• Molecules and Cells
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• v.44 no.10
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• pp.746-757
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• 2021

Plant somatic cells can be reprogrammed into a pluripotent cell mass, called callus, which can be subsequently used for de novo shoot regeneration through a two-step in vitro tissue culture method. MET1-dependent CG methylation has been implicated in plant regeneration in Arabidopsis, because the met1-3 mutant exhibits increased shoot regeneration compared with the wild-type. To understand the role of MET1 in de novo shoot regeneration, we compared the genome-wide DNA methylomes and transcriptomes of wildtype and met1-3 callus and leaf. The CG methylation patterns were largely unchanged during leaf-to-callus transition, suggesting that the altered regeneration phenotype of met1-3 was caused by the constitutively hypomethylated genes, independent of the tissue type. In particular, MET1-dependent CG methylation was observed at the blue light receptor genes, CRYPTOCHROME 1 (CRY1) and CRY2, which reduced their expression. Coexpression network analysis revealed that the CRY1 gene was closely linked to cytokinin signaling genes. Consistently, functional enrichment analysis of differentially expressed genes in met1-3 showed that gene ontology terms related to light and hormone signaling were overrepresented. Overall, our findings indicate that MET1-dependent repression of light and cytokinin signaling influences plant regeneration capacity and shoot identity establishment.

• Journal of Microbiology and Biotechnology
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• v.20 no.9
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• pp.1314-1321
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• 2010

Sulfur metabolism in S. cerevisiae is well established, but the mechanisms underlying the formation of sulfide remain obscure. Here, we investigated by real-time RT-PCR the dependence of expression levels of MET3, MET5/ECM17, MET10, MET16, and MET17 along with SSU1 on nitrogen availability in two wine yeast strains that produce divergent sulfide profiles. MET3 was the most highly expressed of the genes studied in strain PYCC4072, and SSU1 in strain UCD522. The strains behaved differently according to the sampling times, with UCD522 and PYCC4072 showing the highest expression levels at 120 h and 72 h, respectively. In the presence of 267 mg assimilable N/l, the genes were more highly expressed in strain UCD522 than in PYCC4072. MET5/ECM17 and MET17 were only weakly expressed in both strains under any condition tested. MET10 and SSU1 in both strains, but MET16 only in PYCC4072, were consistently upregulated when sulfide production was inhibited. This study illustrates that strain genotype could be important in determining enzyme activities and therefore the rate of sulfide liberation. This linkage, for some yeast strains, of sulfide production to expression levels of genes associated with sulfate assimilation and sulfur amino acid biosynthesis could be relevant for defining new strategies for the genetic improvement of wine yeasts.

• Journal of Microbiology and Biotechnology
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• v.21 no.5
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• pp.455-463
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• 2011

Metallothioneins are a class of small cysteine-rich proteins that have been associated with increased tolerance to metal and oxidative stresses in animals, plants, and fungi. We investigated a metallothionein-like (mt-like) gene shown previously to be upregulated in fruiting bodies of the fungus Agaricus bisporus in response to post-harvest storage. Analysis of an A. bisporus genomic DNA cosmid library identified two similar mt-like genes (met1 and met2) arranged as a bidirectional gene pair transcribed from the same promoter region. The promoter contained regulatory elements including 9 metal responsive elements and a CAAT box region 220 bp downstream of met1 that showed striking similarity to a feature in Coprinopsis cinerea mt-like gene promoters. Transcriptional analysis showed that both met genes are significantly and rapidly (within 3 hours) upregulated during post-harvest storage and expression is significantly greater in stipe and cap tissues compared with the gills. However, a strong directionality of the promoter was demonstrated, as transcript levels of met1 were at least two orders of magnitude greater than those of met2 in all samples tested.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.373-378
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• 2004

