• The Korean Journal of Physiology and Pharmacology
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• v.4 no.2
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• pp.129-135
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• 2000

Previously, we have reported that ${\rho}-chlorophenylalanine$ (PCPA), a serotonin depletor, profoundly increased pancreatic fluid and bicarbonate secretion but remarkably inhibited pancreatic amylase secretion in anesthetized rats. The present study was performed to verify the detailed effects of PCPA on pancreatic amylase synthesis that is directly related to amylase exocrine secretion. PCPA significantly decreased pancreatic RNA and protein contents as well as the amylase activity. However, pancreatic DNA content, trypsin and chymotrypsin activities were not influenced by the treatment of PCPA. The rate of pancreatic amylase synthesis, which was assessed by the amount of incorporated $[^{35}S]-methionine$ into amylase for 1 h, was also significantly decreased by 44% in PCPA-treated rats. In order to determine whether the PCPA-induced decrease of amylase synthesis resulted from change in the level of amylase mRNA, Northern blot analysis was performed. The mRNA expression level of amylase was also decreased by 48% in the PCPA-treated rats, indicating that the inhibitory effect of PCPA on the synthesis of pancreatic amylase was mainly regulated at a step prior to translation. It was also revealed in SDS-polyacrylamide gel electrophoresis that the qualitative change of amylase was induced by PCPA. The 54 KDa amylase band seems to be degraded into small molecular weight protein bands in PCPA-treated rats, suggesting that the PCPA- induced decrease of amylase may be partly attributed to the degradation of synthesized amylase.

• Development and Reproduction
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• v.4 no.1
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• pp.125-131
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• 2000

This study has used differential display-PCR, to amplify genes transcribed during the ovarian maturation induced by human chorionic gonadotropin (hCG). The cDNA expressed at the times of acquisition of oocyte maturational competence in red seabream (Pagrus major) following treatment with hCG was amplified and cloned. A full-length of cDNA for p. major was isolated using differential display-PCR and 5'RACE. This cDNA clone contained 2,662 nucleotides including the open reading frame that encoded 434 amino acids. Homology analyses, using the GenBank and EMBL general database searches, indicated that the nucleotides sequence of the cDNA does not have high homology with any other genes. This cDNA was judged to be a gene, which induction of maturational competence coincides with increase of mRNA related ovarian maturation. Consensus sequences which were consistent with protein kinase C phosphorylation sites and casein kinase II phosphorylation sites were identified. in vitro, the transcription level of mRNA related ovarian maturation increased between 9hr and 24hr following treatment of ovarian follicles with hCG. It was also increased after GtH-II (300 ng/ml) stimulation. Furthermore, in vivo, mRNA related ovarian maturation was rarely expressed prior to the acquisition of oocyte maturational competence, but was strongly expressed after the acquisition of oocyte maturational competence, suggesting that the hCG induction of maturational competence is brought about by the de novo synthesis of the mRNA related ovarian maturation in p. major.

• Korean Journal of Plant Tissue Culture
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• v.24 no.1
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• pp.1-35
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• 1997

