• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.466-473
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• 2013

Gene expression is regulated by a wide range of mechanisms at the DNA sequence level. In addition, gene expression is also regulated by epigenetic mechanisms through DNA methylation, histone modification, and ncRNA. To understand the regulation of gene expression at the epigenetic level, we constructed aging related gene database and analyzed epigenetic properties that are focused on DNA methylation. The DNA methylation of promoter or upstream region of the genes induces to repress the gene expression. We compared and analyzed distribution between whole human genes and aging related genes in the epigenetic properties such as CGI distribution, methylation motif pattern, and TFBS (transcription factor binding site) distribution. In contrast to methylation motif pattern, CGI and TFBS distributions are positively correlated with epigenetic regulation of aging related gene expression. In this study, the epigenetic data about DNA methylation of the aging genes will provide us to understand phenomena of the aging and epigenetic mechanism for regulation of aging related genes.

• BMB Reports
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• v.28 no.6
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• pp.494-498
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• 1995

Maize mitochondrial tRNAs for isoleucine have been isolated using a putative $tRNA^{Ile}$ gene probe which has been previously isolated and characterized. It contains the 5'-CAT anticodon which would normally recognize the AUG methionine codon. The nucleotide sequence of one of these tRNAs has been partially determined, and contains a modified nucleotide at the first position of the anticodon. This type of posttranscriptional modification event could change the specificity of amino acid acceptance of a tRNA, unlike that deduced from the corresponding gene. An aminoacylation experiment also demonstrated that these purified tRNAs have isoleucine acceptance activity but no methionine-accepting activity.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.225-243
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• 2016

Thanks to recent advance of next generation sequencing techniques, RNA-seq enabled to have an unprecedented opportunity to identify transcript variants with isoform diversity and allelic imbalance (Anders et al., 2012) by different transcriptional rates. To date, it is well known that those features might be associated with the aberrant patterns of disease complexity such as tissue (Anders and Huber, 2010; Anders et al., 2012; Nariai et al., 2014) specific differential expression at isoform levels or tissue specific allelic imbalance in mal-functionality of disease processes, etc. Nevertheless, the knowledge of post-transcriptional modification and AI in transcriptomic and genomic areas has been little known in the traditional platforms due to the limitation of technology and insufficient resolution. We here stress the potential of isoform variability and allelic specific expression that are relevant to the abnormality of disease mechanisms in transcriptional genetic regulatory networks. In addition, we systematically review how robust Bayesian approaches in RNA-seq have been developed and utilized in this regard in the field.

• Microbiology and Biotechnology Letters
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• v.23 no.4
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• pp.384-389
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• 1995

Streptoalloteichus hindustanus ATCC 31219, a nebramycin complex producer, is similar to Streptomyeces tenebrarius in a viewpoint of resistance to a wide range of aminoglycoside antibiotics. S. tenebrarius has resistance mechanisms of 16s rRNA methylation and aminogycoside modification. However, it is not known whether resistance mechanisms of Stall. hindustanus are the same as in S. tenebrarius. Therefore, we have tried to isolate resistance determinants from Stall. hindustanus. Two different types of aminoglycoside resistance determinants were isolated from Stall. hindustanus and expressed in Streptomyces lividans TK24. The apramycin resistance gene (amr) and the tobramycin resistance gene (tmr) isolated from Stall. hindustanus showed broad resistance spectrum against a dozen of aminoglycoside antibiotics. The complete nucleotide sequences of apramycin resistance gene (amr) were determined. The deduced amino acid sequence of the amr gene of Stall hindustanus ATCC 31219 showed extensive sequence homology to the 16s rRNA methylase gene (kamB) of S. tenebrarius.

