• Korean Journal of Plant Tissue Culture
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• v.21 no.2
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• pp.99-103
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• 1994

The herbicide bialaphos is a potent inhibitor of glutamine synthetase in higher plants. A bialaphos resistance (bar) gene encoding for an acetyltransferase was isolated from genomic DNA of Pseudomonas syringae pv tabaci. The bar gene was ligated to the binary vector pBI121. Pistils of tobacco plane were heated with the bar gene containing plasmid DNA at various times after pollination. When the treatment was applied at 30 and 40 h after pollination, a number of transgenic plants were obtained. Premary transformation (T$_{0}$ generation) and their progenies (T$_1$T$_2$) were resistant to both bialaphos and kanamycin at a dosage lathal to untransformed control plants. Stable integration of bar gene into chromosomal DNA was proven by Southern blot analysis of genomic DNA isolated from T$_1$progenies. These results show that the bialaphos resistant plane could be obtained by treatment to pistils with the exgenous bar gene through the fertilization cycle of tobacco.o.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.352-355
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• 2003

To investigate the protective effect of Gamdu-tang(GDT) and its constituents. Radix Glycyrrhizae(RG) and Semen Glycine(SG) on the damage of cardiac endothelial cells by xanthine oxidase (XO)/hypoxanthine (HX)-induced oxygen free radical, Neutral Red (NR) and DNA synthesis assay were used. The results were obtained as follows ; Cardiac endothelial cells treated with XO/HX showed the cytotoxicity such as decreases in viability and DNA synthesis. Cardiac endothelial cells pretreated with GDT extracts were not showed the decrease of DNA synthesis by XO/HX, These results show that XO/HX elicits toxic effects in cultured cardiac endothelial cells derived from neonatal rat, and suggest that GDT extract is very effective in the prevention of XO/HX-induced toxicity.

• Journal of Sericultural and Entomological Science
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• v.38 no.2
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• pp.186-188
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• 1996

곤충애 있어서 호르몬의 작용기작과 그 이용에 관하여 요야하면 다음과 같다. 곤충호르몬에는중추신경계의 신경분비세포에서 합성, 분비되는 peptide의 neuropeptide hormone (PTTH, bombyxin, diapause hormone등)이 있고, 상피계의 내분비선에서 합성, 분비되는 sesquiterpene의 유약호르몬 ( juvenile hormone)과 steroid의 탈피호르몬 (ecdysone)이 있다. 곤충호르몬은 특정한 표족세포에 있는 수용체와 높은 특이성과 높은 친화성을 가지고 결합해서 세포의 작용을 조절한다. 일반적으로 peptide hormone은 표적세포의의 세포막을 통과할 수 없으므로 표적세포의 막표면에 있는 수용체와 결합하는 것에 의해 세포내 대사제를 활성화시킴으로서 peptide hormone의 특이적인 발현이되는 것으로 알려지고 있다. 한편, ecdysone과 같은 steriod hormone이나 juvenlie hormone은 표적세포의 세포막을 용이하게 통과할수 있으므로 세포내의 세포막을 용이하게 통과할 수 있으므로 세포내로 들어가 수용체와 결합해서 hormone-receptor comlpex는 핵내로 들어가 DNA의 특이적인 영역에 결합하므로서 이들 호르몬 특이적인 기능이 발현되는 것으로 알려져 있다. Ecodysone의 활성이 있는 ecdysteroid가 여러 식물에서 발견되고 있어, 금후 양잠의 상족에 이용이 기대되고 있다. 또한, 향유약호르몬(AJH) 활성물지인 imidazole계 화합물은 양잠에 있어서 세섬도고치 생산에 그 이용이 기대되고 있다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.16-16
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• 1992

1940년대에 처음으로 암의 화학요법이 시도된 이래 많은 항암제들이 도입되어 사용되고 있다. 현재 항암제를 사용하여 비교적 치료율이 높은 암은 leukemia나 lymphoma와 같은 혈액암에 국한되어 있다. 고형암에 대하여는 고환암과 같은 극히 일부가 항암제에 의해 비교적 잘 치료되나 대부분은 여전히 치료가 되지 않고 있는 상태에 있다. 고형암의 발생빈도는 전체 암의 90％를 차지하고 있는 상태로 사망율이 매우 높아, 현대의 40대 이상 사망원인의 1위를 나타내고 있어 그 치료제의 개발이 매우 시급히 요구되고 있다. 이에 따라 고형암의 치료를 목적으로 많은 화합물들이 검토되어 왔다. 이중 최근 매우 큰 가능성을 보여주고 있는 diarysulfonylurea 유도체가 발견되어 임상시험에 도입됨으로서 이 화합물들에 대한 관심이 고조되고 있다. 이와 관련하여 고형암의 치료제를 개발할 목적으로 diarysulfonylurea의 특성과 강력한 항암효과를 발현하는 alkylating agent의 특성을 갖을 것으로 예상되는 새로운 2-alkoxy-1-arylsufonylimidazoline 유도체를 설계하고, 이들 유도체의 합성법을 개발하였다. 이들 유도체들은 일차적으로 생체내에서 DNA 또는 효소등에 alkylation을 일으킨후 diarysulfonylurea로 변하여 작용함으로서 보다 큰 항암효과를 발현할 것으로 기대된다.

• Journal of Life Science
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• v.7 no.3
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• pp.180-185
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• 1997

Methylelaiophylin generated superoxide radicals in Bacillus subtilis and showed antibacterial activity against a broad range of gram positive bacteria. The inhibition of DNA synthesis was more sensitive than one of RNA synthesis. A recombination-deficient mutant strain of B. subtilis was 2-fold more sensitive than a wild strain, and this sensitivity was reduced in the presence of an antioxidant, dithiothreitol. Methylelaiophylin generated superoxide radicals in B. subtilis lysates, and this suggests that the antibacterial activity of methylelaiophylin is related to the generation of active oxygen species in the cells.