Fertilized egg, by successive cell divisions, differentiates into different tissues and organs with various structures and functions. Different cells and tissues contain different proteins, products of selective gene expression. Not all the genes in any genomes are equally active, temporal and spatial gene expression being the general rule. Present paper attempts to review the tanscriptional mechanisms or the initiations of transcription from several angles. In some of the organisms the genes in the process of transcription or the genes in the inactive state can be seen under the light microscope. Some bands of Drosophila polytene chromosomes may exhibit a swollen or puff appearance under certain conditions. A puff, unfolded or decondensed form of chromomere, represents sets of intense transcriptional activity or RNA synthesis. The heterochromatic X chromosome whose genes remain inactive in the female mammals can be visualized as a dark staining structure called Barr body, Configuration of chromatin differs between transcribed and nontranscribed chromatin. Modification to the chromatin facilitates RNA synthesis. The movement of large polymerase molecule along the DNA would probably be facilitated if some modifications of the chromatin configuration is effected. Methylation of cytosines in CG sequences is associated with inactive genes. Methylation can play a role in determination of mammalian cells during embryogenesis. Demethylation is necessary for the gene to be expressed during development A histone modification that is also known to be correlated with transcriptional capacity of chromatin is acetylation of the lysine residues of the core histones. Chromatin containing a high level of histone acetylation is very sensitive to DNase 1. For the transcription to occur TBP must first bind to the TATA box. Another TF, TF IIB, then binds to the promoter-TBP complex, facilitating the access of RNA polymerase to the transcription initiation site. As recently as eight years ago researchers assumed that histones were irrelevant to the regulation of gene expression. Histones combine with the DNA to form nucleosome of the chromatin. Histones are vital participant in gene regulation. Histone and basal factors compete for access to TATA box. When DNA is exposed to basal factors before histones are introduced, the basal factors assemble on TATA boxes preventing the access of histones, allowing transcription to occur, for transcription to begin, activator protein at the upstream activation sequence or enhancer must interact with the tail of histone H4 at TATA box and cause the histone role particle to dissociate from the TATA box leading to partial breakup of the histone core particle and allowing the basal factors to bind to the TATA box. New concept of genomic flux in contrast to the old concept of static genome has been developed based on the powerful new molecular techniques. Genomic changes such as repetitive DNAs and transposable elements, it is assumed but not yet proved, may affect some of the developmental patterns that characterize particular cells, tissues, organs, and organisms. In the last decade or so remarkable achievement have been made in the researches of the structures and functions of TFs and the specific target sequences located in promoters or enhancers where these TFs bind. TFs have independent domains that bind DNA and that activate transcription. DNA binding domain of TFs serves to bring the protein into the right location. There are many types of DNA binding domains. Common types of motifs can be found that are responsible for binding to DNA. The motifs are usually quite short and comprise only a small part of the protein structure. Steroid receptors have domains for hormone binding, DNA binding, and activating transcription. The zinc finger motif comprises a DNA binding domain. Leucine zipper consist of a stretch of amino acids with a leucine residue in every seventh position Two proteins form a dimer because they interact by means of leucine zippers on similar α-helical domain. This positions their DNA binding basic domains for interaction with the two halves of a DNA sequence with dyad symmetry of TGACTCA, ACTGAGT.

• Environmental Mutagens and Carcinogens
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• v.22 no.3
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• pp.205-210
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• 2002

In irradiated human lymphocytes, translocation of chromosome has been more frequently observed than dicentric chromosome. Differences in the misrepair process leading to translocation and dicentric chromosomes may explain the above observations. In order to find out whether dicentric and translocation are originated from different mechanism, the frequencies of radiation induced translocation and dicentric in lymphocytes were examined following treatment of irradiated lymphocytes with two DNA repair inhibitors, 3AB for inhibition of poly(ADP-ribose) synthesis and Ara C for inhibition of DNA-polymerase $\alpha$. Ara C potentiated the frequencies of radiation induced dicentric and translocation. 3AB also potentiated the frequencies of radiation induced dicentric, but not translocation. These results suggest the potential differences in the mechanisms in the formation of translocation and dicentric chromosomes.

• BMB Reports
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• v.32 no.6
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• pp.554-560
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• 1999

TTD1BI cells are non-hypersensitive to UV irradiation and perform normal genome repair of pyrimidine dimers but fail to excise 6-4 photoproducts and, concomitantly, are unable to restore RNA synthesis levels following UV irradiation. This pointed to a detect in gene-specific repair and this study was undertaken to examine repair of 6-4 photoproducts at the gene-level. The results indicated a defect in gene-specific repair of 6-4 photoproducts in active genes, although strand-specificity of 6-4 photoproduct removal was essentially similar to that of normal cells. These findings indicate that the near normal UV resistance of TTD1BI cells may be due to the inability of these cells to remove DNA lesions preferentially, as well as to the cells opting out of the cell cycle to repair damage before resuming replication.

