacological studies of A. membranaceus have shown that the plant has immunomodulatory, anti-oxidant, anti-cancer, and anti-inflammatory effects. However, knowledge of major biosynthetic pathways in A. membranaceu is still lacking. Recently developed sequencing techniques enable high-quality transcriptome analysis in plants, which is recognized as an important part in elucidating the regulatory mechanisms of many plant secondary metabolic pathways. However, it is difficult to predict the number of transcripts because plant transcripts contain a large number of isoforms due to alternative splicing events, which can vary depending on the assembly platform used. In this study, we constructed three unigene sets using Pac-Bio isoform sequencing, Trinity and rnaSPAdes assembly for detailed transcriptome analysis mA. membranaceus. Furthermore, all genes involved in the flavonoid biosynthetic pathway were searched from three unigene sets, and structural comparisons and expression profiles between these genes were analyzed. The isoflavone synthesis was active in most tissues. Flavonol synthesis was mainly active in leaves and flowers, and anthocyanin synthesis was specific in flowers. Gene structural analysis revealed structural differences in the flavonoid-related genes derived from the three unigene sets. This study suggests the need for the application of multiple unigene sets for the analysis of key biosynthetic pathways in plants.

• Molecules and Cells
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• v.41 no.4
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• pp.342-350
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• 2018

Flowering time is determined by florigens. These genes include, Heading date 3a (Hd3a) and Rice FT 1 (RFT1) in rice, which are specifically expressed in the vascular tissues of leaves at the floral transition stage. To study the cis-regulatory elements present in the promoter region of Hd3a, we generated transgenic plants carrying the 1.75-kb promoter fragment of Hd3a that was fused to the ${\beta}$-glucuronidase (GUS) reporter gene. Plants expressing this construct conferred a vascular cell-specific expression pattern for the reporter gene. However, GUS was expressed in leaves at all developmental stages, including the early seedling stage when Hd3a was not detected. Furthermore, the reporter was expressed in roots at all stages. This suggests that the 1.75-kb region lackings cis-elements that regulate leaf-specific expression at the appropriate developmental stages. Deletion analyses of the promoter region indicated that regulatory elements determining vascular cell-specific expression are present in the 200-bp region between -245 bp and -45 bp from the transcription initiation site. By transforming the Hd3a-GUS construct to rice cultivar 'Taichung 65' which is defective in Ehd1, we observed that Ehd1 is the major regulatory element that controls Hd3a promoter activity.

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.104-108
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• 2010

We describe the construction of derivatives of wild type and mutant lrp genes that encode 6XHis-tag Lrps. These derivatives of wild type and mutant Lrp could be useful for in vitro studies including Lrp conformational changes. We show that 6XHis-tag Lrp wild type and 6XHis-tag Lrp R145W bind with similar patterns in vitro to 21 bp duplex DNA containing the consensus sequences of Lrp sites of upstream of the ilvIH operon. In addition, we report here the 6XHis-tag Lrp R145W is useful to investigate the conformational changes of Lrp in solution by using its own intrinsic fluorescence characteristics.

• The Plant Pathology Journal
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• v.28 no.3
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• pp.259-269
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• 2012

Protein phosphatase 2A (PP2A), a family of serine/threonine protein phosphatases, plays an important role in balancing the phosphorylation status of cellular proteins for regulating diverse biological functions in eukaryotic organisms. Despite intensive studies in mammals, limited information on its role is available in filamentous fungi. Here, we investigated the functional roles of genes for a putative B' delta regulatory subunit (FgPP2AR) and a catalytic subunit (FgPP2AC) of PP2A in a filamentous ascomycete, Fusarium graminearum. Molecular characterization of an insertional mutant of this plant pathogenic fungus allowed us to identify the roles of FgPP2AR. Targeted gene replacement and complementation analyses demonstrated that the deletion of FgPP2AR, which was constitutively expressed in all growth stages, caused drastic changes in hyphal growth, conidia morphology/germination, gene expression for mycotoxin production, sexual development and pathogenicity. In particular, overproduction of aberrant cylindrical-shaped conidia is suggestive of arthroconidial induction in the ${\Delta}FgPP2AR$ strain, which has never been described in F. graminearum. In contrast, the ${\Delta}FgPP2AC$ strain was not significantly different from its wild-type progenitor in conidiation, trichothecene gene expression, and pathogenicity; however, it showed reduced hyphal growth and no perithecial formation. The double-deletion ${\Delta}FgPP2AR;{\Delta}FgPP2AC$ strain had more severe defects than single-deletion strains in all examined phenotypes. Taken together, our results indicate that both the putative regulatory and catalytic subunits of PP2A are involved in various cellular processes for fungal development in F. graminearum.