The regulatory mechanism of methionine biosynthesis in Corynebacterium glutamicum was analyzed at the protein arid gene expression level. O-Acetylhomoserine sulfhydraylase (encoded by metY) was inhibited by 10 mM methionine to a residual activity of 10% level, whereas no such inhibition was found with cystathionine $\gamma$-synthase (encoded by metB) and cystathionine $\beta$-lyase (encoded by metC). The enzymatic activity of homoserine acetyltransferase (encoded by metX) was repressed to a residual activity of 25% level by 10 mM methionine which was added to the growth medium. Cystathionine $\gamma$-synthase and cystathionine $\beta$-lyase were also repressed by 10 mM methionine, but only to a residual activity of 50-70% level. O-Acetylhomoserine sulfhydrylase was very sensitive to repression by 10 mM methionine, showing residual activity of 13%. In addition, homoserine acetyltransferase was also repressed by 10 mM cysteine to 50% of its original activity. No repression of the enzymes by S-adenosyl methionine was observed. The pattern of repression by methionine indicated that the metB and aecD genes might be regulated by a common mechanism, while the metA and metY genes are differently regulated.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9621-9625
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• 2014

XRCC (X-ray cross-complementing group) genes contribute to important DNA repair mechanisms that play roles in the repair of single strand breaks (SSBs) induced by a variety of external and internal factors, including ionizing radiation, alkylating agents and reactive oxygen species. These repair genes have a pivotal role in maintaining genomic stability through different pathways of base excision repair (BER). The aim of this study was to investigate the XRCC3 Thr241Met gene polymorphism in colorectal cancer (CRC) in Kashmir. We investigated the genotype distribution of XRCC3 gene in 120 CRC cases in comparison with 150 healthy subjects and found a significant association between XRCC3 genotypes and CRC ($p{\leq}0.05$). Both heterozygous genotype (Thr/Met) as well as homozygous variant genotype (Met/Met) were moderately associated with elevated risk of CRC [OR=2.53; OR=2.29 respectively]. Also, Thr/Met and Met/Met genotypes demonstrated a significant association with the risk of CRC (p = 0.003). This study displayed a significantly elevated risk for CRC in individuals with XRCC3 Thr/Met and Met/Met Genotype of about 2.5 times that with the Thr/Thr wild genotype.

• Korean Journal of Biological Psychiatry
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• v.12 no.2
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• pp.216-220
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• 2005

Background:Brain-derived neurotrophic factor(BDNF) genes are thought to be important factors in some personality traits. The goal of this study was to determine the role of these genes in personality traits. Method:The participants included 170 healthy adults with no history of psychiatric disorders and other physical illnesses for the last 6 months. All participants were tested by the Temperament and Character Inventory (TCI). BDNF Val64Met gene polymorphisms were analyzed with PCR(Polymerase Chain Reaction). Differences on TCI dimensions and sub-scales among groups were examined with ANOVA. Result:There was a significant correlation between BDNF Val64Met and Persistence(PS)(p=0.036) in female subjects, but none with the other TCI dimensions. A post-hoc comparison revealed significant a difference between Val/Val and Met/Met (p=0.031). Conclusion:Our study suggests that the BDNF Val64Met gene polymorphism is associated with persistence in Korean female subjects, but the small number of subjects limits generalization of our results. Further studies with a larger number of homogenous subjects are needed to confirm whether the BDNF gene is related to personality traits.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1245-1252
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• 2022

Induced pluripotent stem cells (iPSCs) can be generated from somatic cells using Oct4, Sox2, Klf4, and c-Myc (OSKM). Small molecules can enhance reprogramming. Licochalcone D (LCD), a flavonoid compound present mainly in the roots of Glycyrrhiza inflata, acts on known signaling pathways involved in transcriptional activity and signal transduction, including the PGC1-α and MAPK families. In this study, we demonstrated that LCD improved reprogramming efficiency. LCD-treated iPSCs (LCD-iPSCs) expressed pluripotency-related genes Oct4, Sox2, Nanog, and Prdm14. Moreover, LCD-iPSCs differentiated into all three germ layers in vitro and formed chimeras. The mesenchymal-to-epithelial transition (MET) is critical for somatic cell reprogramming. We found that the expression levels of mesenchymal genes (Snail2 and Twist) decreased and those of epithelial genes (DSP, Cldn3, Crb3, and Ocln) dramatically increased in OR-MEF (OG2^+/+/ROSA26^+/+) cells treated with LCD for 3 days, indicating that MET effectively occurred in LCD-treated OR-MEF cells. Thus, LCD enhanced the generation of iPSCs from somatic cells by promoting MET at the early stages of reprogramming.