• BMB Reports
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• v.49 no.3
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• pp.135-136
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• 2016

Small interfering RNAs (siRNAs) have been developed to intentionally repress a specific gene expression by directing RNA-induced silencing complex (RISC), mimicking the endogenous gene silencer, microRNAs (miRNAs). Although siRNA is designed to be perfectly complementary to an intended target mRNA, it also suppresses hundreds of off-targets by the way that miRNAs recognize targets. Until now, there is no efficient way to avoid such off-target repression, although the mode of miRNA-like interaction has been proposed. Rationally based on the model called "transitional nucleation" which pre-requires base-pairs from position 2 to the pivot (position 6) with targets, we developed a simple chemical modification which completely eliminates miRNA-like off-target repression (0%), achieved by substituting a nucleotide in pivot with abasic spacers (dSpacer or C3 spacer), which potentially destabilize the transitional nucleation. Furthermore, by alleviating steric hindrance in the complex with Argonaute (Ago), abasic pivot substitution also preserves near-perfect on-target activity (∼80-100%). Abasic pivot substitution offers a general means of harnessing target specificity of siRNAs to experimental and clinical applications where misleading and deleterious phenotypes from off-target repression must be considered.

• Preventive Nutrition and Food Science
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• v.5 no.4
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• pp.184-188
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• 2000

HMG-CoA reductase is th rate-limiting enzyme of cholesterol biosynthesis. As intracellular levels of cholesterol should be regulated elaborately in response to external stimuli an internal needs, the expression of the HMG-CoA reductase gene is regulated intricately at several different levels from transcription to post-translational modification. In this study, we investigated the regulatory mechanism of HMG-CoA reductase gene expression at the post-transcriptional/pre-translational levels in a baby hamster kidney cell line, C100. when 25-hydroxycholesterol was added to cells cultured in medium containing 5% delipidized fetal bovine serum and 25$\mu$M lovastatin, the levels of HMG-CoA reductase mRNA decreased rapidly, which seemed to be due to the increased degradation of reductase mRNA. These suppressive effects of 25-hydroxycholesterol on MG-CoA reductase mRNA levels were blocked by a translation inhibitor, cycloheximide. Similarly, actinomycin D and 5,6-dichloro-1-$\beta$-D-ribofuranosylbenzimidazole, transcription inhibitors, blocked the 25-hydroxycholesterol-mediated degradation of HMG-CoA reductase mRNA. These results indicate that new protein/RNA synthesis is required for the degradation of HMG-CoA reductase mRNA. In addition, data from the transfection experiments shows that cis-acting determinants, regulating the stability of reductase mRNA, were scattered in the sequence corresponding to 1766-4313 based on the sequence of Syrian hamster HMG-CoA reductase cDNA. Our data suggests that sterol-mediated destabilization of reductase mRNA might be one of the important regulatory mechanism of HMG-CoA reductase gene expression.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1684-1690
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• 2005

Using mRNA differential display technique, we investigated differential gene expression in hybrids relative to their parents in a diallel cross involving four chicken breeds in order to provide an insight into the molecular basis of heterosis in chicken. The results indicated that there was extensive differential gene expression between chicken F1 hybrids and their parents which was classified into four kinds of patterns as following: (1) bands only detected in hybrid F1; (2) bands only absent in hybrid F1; (3) bands only detected in parent P1 or P2; (4) bands absent in parent P1 or P2. Forty-two differentially expressed cDNAs were cloned and sequenced, and their expression patterns were confirmed by Reverse-Northern dot blot. Sequence analysis and database searches revealed that genes showed differential expression between hybrid and parents were regulatory and functional genes involved in metabolism, mRNA splicing, transcriptional regulation, cell cycles and protein modification. These results indicated that hybridization between two parents can cause changes in expression of a variety of genes. In conclusion, that the altered pattern of gene expression in hybrids may be responsible for heterosis in chickens.