• Korean Journal of Veterinary Service
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• v.44 no.4
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• pp.195-207
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• 2021

Species A rotaviruses (RVAs) replicate and assemble their immature particles within electron dense compartments known as viroplasms, where lipid droplets (LDs) interact with the viroplasm and facilitate viral replication. Despite the importance of LD formation in the life cycle of RVAs, the upstream molecules modulating LD formation remain unclear. This study aimed to find out the role of sterol regulatory element-binding proteins (SREBPs) in reprogramming of LD formation after RVA infection. Here, we demonstrate that RVA infection reprograms the sterol regulatory element-binding proteins (SREBPs)-dependent lipogenic pathways in virus-infected cells, and that both SREBP-1 and -2 transactivated genes, which are involved in fatty acid and cholesterol biosynthesis, are essential for LD formation. Our results showed that pharmacological inhibition of SREBPs using AM580 and betulin and inhibition of their downstream cholesterol biosynthesis (simvastatin for HMG-CoA reductase) and fatty acid enzymes (TOFA) negatively modulated the intracellular triacylglycerides and cholesterol levels and their resulting LD and viroplasm formations. Interestingly, pharmacological inhibition of SREBPs significantly reduced RVA protein synthesis, genome replication and progeny production. This study identified SREBPs-mediated lipogenic reprogramming in RVA-infected host cells, which facilitates virus replication through LD formation and its interaction with viroplasms, suggesting that SREBPs can be a potential target for the development of efficient and affordable therapeutics against RVA infection.

• BMB Reports
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• v.40 no.2
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• pp.156-162
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• 2007

Two lysis-defective but DNA synthesis non-defective temperature-sensitive (ts) mutants of mycobacteriophage L1, L1G23ts23 and L1G25ts889 were found to be defective also in phage-specific RNA synthesis in the late period of their growth at 42$^{\circ}C$each to the extent of 50% of that at 32$^{\circ}C$The double mutant, L1G23ts23G25ts889 showed the ts defect in phage RNA synthesis that was nearly additive of those shown individually by the two single-mutant parents. Both G23 and G25 were shown to start functioning sometimes between 30 and 45 min after infection but the former gene might be dispensable after 45 min, while the latter was not. Northern analysis also shows that at 42$^{\circ}C$>, L1G23ts23 affects RNA synthesis more strongly than L1G25ts889 from L1 DNA segments that serve as the template for late gene transcription. Among the 21 virion and 12 non-virion late proteins synthesized by L1, L1G23ts23 is defective in the synthesis of at least 9 virion and all of non-virion proteins at 42$^{\circ}C$>. In contrast, L1G25ts889 is completely defective in synthesis of all the 33 late proteins. Possible roles of G23 and G25 in the positive regulation of transcription of different sets of late genes of L1 have been discussed.

• BMB Reports
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• v.38 no.2
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• pp.151-160
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• 2005

By a cDNA array representing 2308 signal transduction related genes, we studied the expression profiles of HeLa cells stably transfected by Hepatitis C virus nonstructural protein 4B (HCV-NS4B). The alterations of the expression of four genes were confirmed by real-time quantitative RT-PCR; and the aldo-keto reductase family 1, member C1 (AKR1C1) enzyme activity was detected in HCV-NS4B transiently transfected HeLa cells and Huh-7, a human hepatoma cell line. Of the 2,308 genes we examined, 34 were up-regulated and 56 were down-regulated. These 90 genes involved oncogenes, tumor suppressors, cell receptors, complements, adhesions, transcription and translation, cytoskeletion and cellular stress. The expression profiling suggested that multiple regulatory pathways were affected by HCV-NS4B directly or indirectly. And since these genes are related to carcinogenesis, host defense system and cell homeostatic mechanism, we can conclude that HCV-NS4B could play some important roles in the pathogenesis mechanism of HCV.

