• Proceedings of the Botanical Society of Korea Conference
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• 1996.07a
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• pp.26-38
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• 1996

To investigate the regulation of plant histone H2A gene expression, we isolated two H2A genes (TH254 and TH274) from wheat, which encode different types of variants. Both genes had an intron in the coding region. In the promoters, some characteristics sequences, such as Oct and Nona motifs, which are conserved among plant histone genes were also found, and they were located in a short region (about 120 bp) upstream from the putative TATA box. Analyses of promoter activity with H2A-GUS fusion genes in the transient system using tobacco protoplasts revealed novel types of positive cis-acting sequences in the TH254 promoter: a direct repeat of a 13-bp sequence (AGTTACATTATTG) and a stretch composed of an AT-rich sequence (ATATAGAAAATTAAAA) and a G-box (CACGTG). A quantitative S1 assay of the mRNA amounts from the TH254/GUS and TH274/GUG chimeric genes in stably transformed and cell cycle-synchronized tobacco cell lines showed that the promoters of both genes contained at least one cis-acting element responsible for S phase-specific expression. Histochemical analysis of transgenic tobacco plants carrying the chimeric genes showed that the promoters of the two H2A genes were both active in developing seedlings and flower organs but regulated in different manner.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1241-1245
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• 2015

The aim of the present work was to examine the putative promoter region of the operon ansPAB and to determine the general elements required for the regulation of transcriptional activity. The transcriptional start site of the ansPAB promoter was determined by using highresolution S1-nuclease mapping. Sequence analysis of this region showed -10 and -35 elements, which were consistent with consensus sequences for R. etli promoters that are recognized by the major form of RNA polymerase containing the σ⁷⁰ transcription factor. Mutation studies affecting several regions located upstream of the transcriptional start site confirmed the importance of these elements on transcriptional expression.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1919-1926
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• 2020

CRISPR interference (CRISPRi) has been developed as a transcriptional control tool by inactivating the DNA cleavage ability of Cas9 nucleases to produce dCas9 (deactivated Cas9), and leaving dCas9 the ability to specifically bind to the target DNA sequence. CRISPR/Cas9 technology has limitations in designing target-specific single-guide RNA (sgRNA) due to the dependence of protospacer adjacent motif (PAM) (5'-NGG) for binding target DNAs. Reportedly, Cas9-NG recognizing 5'-NG as the PAM sequence has been constructed by removing the dependence on the last base G of PAM through protein engineering of Cas9. In this study, a dCas9-NG protein was engineered by introducing two active site mutations in Cas9-NG, and its ability to regulate transcription was evaluated in the gal promoter in E. coli. Analysis of cell growth rate, D-galactose consumption rate, and gal transcripts confirmed that dCas9-NG can completely repress the promoter by recognizing DNA targets with PAM of 5'-NGG, NGA, NGC, NGT, and NAG. Our study showed possible PAM sequences for dCas9-NG and provided information on target-specific sgRNA design for regulation of both gene expression and cellular metabolism.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.80.1-80
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• 2003

Several plant and microbial genes that could confer disease resistance in transgenic rice plants are being cloned and characterized. We are currently constructing transgenic rice lines that overexpress the gene products, such as a galactinol synthase, a defensin, and a bacterial ACC deaminase. Subtractive hybridization of a rice cDNA library constructed from the Xanthomonas oryzae-infected ice leaves resulted in isolation of many inducible cDNA clones including a elongation factor EF2, a oryzain alpha, a catalase, a aldehyde dehydrogenase, a S-adenosylmethionine synthetase, a caffeic acid O-methyltransferase, a glyceraldehyde-3-phosphate dehydrogenase, a light-regulated protein, nKY transcription factors, and a nucleotide diphosphate kinase. Some genes among those may be useful genetic sources for construction of disease resistant transgenic rice. Full lengths of the rice OsFIERG and a rice oryzain genomic clones were cloned, and serial deletion fragments of the promoter regions of these genes were fused with GUS reporter gene in pCAMBIA1201, respectively. Promoter activities of these constructs will be examined upon various stresses and Pathogen infections to obtain the pathogen specific inducible-promoter. This work was supported by a grant from BioGreen 21 Program, Rural Development Administration, Republic of Korea.

