• Development and Reproduction
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• v.4 no.1
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• pp.87-93
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• 2000

Equine chorionic gonadotropin (eCG) consists of highly glycosylated noncovalently linked $\alpha$- and $\beta$-subunits and belongs to the glycoprotein hormone family that includes lutropin (LH), follitropin (FSH), and thyrotropin (FSH). eCG is a unique member of the gonadotropin family because it elicits response characteristics of both FSH and LH in other species than the hone. eCG is synthesized and secreted by trophoblastic cells of the endometial cups between 40 and 130 days of gestation. In the present study, mRNA expression ratio of eCG, eLH and eFSH $\alpha$- and $\beta$-subunints was investigated in the placenta and pituitary. mRNA was extracted from equine placenta on day 70 of gestation and from pituitary of male horse (27 month-old). When the expression of both subunit mRNAs of eCG in the equine placenta was compared by Northern blotting, the expression of the $\beta$ -subunit mRNA was relatively greater than that of the $\alpha$-subunit. And mRNA expression of $\alpha$-, LH $\beta$- and FSH $\beta$-subunits was analysed in the equine pituitary. An $\alpha$-subunit was revealed with a size of approximately 0.8 kb. FSH $\beta$-subunit mRNA also was detected out 1.8 kb. It is the same size of the FSH $\beta$ -subunit mRNA cloned. The intensity of $\alpha$-subunit mRNA was greater than that of the $\beta$-subunit suggesting that the expression of $\alpha$ -subunit was dominant in the equine anterior pituitary. Thus, the subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$- and $\beta$-subunits in the equine placenta and pituitary.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.222-231
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• 1989

Three classes of proteinase inhibitors are known in soybean; the Kunitz trypsin inhibitor (SKTI), the Bowman-Birk proteinase inhibitor and its isoinhibitors. To study the molecular structure and expression characteristics of the SKTI, antibody was obtained by immunizing rabbit with the SKTI purified from soybean by preparative electrophoresis. Anti-SKTI antibody was not only specific for mature SKTI in soybean seed but also recognized the precursor which was synthesized in vitro. Translation in vitro was carried out in wheat germ extract with polyadenylated mRNA isolated from developing soybean seeds. One of the seed specific translation products, MW 24K, was identified to be the precursor for the SKTI by immunoprecipitation with anti-SKTI antibody. Mature SKTI of MW 20K, however, was not detected in the translates in vitro. These results suggest that the precursor polypeptide is synthesized from the mRNA and is cleaved to yield mature SKTI in soybean seed. The SKTI gene was expressed with the maturation of soybean seed in a tissue-specific and development stage-specific manner.

• Korean Journal of Plant Tissue Culture
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• v.21 no.2
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• pp.111-115
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• 1994

Two different gravity specific cDNA, namely, GSC 13 and GSC 124 with length of 1.34 and 0.67 kilobase pairs, and transcripts of 2.0 and 1.9 kilobase pairs, respectively. were isolated by differential screening and northern hybridization of the total RNA isolated from treated and untreated cultured cells showed that maximum levels of trannscripts were achieved after 4 h of gravity stress at 450, 000 x g for both, GSC 13 and GSC 124, suggesting that these mRNA could be expressed and translated into polyeptites related to the cell to extream gravity stress.

• Korean Journal of Microbiology
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• v.25 no.1
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• pp.23-27
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• 1987

Low molecular weight plant ribonucleic acids including viroid-RNA molecules which are soluble in 2M lithium chloride were electrophoresed in the 0M to 8M urea-gradient polyacrylamide gel. Although the linear viroid-RNA molecules migrated at a similarrate across the urea-gradient gel under the denaturing temperature, the circular viroid-RNA molecules moved more rapidly at low urea-gradient region than at high urea-gradient region. Consequently, the migration of the circular viroid-RNA molecules showed a sudden shift across the band of linear forms in the midrange of the urea-gradient gels. Electrophoretic mobilities of the circular viroid-RNA molecules seemed to depend mainly on the concentration of urea in the denaturing urea-gradient gels.

• Reproductive and Developmental Biology
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• v.30 no.3
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• pp.181-187
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• 2006

In recent years the number of patients waiting for organ transplantation has greatly outpaced the supply of human organs available, which leads to a renewed interest in pig-to-human xenotransplantation as an alternative. However, one of the biggest barriers in the xenotransplantation is presence of porcine endogenous retroviruses(PERV) that can infect human cells. In this study, to present a possible solution for this problem we tried to inhibit expression of PERVs using shRNAs(short hairpin RNA) at the level of RNA synthesis and virus release. The shRNA targeting the sequence of PERV A, B type was cloned into pSIREN-RetroQ vector under the control of polymerase-III U6-RNA gene promoter. Quantitative real-time PCR was performed to detect my alterations in mRNA production of PERV A, B targeted by the shRNA in each done. Depending on the target sequence of the shRNA, the transcription of PERV was decreased to as much as 4% and the number of progeny viruses was reduced to less than 1/200,000. Transgenic pigs producing such shRNAs may result in a highly reduced PERV expression in cells and organs, which is a prerequisite for safe xenotransplantations.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.309-319
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• 2018