• Biomedical Science Letters
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• v.18 no.2
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• pp.165-168
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• 2012

Hox proteins containing DNA-binding homedomain act as transcription factors important for anteroposterior body patterning during vertebrate embryogenesis. However, the precise mechanisms by which signal pathways are transduced to regulate the Hox gene expression are not clear. In the course of an attempt to isolate an upstream regulatory factor(s) controlling Hox genes, protein kinase B alpha (Akt1) has been identified as a putative regulator of Hox genes through in silico analysis (GEO profile). In the Gene Expression Omnibus (GEO) dataset GDS1784 at the NCBI (National Center for Biotechnology Information) site, Hox genes were differentially expressed depending on the presence or absence of Akt1. Since it was not well known how Akt1 regulates the specific Hox genes, whose transcription was reported to be regulated by epigenetic modifications such as histone acetylation, methylation etc., the expression of Gcn5, a histone acetyltransferase (HAT), was analyzed in wild type (WT) as well as in $Akt1^{-/-}$ mouse embryonic fibroblast (MEF) cells. RT-PCR analysis revealed that the amount of Gcn5 mRNA was similar in both WT and $Akt1^{-/-}$ MEFs. However, the protein level of Gcn5 was significantly increased in $Akt1^{-/-}$ MEF cells. The half life of Gcn5 was 1 hour in wild type whereas 8 hours in $Akt1^{-/-}$ MEF. These data all together, indicate that Gcn5 is post-transcriptionally down-regulated and the protein stability is negatively regulated by Akt1 in MEF cells.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6375-6378
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• 2012

Background: Small-cell lung cancer (also known as SCLC) is an aggressive form and untreated patients generally die within about 3 months. To obtain further insight into mechanism underlying malignancy with this cancer, an miRNA synergistic regulatory network was constructed and analyzed in the present study. Method: A miRNA microarray dataset was downloaded from the NCBI GEO database (GSE27435). A total of 546 miRNAs were identified to be expressed in SCLC cells. Then a miRNA synergistic network was constructed, and the included miRNAs mapped to the network. Topology analysis was also performed to analyze the properties of the synergistic network. Consequently, we could identified constitutive modules. Further, common target genes of each module were identified with CFinder. Finally, enrichment analysis was performed for target genes. Results: In this study, a miRNA synergistic network with 464 miRNAs and 2981 edges was constructed. According to the topology analysis, the topological properties between the networks constructed by LC related miRNAs and LC unrelated miRNAs were significantly different. Moreover, a module cilque0 could be identified in our network using CFinder. The module included three miRNAs (hsa-let-7c, hsa-let-7b and hsa-let-7d). In addition, several genes were found which were predicted to be common targets of cilque0. The enrichment analysis demonstrated that these target genes were enriched in MAPK signaling pathways. Conclusions: Although limitations exist in the current data, the results uncovered here are important for understanding the key roles of miRNAs in SCLC. However, further validation is required since our results were based on microarray data derived from a small sample size.

• Molecules and Cells
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• v.25 no.3
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• pp.358-367
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• 2008

The embryonic germ cell (EGCs) of mice is a kind of pluripotent stem cell that can be generated from pre- and post-migratory primordial germ cells (PGCs). Most previous studies on DNA methylation of EGCs were restricted to 12.5 days post coitum (dpc). This study was designed to establish and characterize murine EGC lines from migrated PGCs as late as 13.5 dpc and to estimate the degrees of methylation of their imprinted genes as well as of the non-imprinted locus, Oct4, using an accurate and quantitative method of measurement. We established five independent EGC lines from post migratory PGCs of 11.5-13.5 dpc from C57BL/6 ${\times}$ DBA/2 F1 hybrid mouse fetuses. All the EGCs exhibited the typical features of pluripotent cells including hypomethylation of the Oct4 regulatory region. We examined the methylation status of three imprinted genes; Igf2, Igf2r and H19 in the five EGC lines using bisulfite genomic sequencing analysis. Igf2r was almost unmethylated in all the EGC lines irrespective of the their sex and stage of isolation; Igf2 and H19 were more methylated than Igf2r, especially in male EGCs. Moreover, EGCs derived at 13.5 dpc exhibited higher levels of DNA methylation than those from earlier stages. These results suggest that in vitro derived EGCs acquire different epigenotypes from their parental in vivo migratory PGCs, and that sex-specific de novo methylation occurs in the Igf2 and H19 genes of EGCs.