• The Journal of Internal Korean Medicine
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• v.29 no.1
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• pp.32-41
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• 2008

Background : Monocyte chemoattractant protein-1(MCP-1), one of the CC chemokines, appears to play a significant role in asthma pathogenesis. It was reported that polymorphism in the MCP-1(-2518 A/G promoter) was associated with asthma in Caucasians, but the association of this polymorphism and asthma patients in the Korean population has not yet been clarified. Objective : We investigated the possible association between 2 polymorphisms (-2518 A/G promoter and Cys35Cys) and asthma patients in a Korean population. Materials and Methods : DNA samples were obtained from 86 Korean asthma patients and 270 healthy controls. MCP-1 genomic variants (-2518 A/G promoter and Cys35Cys polymorphism) were detected by PCR-RFLP. Level of MCP-1 was measured by ELISA for each genotype (n=8) (AA, AG, GG) and allele types of -2518 A/G promoter polymorphism for control subjects. Results : The Cys35Cys polymorphism was associated with asthma patients in Korean population [genotype distribution ($X^{2}=16.011$, P<0.001)]. Comparison of the two groups revealed no detectable differences in genotype and allele frequencies of the -2518 A/G polymorphism. Haplotype frequencies analysis revealed significant difference $(X^{2}=51.70$, P<0.001). MCP-1 serum level of subjects with G genotype of -2518 A/G promoter polymorphism was statistically higher than that with AA genotype (P<0.05). Conclusion : Our data indicate that no association exists between the MCP-1 -2518 A/G polymorphism and asthma susceptibility in the Korean population. However, it is noteworthy that the high prevalence of the -2518 G allele in the Korean population suggests a potentially important ethnic variation in the regulation of MCP-1 production. This variation must be considered in gene-association studies in different ethnic populations.

• Molecules and Cells
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• v.44 no.3
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• pp.146-159
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• 2021

DNA methylation, and consequent down-regulation, of tumour suppressor genes occurs in response to epigenetic stimuli during cancer development. Similarly, human oncoviruses, including human papillomavirus (HPV), up-regulate and augment DNA methyltransferase (DNMT) and histone deacetylase (HDAC) activities, thereby decreasing tumour suppressor genes (TSGs) expression. Ubiquitin-like containing PHD and RING finger domain 1 (UHRF1), an epigenetic regulator of DNA methylation, is overexpressed in HPV-induced cervical cancers. Here, we investigated the role of UHRF1 in cervical cancer by knocking down its expression in HeLa cells using lentiviral-encoded short hairpin (sh)RNA and performing cDNA microarrays. We detected significantly elevated expression of thioredoxin-interacting protein (TXNIP), a known TSG, in UHRF1-knockdown cells, and this gene is hypermethylated in cervical cancer tissue and cell lines, as indicated by whole-genome methylation analysis. Up-regulation of UHRF1 and decreased TXNIP were further detected in cervical cancer by western blot and immunohistochemistry and confirmed by Oncomine database analysis. Using chromatin immunoprecipitation, we identified the inverted CCAAT domain-containing UHRF1-binding site in the TXNIP promoter and demonstrated UHRF1 knockdown decreases UHRF1 promoter binding and enhances TXNIP expression through demethylation of this region. TXNIP promoter CpG methylation was further confirmed in cervical cancer tissue by pyrosequencing and methylation-specific polymerase chain reaction. Critically, down-regulation of UHRF1 by siRNA or UHRF1 antagonist (thymoquinone) induces cell cycle arrest and apoptosis, and ubiquitin-specific protease 7 (USP7), which stabilises and promotes UHRF1 function, is increased by HPV viral protein E6/E7 overexpression. These results indicate HPV might induce carcinogenesis through UHRF1-mediated TXNIP promoter methylation, thus suggesting a possible link between CpG methylation and cervical cancer.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.1
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• pp.13-25
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• 2009

Purpose: The DNA repair protein, $O^6$-methylguanine-DNA methyltransferase (MGMT), removes alkyl adducts from the $O^6$ position of guanine. Epigenetic inactivation of MGMT has been found in human neoplasia and considered one of the implicated factors in chemoresistance. Materials and Methods: Sixty-two patiensts with soft tissue sarcomas (STS) were analyzed for the status of MGMT protein expression by immunohistochemistry and the promoter hypermethylation of the MGMT gene using methylation-specific PCR. Result: The loss of MGMT expression was found in 20 cases (32.3%) of total 62 STS. MGMT promoter hypermethylation rate was 25.0% (11/44 cases). The loss of MGMT expression showed significant association with high AJCC stage, high FNCLCC grade, and aggressive behavior. However,when the group who received chemotherapy was analyzed (n=27), loss of MGMT expression was correlated with worse survival in multivariate analysis (p=0.024). MGMT promoter hypermethylation is associated with high FNCLCC grade. MGMT promoter hypermethylation status had a strong correlation with loss of MGMT expression (p=0.000). Conclusion: Our results suggest that MGMT promoter hypermethylation and loss of MGMT expression had a tendency to be associated with poor prognosis and that loss of MGMT protein expression is frequently occurs via MGMT promoter hypermethylation.