Previously, six Schizosaccharomyce pombe mutants that induce pheromone even in the presence of nitrogen source were isolated from a bank of temperature sensitive mutants. In this report, one of these mutants, pws6 was further characterized. The pheromone induction in pws6 mutant cells was specific to nutrient: the M-factor pheromone was induced without nitrogen starvation but not without glucose starvation. This result suggests that the pws6 mutant might have a specific defect in the pathway for nitrogen starvation. The pws6 mutant induces P-factor pheromone as well as M-factor without starvation of nitrogen in temperature sensitive mode, suggesting that the pheromone induction phenotype of pws6 mutation is not cell-type specific. From cloning of the $pws6^+$ gene by complementation of the temperature sensitive growth defect, three plasmids containing 8.1 kb, 3.3 kb, and 4.8 kb yeast DNA were recovered. These plasmids complement the growth defect of the pws6 mutant by 100%, 70%, and 10~20%, respectively. The abilities of these plasmids to complement pheromone induction phenotype of pws6 mutant cells were correlated well with the efficiencies of complementation of the growth defect. With comparison of their open reading frames to the complementation efficiencies, it is concluded that the open reading frame, SPBC19C7.06 is responsible for the complementation of temperature sensitive phenotype of the pws6 mutant. This open reading frame, named prs1, contains one long exon with no intron and encodes a putative prolyl tRNA synthetase. The putative Prs1 protein exhibits significant similarities to the prolyl tRNA synthetases of other species.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.223-227
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• 2010

RNase E plays a major role in the degradation and processing of a large number of RNA transcripts in Escherichia coli and forms the core component of the degradosome, a large protein complex involved in RNA metabolism. RraA and RraB are recently discovered protein inhibitors of RNase E and are evolutionarily conserved. In this study, we observed that, unlike RraA, overexpression of RraB did not rescue growth arrest of E. coli cells overexpressing RNase E. To examine whether this phenomenon stems from differential inhibitory effects of RraA and RraB on RNase E substrates, we analyzed three in vivo RNase E substrates. The results showed that RraA inhibited RNase E activity more efficiently than RraB on the degradation of RNA I, which controls the copy number of ColE1-type plasmid, and rpsO mRNA encoding ribosomal protein S15, while RraB was unable to inhibit the processing of pM1 RNA, a precursor of the RNA component of RNase P, by RNase E. Our results imply that RraB inhibits RNase E activity in a more substrate-dependent manner than RraA and this property of RraB may explain why overexpression of RraB could not rescue cells overexpressing RNase E from growth arrest.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.286-288
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• 2005

MicroRNA (miRNA)는 작은 크기의 RNA분자로서 동식물의 유전자 발현 과점을 직접적으로 조절하는 인자로 알려져 있다. MiRNA는 보통 목표 유전자의 3'-UTR 영역에 상보성을 갖고 결합함으로써 작용하며 특히 miRNA의 5'부분의 8 nt 정도가 seed로서 중요하다고 알려져 있다. 반면 최근의 연구에 따르면 seed 부분의 서열의 조성 및 양상이 변화함에 따라 특이도가 결정됨을 알 수 있지만 기존의 컴퓨터를 이용한 miRNA 목표 유전자 예측 방법들은 이러한 정보를 활용하지 못한다. 본 논문에서는 열역학적인 수치와 서열의 조성뿐 아니라 miRNA:mRNA pair의 위치에 기반한 정보들을 학습에 자질로서 포함하여 목표 유전자를 예측한다. 그 결과는 위치 기반 자질이 학습 성능 향상에 중요하게 기여함을 보여준다.

• Korean Journal of Microbiology
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• v.31 no.3
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• pp.184-188
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• 1993

Novel Ustilagomaydis strains, designated as SH1 to 14 containing new types of ds RNA segments, are identified from corn smut in Korea. Among 14 isolates, 7 isolates appear to posses virus particles and the other isolates may contain dsRNA as a plasmid form. The pattern of dsRNA is highly diverse form a typical P-type containing one or more of H, M, and L dsRNAs to the one containing one or move M dsRNAs. It is likely that the strains containing H dsRNA posses virus particles which were confirmed by sucrose density gradient followed with different range of specificity and the activity of the strain (SH14) is stronger than A4 toxin. The sensitivity of 14 isolates is also very diverse and two strains (SH10, SH11) appear tobe universal sensitve strains against 5 tested toxin samples.

• Korean Journal of Agricultural Science
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• v.34 no.1
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• pp.47-52
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• 2007

유전자의 발현이 다양한 형태로 억제되는 것을 silencing이라고 한다. 유전자 발현억제 방법 중 antisense RNA는 자연 상태의 mRNA에 역상보적인 RNA 분자로서 형질전환된 세포에서 그 mRNA의 전이을 억제하는 데 이용된다. RNA분자에 대하여 상보적 염기배열을 갖는 RNA는 분자간 결합을 연결하여 RNA의 기능 발현에 억제적으로 작용한다고 생각된다. 미생물에 나타나는 유전자발현 제어기작으로서 어느 특정한 mRNA에 대하여 상보적인 RNA가 유전자 발현의 억제인자로서 작용하고 있는 예가 몇 가지 알려져 있다. 이러한 경우 antisense RNA는 mRNA 상의 전이개시영역과 상보적 배열을 하고 있고, 전이과정을 방해한다고 추정되고 있지만 작용기작의 상세한 내용은 아직 명확하지가 않다. 한편 안티센스RNA는 임의의 표적유전자에 대하여 인위적으로 제작할 수가 있기 때문에 인위적인 유전자발현제어의 한 방법으로 이용되고 있다. 특정한 유전자에 대한 antisense RNA를, 발현하는 유전자를 인위적으로 제작하여 세포내에 도입하면 표적유전자의 발현을 특이적으로 억제 제어할 수 있는 것이 기대되어, 다양한 생물체를 대상으로 하여 많은 시도가 이루어지고 있으며 몇 가지 성공적인 보고가 있다. 그 중 식물이차대사과정에 관련 유전자를 대상으로 antisense RNA 기법으로 유전자의 발현억제와 이차대사산물 생산조절에 관한 연구를 이 논문에서 조사하고 정리하였다.