• Animal Bioscience
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• v.36 no.4
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• pp.555-569
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• 2023

Objective: The objective of this study was to investigate the effects of N⁶-Methyladenosine modification-circRNA-zinc finger protein 638 (m⁶A-circRNA-ZNF638) on the induced activation of secondary hair follicle (SHF) stem cells with its potential mechanisms in cashmere goats. Methods: The m⁶A modification of ZNF638 was analyzed using methylation immunoprecipitation with real-time quantitative polymerase chain reaction technique in SHF stem cells. The effects of circRNA-ZNF638 on the induced activation of SHF stem cells in m⁶A dependence were evaluated through the overexpression of circRNA-ZNF638/its m⁶A-deficient mutants in circRNA-ZNF638 knockdown SHF stem cells. The competitive binding of miR-361-5p to circRNA-ZNF638/Wnt5a 3'- untranslated region was analyzed through Dual-luciferase reporter assay. Results: The m⁶A-circRNA-ZNF638 had significantly higher transcription at anagen SHF bulge of cashmere goats compared with that at telogen, as well as it positively regulated the induced activation of SHF-stem cells in cashmere goats. Mechanismly, m⁶A-circRNA-ZNF638 sponged miR-361-5p to heighten the transcriptional expression of Wnt5a gene in SHF-stem cells. We further demonstrated that the internal m⁶A modification within circRNA-ZNF638 is required for mediating the miR-361-5p/Wnt5a pathway to regulate the induced activation of SHF stem cells through an introducing of m⁶A-deficient mutant of circRNA-ZNF638. Conclusion: The circRNA-ZNF638 contributes the proper induced activation of SHF-stem cells in cashmere goats in m⁶A-dependent manner through miR-361-5p/Wnt5a axis.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.351-355
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• 2005

In the storage roots of sweetpotato (Ipomoea batatas (L.) Lam. cv. Kokei 14), 10 to 20% of starch is essentially unbranched linear amylose and the other major component is branched amylopectin. Amylose is produced by the enzyme GBSSI (granule bound starch synthase I), whereas amylopectin is produced by a concerted action of soluble starch synthase and starch branching enzymes (SBEI and SBEII). We constructed double-stranded RNA (dsRNA) interference vectors of GBSSI and IbSBEII and introduced them into sweetpotato genome via Agrobacterium-mediated gene transformation. The endogenous GBSSI expression was inhibited by dsRNA of GBSSI in 73 % of transgenic plants giving rise to the storage tubers containing amylopectin but not amylose. On the other hand, all sweetpotato plants transformed with dsRNA of IbSBEII contained a larger amount of amylose than the non-transgenic control (up to 25% compared to 10% in the controls). The RNA interference (RNAi) is effectively inhibited the gene expression in thestarch metabolic pathway and modified the characteristics of starch in sweetpotato.

• International Journal of Stem Cells
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• v.16 no.2
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• pp.135-144
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• 2023

Background and Objectives: Melanocyte (MC), derived from neural crest stem cell (NCSC), are involved in the production of melanin. The mechanism by which NCSC differentiates to MC remains unclear. N6-methyladenosine (m6A) modification was applied to discuss the potential mechanism. Methods and Results: NCSCs were isolated from hair follicles of rats, and were obtained for differentiation. Cell viability, tyrosinase secretion and activity, and transcription factors were combined to evaluated the MC differentiation. RT-qPCR was applied to determine mRNA levels, and western blot were used for protein expression detection. Total m6A level was measured using methylated RNA immunoprecipitation (MeRIP) assay, and RNA immunoprecipitation was used to access the protein binding relationship. In current work, NCSCs were successfully differentiated into MCs. Fat mass and obesity associated gene (FTO) was aberrant downregulated in MCs, and elevated FTO suppressed the differentiation progress of NCSCs into MCs. Furthermore, microphthalmia-associated transcription factor (Mitf), a key gene involved in MC synthesis, was enriched by FTO in a m6A modification manner and degraded by FTO. Meanwhile, the suppression functions of FTO in the differentiation of NCSCs into MCs were reversed by elevated Mitf. Conclusions: In short, FTO suppressed the differentiating ability of hair follicle-derived NCSCs into MCs by m6A modifying Mitf.