• Journal of Microbiology
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• v.37 no.2
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• pp.102-110
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• 1999

Genetic determinant for the secondary metabolism was studied in heterologous expression in Streptomyces lividans TK-24 using Streptomyces griseus ATCC 10137 as a donor strain. Chromosomal DNA of S. griseus was ligated into the high-copy number Streptomyces shuttle plasmid, pWHM3, and introduced into S. lividans TK-24. A plasmid clone with 4.3-kb BamHI DNA of S. griseus (pMJJ201) was isolated by detecting for stimulatory effect on actinorhodin production by visual inspection. The 4.3-kb BamHI DNA was cloned into pWHM3 under the control of the strong constitutive ermEp promoter in both directions (pMJJ202); ermEp promoter-mediated transcription for coding sequence reading right to left: pMJJ203; ermEp promoter-mediated transcription for coding sequence reading left to right) and reintroduced into S. lividans TK-24. The production of actinorhodin was markedly stimulated due to introduction of pMJJ202 on regeneration agar. The introduction of pMJJ202 also stimulated production of actinorhodin and undecylproidigiosin in submerged culture employing the actinorhodin production medium. Introduction of pMJJ203 resulted in a marked decrease of production of the two pigments. Nucleotide sequence analysis of the 4.3-kb region revealed three coding sequences: two coding sequences reading left to right, ORF1 and ORF2, one coding sequence reading right to left, ORF3. Therefore, it was suggested that the ORF3 product was responsible for the stimulation of antibiotic production. The C-terminal region of ORF3 product showed a local alignment with Myb-related transcriptional factors, which implicated that the ORF3 product might be a novel DNA-binding protein related to the regulation of secondary metabolism in Streptomyces.

• Molecules and Cells
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• v.26 no.2
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• pp.212-215
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• 2008

The GC-rich discriminator sequence between the -10 region and the transcription start site of the rnpB promoter is responsible for stringent control of M1 RNA synthesis. The rnpB promoter also contains a G nucleotide at the previously identified transcription start site. In this study, we examined by mutagenesis of G to A whether this +1G nucleotide is involved in the stringent response. We found that the change did not alter the stringent response. Since the +1 mutation might alter transcription initiation, we compared the transcription start sites of the wt and mutant promoters by primer extension analysis. Surprisingly, we found that wild type rnpB transcription starts at both the +1G position (70%) and the -1C position (30%), and that the +1A mutation led to transcription initiation exclusively at the -1C position. We also generated two transversion mutations at the -1 position, both of which led to transcription starting exclusively at that position. The -1G mutant promoter gave a stringent signal similar to the wild-type, whereas the -1A mutant generated a significantly less stringent signal. Base on these results, we propose that a short sequence, up to 7 bp downstream of the -10 region, is involved in the stringent response of the rnpB promoter.

• Molecules and Cells
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• v.26 no.5
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• pp.459-461
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• 2008

Much research evidence supports the hypothesis that chronic, low-grade inflammation related to innate immunity may play an important role in the pathophysiology of type 2 diabetes mellitus (T2DM). Runt-related transcription factor 2 (RUNX2; MIM# 600211) acts as a scaffold that controls the integration, organization, and assembly of nucleic acids. To examine whether the novel promoter variant in RUNX2 is associated with the risk of T2DM and related phenotypes, RUNX2-742G > T was genotyped in 378 T2DM patients and 382 normal controls recruited in the Korean T2DM Study. Statistical analysis revealed that RUNX2-742G > T was associated with serum triglyceride level (TG) in nondiabetic controls, although it was not associated with the risk of T2DM. Individuals who carry T/T, T/G, and G/G genotypes had the highest ($2.061{\pm}0.20$), intermediate ($2.01{\pm}0.19$), and the lowest ($1.97{\pm}0.18$) levels of log [TG (mmol/l)] (P = 0.007), respectively. Our data on this important variant of RUNX2 suggest that lipid metabolism might be affected by genetic polymorphisms in the promoter region.