• Journal of Microbiology and Biotechnology
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• v.32 no.7
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• pp.911-917
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• 2022

As valuable antibiotics, microbial natural products have been in use for decades in various fields. Among them are polyene compounds including nystatin, amphotericin, and nystatin-like Pseudonocardia polyenes (NPPs). Polyene macrolides are known to possess various biological effects, such as antifungal and antiviral activities. NPP A1, which is produced by Pseudonocardia autotrophica, contains a unique disaccharide moiety in the tetraene macrolide backbone. NPP B1, with a heptane structure and improved antifungal activity, was then developed via genetic manipulation of the NPP A1 biosynthetic gene cluster (BGC). Here, we generated a Streptomyces artificial chromosomal DNA library to isolate a large-sized NPP B1 BGC. The NPP B1 BGC was successfully isolated from P. autotrophica chromosome through the construction and screening of a bacterial artificial chromosome (BAC) library, even though the isolated 140-kb BAC clone (named pNPPB1s) lacked approximately 8 kb of the right-end portion of the NPP B1 BGC. The additional introduction of the pNPPB1s as well as co-expression of the 32-kb portion including the missing 8 kb led to a 7.3-fold increase in the production level of NPP B1 in P. autotrophica. The qRT-PCR confirmed that the transcription level of NPP B1 BGC was significantly increased in the P. autotrophica strain containing two copies of the NPP B1 BGCs. Interestingly, the NPP B1 exhibited a previously unidentified SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) inhibition activity in vitro. These results suggest that the Streptomyces BAC cloning of a large-sized, natural product BGC is a valuable approach for titer improvement and biological activity screening of natural products in actinomycetes.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.15 no.3
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• pp.101-109
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• 2015

Classic galactosemia (OMIM #230400) is an autosomal recessive inherited metaboic disorder caused by a deficiency of the galactose-1-phosphate uridyltransferase (GALT, EC2.7.7.12) due to mutations in the GALT gene. If untreated, classic galactosemia is a potentially lethal disease presenting with poor feeding, vomiting, jaundice, liver failure, increased bleeding tendency, and septicemia leading to death within a few days after birth. Since 2006, expansion of newborn screening has been enabled the early diagnosis and early intervention of classic galactosemia in Korea. However, newborn screening, followup testing for confirmatory diagnosis and intervention for galactosemia continue to present challenges. In Korea, the prevalence of the classic galactosemia is considered relatively low compared to that of western countries. And the genotype is also clearly different from those of other population. Therefore, our own guideline for confirmatory diagnosis and intervention is needed. Here, the diagnostic algorithm for galactosemia after positive newborn screening result in Korea has been proposed. Considering the low prevalence and different mutation spectrum in Koreans, the early mutation analysis of GALT gene could be a useful tool for the accurate diagnosis and making any treatment decision.

• Molecules and Cells
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• v.27 no.5
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• pp.577-582
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• 2009

The development of a high-throughput functional genomic screening provides a novel and expeditious approach in identifying critical genes involved in specific biological processes. Here we describe a cell-based cDNA screening system to identify the transcription activators of BiP, an endoplasmic reticulum (ER) chaperone protein. BiP promoter contains the ER stress element which is commonly present in the genes involved in unfolded protein response (UPR) that regulates protein secretion in cells. Therefore, the positive regulators of BiP may also be utilized to improve the recombinant protein production through modulation of UPR. Four BiP activators, including human UDP-glucose:glycoprotein glucosyltransferase 1 (HUGT1), are identified by the cDNA screening. Overexpression of HUGT1 leads to a significant increase in the production of recombinant erythropoietin, interferon ${\gamma}$, and monoclonal antibody in HEK293 cells. Our results demonstrate that the cDNA screening for BiP activators may be effective to identify the novel BiP regulators and HUGT1 may serve as an ideal target gene for improving the recombinant protein production in mammalian cells.

