• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3770-3772
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• 2011

• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.4265-4266
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• 2012

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.465-474
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• 1999

RNase activity of Saccharomyces cerevisiae ATCC 7754 was investigated to obtain strains with high ribonucleic acid (RNA) content. The yeast strain contained two RNase activities; an acidic RNase with a optima of pH $3{\sim}4$ and an alkaline RNase with a optima pH 9. The acidic RNase activity was inhibited by $0.08\;M\;HgCl_{2}$ most drastically. The alkaline RNase activity was inhibited by 2.0 M NaCl or KCl, while enhanced by addition of $0.05\;M\;CaCl_{2},\;0.02\;M\;ZnSO_{4},\;or\;0.008\;M\;HgCl_{2}$. Various mutants of Saccharomyces cerevisiae ATCC 7754 were isolated by ethylmethane sulfonate (EMS) treatment or $\gamma$-ray/ultra violet irradiation. Among the mutants that were sensitive to high concentration of KCl which inhibits alkaline RNase, B24 was selected for high RNA content per culture volume. Growth characteristics of the mutant were comparable to those of the mother strain with optimum growth at pH $4.5{\sim}5.5$. The mutant accumulated higher content of RNA than the mother strain when glucose was used as the carbon source. However, both growth rate and total RNA content of the mutant were higher in molasses medium than in glucose medium. RNA content of the mutant increased rapidly during the early stage of growth, and then decreased gradually until the culture reached stationary phase by a fed-batch culture in a 5 L jar fermenter. Maximal cell harvest and the final RNA content using the mutant B24 were 69.6 g/L culture broth and 19.8 g/100 g of the dry cell while those using the mother strain were 68 g/L culture broth and 16.1 g/100 g of dry cell, respectively.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.1
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• pp.15-20
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• 2018

Most proteins produced in the endoplasmic reticulum (ER) of eukaryotic cells fold via disulfide formation (oxidative folding). Oxidative folding is catalyzed by protein disulfide isomerase (PDI) and PDI-related ER protein thiol disulfide oxidoreductases (ER oxidoreductases). In yeast and mammals, ER oxidoreductin-1s (ERO1s) supply oxidizing equivalent to the active centers of PDI. We previously identified and characterized the ERO1 of Bombyx mori (bERO1) as a thioredoxin-like protein that shares primary sequence homology with other ERO1s. Here we compare the reactivation of inactivated rRNase and sRNase by bERO1, and show that bERO1 and bPDI cooperatively refold denatured RNase A. This is the first result suggesting that bERO1 plays an essential role in ER quality control through the combined activities of bERO1 and bPDI as a catalyst of protein folding in the ER and sustaining cellular redox homeostasis.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.325-330
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• 2007

RNase E is an essential Escherichia coli endoribonuclease that plays a major role in the decay and processing of a large fraction of RNAs in the cell and expression of N-terminal domain consisted of 1-498 amino acids (N-Rne) is sufficient to support normal cellular growth. By utilizing these properties of RNase E, we developed a genetic system to screen for amino acid substitutions in the catalytic domain of the protein (N-Rne) that lead to various phenotypes. Using this system, we identified three kinds of mutants. A mutant N-Rne containing amino acid substitution in the S1 domain (I6T) of the protein was not able to support survival of E. coli cells, and another mutant N-Rne with amino acid substitution at the position 488 (R488C) in the small domain enabled N-Rne to have an elevated ribonucleolytic activity, while amino acid substitution in the DNase I domain (N305D) only enabled N-Rne to support survival of E. roli cells when the mutant N-Rne was over-expressed. Analysis of copy number of ColEl-type plasmid revealed that effects of amino acid substitution on the ability of N-Rne to support cellular growth stemmed from their differential effects on the ribonucleolytic activity of N-Rne in the cell. These results imply that the genetic system developed in this study can be used to isolate mutant RNase E with various phenotypes, which would help to unveil a functional role of each subdomain of the protein in the regulation of RNA stability in E. coli.