• Korean Journal of Microbiology
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• v.4 no.1
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• pp.14-20
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• 1966

1. Uniformly $^{32}P$-labeled Chlorella cells were further grown in a standard "cold" medium and aliquots of the algal cells were taken out at the beginning of, and at intervals during the culture, and subjected to analyze the contents of $^{32}$ P and total P in various fractions of the cell constituents. 2. When the $^{32}P$--labeled algae were grown in a normal "cold" medium, the P-contents in the fractions of DNA and protein increased. In the meantime the $^{32}P$- in acid-insoluble polyphosphate fraction decreased considerably, while that in RNA-polyphosphate complex significantly increased. 3. It was inferred that, under the experimental conditions of the present study, the phosphorus in polyphosphate seems to be transferred to RNA polyposphate complex and the phosphorus used in the synthesis of DNA and protein was, directly or indirectly, taken from those fractions above.ose fractions above.

• Journal of Microbiology and Biotechnology
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• v.1 no.4
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• pp.251-255
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• 1991

A 16 kilobase (kb) HindIII fragment of alkalophilic Bacillus sp. YC-335 containing a gene for xylanase synthesis was inserted at the HindIII site of pBR322 and cloned in Escherichia coli HB101. After subcloning of recombinant plasmid pYS52, the 1.5 kb fragment was found to code for xylanase activity, and the hybrid plasmid was named pYS55. The DNA insert of the plasmid was subjected to restriction enzyme mapping, which showed that pYS55 had single site for PuvII and SstI in the 1.5 kb insert fragment. Southern hybridization analysis revealed that the cloned gene was hybridized with chromosomal DNA from alkalophilic Bacillus sp. YC-335. About 64% of the enzyme activity was observed in the extracellular and periplasmic space of E. coli HB10l carrying pYS55.

• Animal cells and systems
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• v.8 no.2
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• pp.105-109
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• 2004

Aminoalcoholphosphotransferase catalyzes the synthesis of phosphatidylcholine and phosphatidylethanolamine from diacylglycerol plus a CDP-aminoalcohol such as CDP-choline or CDP-ethanolamine. Previously we suggested the presence of possible isoforms of this enzyme from Chinese cabbage roots and now report the cDNA cloning and expression analysis of AAPT3 encoding a third isoform of aminoalcoholphosphotransferase (AAPT3). AAPT3 contains an open reading frame of 1,176 bp coding for a protein of 392 amino acids. It shares 96 and 95% identity with Chinese cabbage AAPT1 and AAPT2, respectively, at the deduced amino acid level. The results from reverse transcriptase-polymerase chain reaction analysis indicate that expression of AAPT3 is up-regulated by low temperature as well as AAPT1 and AAPT2.

• Proceedings of the Korean Biophysical Society Conference
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• 2001.06a
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• pp.22-22
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• 2001

At the eukaryotic replication fork, discontinuous synthesis of lagging strand DNA gives rise to Okazaki fragments carrying ribonucleotides derived from the primer RNA at their 5' ends. Efficient removal of these ribonucleotides is vital for maintaining genome integrity. In this report we show that the endonucleases Dna2 and Fen1 act sequentially to facilitate the complete removal of the primer RNA.(omitted)

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.19-49
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• 1987

Recent development of recombinant DNA techniques such as gene cloning and DNA sequencing has led to understanding of genetic information coded on plant genes and their application to crop improvements. Nuclear genes so far isolated and characterized at the molecular level from various plants are those involved mainly in photosynthesis, nitrogen fixation, seed development and defensive responses to environmental stresses. Most of plant genes contain intervening sequences (introns) flanked with GT and AG, as it typical of animal genes. The 5' flanking regions of plant gene revealed the presence of promoter elements such as TATAAA and CCAAT, which have been identified at animal genes to be involved in transcrip- tion initiation. The 3' untranslated regions include a sequence similar to AATAAA whcih functions as a polyadenylation signal in other eukaryotic genes. Furthermore, enhancer-type sequences were found at the 5' flanking regions of various plant genes. This indicates that the structure of plant genes is very similar to animal genes and mechanisms governing the synthesis and processing of mRNAs may be identical in higher eukaryotes. However, genes expression studies involving transformation revealed their differ ences within plants and between plant and animal systems.