• Korean Journal of Environmental Agriculture
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• v.20 no.2
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• pp.74-78
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• 2001

Two Bacterial strains 1-C and 51-C capable of utilizing aniline as a sole source of carbon and energy were isolated from river waters. Both strains were identified as Pseudomonas rhodesiae based on their physiological and biochemical characteristics and 16S rRNA gene sequence. The strains were able to grow on the mineral salt media containing aniline at concentrations up to 6,000 ${\mu}g/mL$. Pseudomonas rhodesiae 51-C completely degraded aniline in a mineral salt medium containing 300 ${\mu}g/mL$ of aniline as a sole carbon and energy source within 16 hours. The optimum pH and temperature for its growth and aniline degradation were 7.0 and $30^{\circ}C{\sim}35^{\circ}C$, respectively. This is the first report of aniline degradation by P. rhodesiae strains.

• Journal of Microbiology and Biotechnology
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• v.33 no.3
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• pp.329-338
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• 2023

Enterohemorrhagic Escherichia coli (EHEC) is a foodborne pathogen that produces attaching and effacing lesions on the large intestine and causes hemorrhagic colitis. It is primarily transmitted through the consumption of contaminated meat or fresh produce. Similar to other bacterial pathogens, antibiotic resistance is of concern for EHEC. Furthermore, since the production of Shiga toxin by this pathogen is enhanced after antibiotic treatment, alternative agents that control EHEC are necessary. This study aimed to discover alternative treatments that target virulence factors and reduce EHEC toxicity. The locus of enterocyte effacement (LEE) is essential for EHEC attachment to host cells and virulence, and most of the LEE genes are positively regulated by the transcriptional regulator, Ler. GrlA protein, a transcriptional activator of ler, is thus a potential target for virulence inhibitors of EHEC. To identify the GrlA inhibitors, an in vivo high-throughput screening (HTS) system consisting of a GrlA-expressing plasmid and a reporter plasmid was constructed. Since the reporter luminescence gene was fused to the ler promoter, the bioluminescence would decrease if inhibitors affected the GrlA. By screening 8,201 compounds from the Korea Chemical Bank, we identified a novel GrlA inhibitor named Grlactin [3-[(2,4-dichlorophenoxy)methyl]-4-(3-methylbut-2-en-1-yl)-4,5-dihydro-1,2,4-oxadiazol-5-one], which suppresses the expression of LEE genes. Grlactin significantly diminished the adhesion of EHEC strain EDL933 to human epithelial cells without inhibiting bacterial growth. These findings suggest that the developed screening system was effective at identifying GrlA inhibitors, and Grlactin has potential for use as a novel anti-adhesion agent for EHEC while reducing the incidence of resistance.

• The Plant Pathology Journal
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• v.26 no.1
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• pp.70-79
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• 2010

Rice blast is one of the serious devastating diseases. This study was carried out to determine the genetic diversities of blast resistance (R) genes form 86 accessions of aromatic rice with eight SNP markers, z4792, zt4792, z60510, zt6057, k6415, k6411, k39575 and t256, which showed the close-set linkage to 6 major genes, Piz, Piz-t, Pik, Pik-m, Pik-p, and Pit. Four accessions of indica type, Mayataung, Yekywin Yinkya Hmwe, Basmati9-93, and Basmati5854, showed the positive amplicons of six major genes. Among 86 accessions, 83 accessions were detected both or one of Piz and Piz-t genes. Seventy three accessions contained the Piz gene with z4792 marker. In addition, 30 and 71 accessions possessed Piz-t gene with zt4792 and zt6057 markers, respectively. Ten accessions showed the positive bands for the Piz-t gene with both zt4792 and zt6057 markers. Only one accession, Khau Nua Keo, was not amplified for both Piz and Piz-t gene. But japonica type, Gerdeh, possessed only Piz gene between Piz and Piz-t. Fifty two accessions showed the three of Pik multiple genes and Pit gene. Four accessions, Iari7447, Daebunhyangdo2, Shiyayuuine, and Basmati 6129 possessed a Pik-p gene. Especially, Pit gene on chromosome 1 was detected with t256 marker in all of 83 accessions, exception of A-2, one accession of japonica type.