• Journal of Mushroom
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• v.2 no.3
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• pp.145-148
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• 2004

This study was carried out to screen the fruiting body formation-specific genes from the medicinal mushroom Cordyceps militaris. A cDNA synthesized using total RNA from 4 stages of mushroom development, mycelium, primordium, immature fruiting body and mature fruiting body. Differential expression gene screening was performed by DD-PCR(Differential Display Arbitrary Primer PCR) with cDNA, we sequenced partial 6 genes using pGEM cloning vector. The DNA Sequence of the six DD-PCR products derived from differentially expressed genes was compared to that in the GenBank database by using the NCBI BLAST search to identify similarities to known sequences. Sequence analysis showed that six of DD-PCR products have unknown sequence.

• Korean Journal of Head & Neck Oncology
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• v.21 no.1
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• pp.15-20
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• 2005

Objectives: The hepatocyte growth factor(HGF)/c-Met pathway may play various roles in the carcinogenesis of various organs. Although HGF/c-Met signalling pathway has been shown to demonstrate various cellular responses including mitogenic, proliferative, morphogenic and angiogenic activities, the study on their expression related to clinicopathological parameters in thyroid tumor is relatively rare. So we want to find out the clinical significance of the c-Met in thyroid tumor. Materials and Methods: We assess the mRNA and protein expression of the c-Met genes by means of RT-PCR method and the immunohistochemical stain in 100 cases of thyroid tumors(50 papillary carcinomas, 10 follicular carcinomas, 20 follicular adenomas, 20 nodular hyperplasia). Results: By RT-PCR, c-Met mRNA was detected in 43(86%) in papillary carcinoma, 4(40%) in follicular carcinoma, 4(20%) in follicular adenoma and 2(10%) in nodular hyperplasia cases. By immunohistochemistry, c-Met protein expression was detected in 44(88%), 2(20%), 3(15%) and 1(5%). Expression of the c-Met mRNA and protein expression was significantly highly recognized in papillary carcinoma. The c-Met protein overexpression was significantly correlated with the grade of the differentiation. Conclusion: These results suggest that c-Met expression may be associated with thyroid papillary cancer progression. The differential expression of c-Met protein and mRNA suggests that these molecules may be a reliable diagnostic marker in thyroid papillary cancer.

• Journal of Applied Biological Chemistry
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• v.48 no.3
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• pp.113-119
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• 2005

O-methylation mediated by O-methyltransferases (OMTs) is a common modification in natural product biosynthesis and contributes to diversity of secondary metabolites. OMTs use phenylpropanoids, flavonoids, other phenolics and alkaloids as substrates, and share common domains for S-adenosyl-L-methionine (AdoMet) and substrate binding. We searched Arabiposis genome and found 17 OMTs genes (AtOMTs). AdoMet- and substrate-binding sites were predicted. AdoMet binding domain of AtOMTs is highly conserved, while substrate-binding domain is diverse, indicating use of different substrates. In addition, expressions of six AtOMT genes in response to UV and in different tissues were investigated using real-time quantitative reverse transcriptase-polymerase chain reaction. All the AtOMTs investigated were expressed under normal growth condition and most, except AtOMT10, were induced after UV illumination. AtOMT1 and AtOMT8 were expressed in all the tissues, whereas AtOMT10 showed flower-specific expression. Analysis of these AtOMT gene expressions could provide some clues on AtOMT involvement in the cellular processes.