• Animal cells and systems
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• v.1 no.2
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• pp.363-370
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• 1997

RNase MRP is a ribonucleoprotein complex with a site-specific endonuclease activity. Its original substrate for cleavage is the small mitochondrial RNA near the mitochondrial DNA replication origin, thus it was proposed to generate the primer for mtDNA replication. Recently, it has been shown to have another substrate in the nucleus, such as pre-S.8S ribosomal RNA in nucleolus. The gene for the RNA component of RNase MRP (MRP RNA) was found to be encoded by the nucleus genome, suggesting an interesting intracellular trafficking of MRP RNA to both mitochondria and nucleolus after transcription in nucleus. In this study, genomic DNA encoding MRP RNA was microinjected into the nucleus of Xenopus oocytes, to analyze promoter regions involved in the transcription. It showed that the proximal sequence element and TATA box are important for basal level transcription; octamer motif and Sp1 binding sites are for elevated level transcription. Most of Xenopus MRP RNA was exported out to the cytoplasm following transcription in the nucleus. Utilizing various hybrid constructs, export of MRP RNA was found to be regulated by the promoter and the 5' half of the coding region of the gene. Interestingly, the transcription in nucleus seems to be coupled to the export of MRP RNA to cytoplasm. Intracellular transport of injected MRP RNA can be easily visualized by whole-mount in situ hybridization following microinjection; it also shows possible intra-nuclear sites for transcription and export of MRP RNA.

• Microbiology and Biotechnology Letters
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• v.25 no.5
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• pp.512-519
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• 1997

RNA accumulating strain of Torulopsis versatilis MT-1 was cultured in molasses medium for higher contents of RNA in cell. Yeast cells were harvested at logarithmic phase on synchronous culture. Yield of cells on dry base to input sugar was 59.5%. Crude protein content was 55.1% in cell. RNA content was 13.9%. Some problems found in the process for the preparation of yeast extracts were improved by the addition of culture broth of Streptomyces faecalis MSF which secrete RNase (5' nuclease and 5' adenylic acid deaminase). When the culture broth of S. faecalis MSF was added in autolysis process 46% of RNA in cell was converted to I and G(5' inosinic acid and 5' guanylic acid) in extract. By addition of 3-7% culture broth of S.faecalis MSF in autolysis or enzymolysis process at the start or early stage, RNA in extract was converted easily to I and G and protein in cells was easily extracted and hydrolyzed to amino acid. Taste of those yeast extracts was delicious. The yeasty smell in yeast extracts was removed. And cell debris was easily removed from extract.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.368-374
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• 2011

Apricot (Prunus armeniaca L.) cultivars show a gametophytic self-incompatibility (GSI) system, like other fruit species of Rosaceae family. Thus, it is necessary to determine their S-genotypes in order for stable fruit set in commercial cultivation. S-genotypes of apricots were determined by PCR and test crosses. Three sets of consensus primers designed from Prunus S-RNases were used to amplify fragments containing the first and second S-RNase intron, respectively. Through the results obtained from the 3 PCRs, we could identify SI genotypes of 33apricot cultivars. Several cultivars such as 'Heiwa', 'Yamagata No.3' and 'Shinsuoomi' had the self-compatible (Sc) allele. Self-pollination tests revealed that cultivars with Sc allele were self-compatible. Cross-pollination tests confirmed that there was cross-incompatibility between the cultivars with the same S-genotypes. These results might be very useful for growers for effective pollination and for breeders using these in cross breeding programs.

• The Korean Journal of Zoology
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• v.20 no.1
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• pp.9-18
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• 1977

RNA was extracted from the eggs of Xenopus laevis to do preliminary experiments before testing the possibility that if RNase resistant RNA molecules exist in the amphibian egg. Chromatography on Sephadex G-100 column indicated 3 peaks consistently. Only high molecular weight RNA species eluted in the first peak were labeled in vitro using $^{3}H$-dimethyl sulfate to eliminate the possible contribution of base paired oligonucleotides from tRNA. By this method, high specific activity could be obtained and the attached methyl groups were quite stable.

• Journal of the Korean Chemical Society
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• v.65 no.2
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• pp.121-124
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• 2021

RNA molecules which bind to the G-rich sequence in the 5'-UTR RNA which plays an important role in expression of N-ras, were selected. The secondary structures of five selected RNA aptamers including primer sequence were found by the CLC RNA workbench ver. 4.2 program (www.clcbio.com) and investigated with RNA structural probes such as RNase T1 which has specificity for a G in single-stranded region, RNase V1 specific for double strand and nuclease S1 specific for single strand. The generalized secondary structure model was proposed and characterized. It was composed of a central long double strand region flanked by single strand region at both end sides. The double strand region had an internal single-strand region and bulges. The single strand loop in the right side was composed of four or five nucleotides.