• BMB Reports
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• v.43 no.12
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• pp.789-794
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• 2010

A novel gene, designated mgt-6, containing four splicing variants, was isolated from a gene trap clone library of C3H/10T1/2 cells transfected with retroviral promoterless gene-trap vector, ROSAFARY. The transcript variants were differentially expressed in murine tissues and cell lines and differentially responded to diverse stimuli including TGF-${\beta}1$ and mitogen-activated protein kinase (MAPK) inhibitors. The mgt-6 gene encoded a protein of 37 or 11 amino acid residuals with cytoplasmic distribution. However, when C3H/10T1/2 cells were treated with 5-azacytidine, the protein translocated into cell nucleus as indicated by fused LacZ or C-terminally tagged EGFP. Our preliminary results suggest that further study on the role of mgt-6 gene in cell transformation and differentiation may be of significance.

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.797-805
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• 1999

T sergenti cDNA library were constructed to get a more broad information about the structural, functional or antigenic properties of the proteins, and analyzes for their partial cDNA sequences and expression sequences tags(ESTg). The mRNA were purified from T sergenti isolates to identify the information of antigen gene, then first and second strand cDNA was synthesized. EcoR I adaptor ligation and Xho I enzyme restriction were used to the synthesized cDNA, and ligated into a Uni-ZAP XR vector. T sergenti cDNA library was constructed with packaging and amplification in vitro. Antibody screening was performed with constructed T sergenti cDNA library using antisera against T sergenti. Among those clones, eight phagemids were rescued from the recombinant in vivo excision with f1 helper phage. Using the analysis of endonuclease restriction and PCR, the recombinant cDNA were proved having a 0.5-3.0kb of inserts. The eight of partial cDNA clones' sequences were obtained and examined for their homology using BLASTN and BLASTX. The eight of sequenced clones were classified into three groups according to the basis of database searches. A total 3,045bp of partial cDNA sequence were determined from six clones. The putatively identified clones contain a cytochrome c gene, a heat shock protein gene, a cyclophilin gene, and a ribosomal protein gene. The unidentified clones have a homology to ATP-binding protein(mtrA) gene of S argillaceus, DNA-binding protein(DBP) gene of Pseudorabies virus 85kDa merozoite protein gene of B bovis, mRNA spm1 protein of T annulata and glycine-rich RNA-binding protein mRNA of O sativa etc.

• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.517-522
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• 1998

The cry1 gene content of a collection of Bacillus thuringiensis strains, which include new isolates from Malaysia and Indonesia, was determined by a multiplex PCR using a set of eight oligonucleotide forward primers specific to cry1Aa, cry1Ab, cry1Ac, cry1Ba, cry1Ca, cry1Da, cry1Ea, and cry1Fa genes, and two reverse primers, one specific to cry1Ab and the other common to the remaining cry1 genes. Two-thirds of the 59 strains screened were cry1 positive and contained one to four different genes. The cry gene profiles correlated well with toxicities of the strains to lepidopteran insects. The method can be used for rapid screening of a large number of new isolates as the total DNA extracted by boiling cells from single colonies can be used directly in the PCR. However, it is not suitable for follow-up monitoring of specific commercial strains after application in the field as the PCR product profiles of these strains could not be differentiated from those of new isolates.

• Molecules and Cells
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• v.27 no.6
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• pp.697-701
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• 2009

We previously identified cancer-upregulated gene 2 (CUG2) as a commonly up-regulated gene in various human cancer tissues, especially in ovary, liver, and lung (Lee et al., 2007a). CUG2 was determined to be a nuclear protein that exhibited high proto-oncogenic activities when overexpressed in NIH3T3 mouse fibroblast cells. To identify other cellular functions of CUG2, we performed yeast two-hybrid screening and identified CENP-T, a component of CENP-A nucleosome complex in the centromere, as an interacting partner of CUG2. Moreover, CENP-A, the principle centromeric determinant, was also found in complex with CENP-T/CUG2. Immunofluorescent staining revealed the co-localization of CUG2 with human centromeric markers. Inhibition of CUG2 expression drastically affected cell viability by inducing aberrant cell division. We propose that CUG2 is a new component of the human centromeric complex that is required for proper chromosome segregation during mitosis.