• KSBB Journal
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• v.7 no.3
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• pp.155-160
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• 1992

To improve the nutritional quality of plant proteins, a synthetic gene, called HEAAE (high essential amino acid encoding)-DNA, was introduced and expressed in tobacco plants. The synthetic gene, which is 292 basepair-long, codes for a protein composed of about 80% essential amino acids. To improve its expression level in plants, Cauliflower Mosaic Virus (CaMV) 355 and CaMV duplicate 35S promoters which are known as strong promoters were used with Nopaline Synthase promoter as a control. Transformed and regenerated tobacco plants were subject to analysis for introduction and expression of this gene. Integration of the gene into the plant genome and its expression into mRNAs and its proteins have been demonstrated using Southern, northern blot analysis and amino acid analysis. The differences of expression levels among CaMV duplicate 35S, CaMV 35S and Nopaline Synthase promoters are significant in term of mRNAs, but not in terms of proteins.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.303-309
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• 1990

In order to have a handle on the availability of eukarvotic peptide hormone precursors, a cDNA encoding angler fish prepro-SRIF I was manipulated so that it can be produced in large quantity from heterologous E. coli cells. Using T7 overexpression system, fusion constructs between the T7 phage coat protein Sl0 and the prepro-SRIF were made and modified as desired. From the host E. coli strain, BL21 DE3, harboring these plasmid constructs, three different SRIF related polypeptides were expressed in large amount and characterized. The results confirm the exact construction and authenticity of the overexpressed proteins from E. coli cells. The importance of this heterologous overexpression in hard to get peptide hormone precursors as well as the suitability of the target peptide hormone SRIF for this approach are discussed.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.734-742
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• 2012

To compare RNA interference-mediated gene silencing technique and T-DNA integration for gene function analysis in Chinese cabbage, BrSAMS-knockout (KO) line and BrSAMS-knockdown (KD) line were used. The KO line had lost the function of a Brassica rapa S-adenosylmethionine synthetase (BrSAMS) gene by T-DNA insertion and the KD line had shown down-regulated BrSAMS genes' expression by dsRNA cleavage. From microarray results of the KO and KD lines, genes linked to SAMS such as sterol, sucrose, homogalacturonan biosynthesis and glutaredoxin-related protein, serine/threonine protein kinase, and gibberellin-responsive protein showed distinct differences in their expression levels. Even though one BrSAMS gene in the KO line was broken by T-DNA insertion, gene expression pattern of that line did not show remarkable differences compared to wild type control. However, the KD line obtained by RNAi technique showed prominent difference in its gene expression. Besides, change of polyamine and ethylene synthesis genes directly associated with BrSAMS was displayed much more in the KD line. In the microarray analysis of the KO line, BrSAMS function could not be clearly defined because of BrSAMS redundancy due to the genome triplication events in Brassicaceae. In conclusion, we supposed that gene knock-down method by RNAi silencing is more effective than knock-out method by T-DNA insertion for gene function analysis of polyploidy crops such as Chinese cabbage.

• The Korean Journal of Pharmacology
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• v.24 no.1
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• pp.1-10
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• 1988

To obtain information about the structure of the human phenylethanolamin N-methyltransferase (PNMT) and to further define the extent of the evolutionary relationships among PNMT molecules of several spesies, a full length cDNA clone for bovine adrenal PNMT was used to screen a charon 4A genomic library. One phage was isolated and identified, which included the entire PNMT gene. The length of inserted genomic DNA was 13.1-Kilobase (Kb) containing two internal EcoRI sites. Construction of a restriction map and subsequent Southern and dot blot analysis with 5'-and3'-specific cDNA probes allowed the identification of exon-containing fragments. This is the first report of the cloning of gene for human epinephrine synthesizing enzyme.

• Applied Biological Chemistry
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• v.39 no.2
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• pp.112-117
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• 1996

Arginine decarboxylase (ADC) is the first enzyme in one of the two pathways of diamine putrescine biosynthesis in plants. The genes encoding ADC have previously been cloned from Escherichia coli, oat and tomato genome. Two degenerate oligonucleotides (17-mer) corresponding to two conserved regions of ADC were used as primers in polymerase chain reaction of rice (Oryza sativa L.) genomic DNA, and an approximately 1.0 kbp fragment was obtained. This amplified PCR product showed an open reading frame which contains 1,022 bp of nucleotide sequences. This PCR product was cloned into pGEM-originated T vector and the short 500 bp PstI digested fragment was subcloned into pGEM-3zf(+/-) vectors to facilitate sequencing. The nucleotide sequence of this PCR product showed about 74% and 70% identity with the same regions of the oat and tomato ADC cDNA sequences, respectively. The predicted amino acid sequence exhibited 45% and 62% identity with oat and tomato ADC polypeptide fragments, respectively. The sequence similarities of 34%, 47% and 38% were previously reported in oat and E. coli, tomato and oat, and tomato and E. coli ADC amino acids, respectively. Therefore, similarities and identities between rice and oat or tomato are remarkably higher than those others of the previous reports. In the highly conserved regions in both the amino acid sequence and spacing regions among the sequences of these three, rice ADC open reading frame also has the exactly same regions with the striking similarity. RNA blot analysis showed that hnc is expressed as a transcript of approximately 2.5 kbP in the rice seedling leaf tissues.