• 미생물학회지
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• 제28권1호
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• pp.55-64
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• 1990

원형질체 융합을 통하여 killer 효모의 유전형질을 기존의 ethanol 발효효묘에 도입하므로서 야생의 killer 효모에 저항성을 가지고, 오염효모를 치사시킬 수 있으며, ethanol 발효능도 유지하는 새로운 효모균주를 개발하였다. 먼저 융합주의 생리적인 특성을 검토한 바, 융합주는 양천주에 비하여 세 적이 크고, DNA 함량이 높았으며, 증식도는 친주와 유사한 경향이었다. 또 융합주를 최소배지에서 보존하는 것이 안정성을 높이는 방법이었고, 7일 간격으로 7회 계대배양하므로서 유전적으로 안정화시킨 융합주를 6개월 간 계속 사용한 결과 segregant가 전혀 나타나지 않았으므로 매우 안정하였다. 또한 융합주는 핵 및 포자를 형성함을 관찰 할 수 있었고, TTC 정색반응에서 적색 및 pink 색을 띄었으며, 탄소원의 자화성 및 발효능은 천주와 유사하였는데, KCI, NaCl, sodium propionate alc cycloheximide 등에 대한 내성도 양친주의 한쪽을 따랐다. 그리고, 융합주를 20% glucose와 sucrose에서 72시간 및 60시간 배양했을 때, FWKS 260의 경우 각각 9.6v/v% 및 9.8v/v%의 ethanol을 생성하였고, 감수성주와 혼합배양한 결과 FWKS260의 경우 48시간 이후에는 감수성주를 거의 발견할 수 없었으며, 전주 및 융합주의 dsRNA plasmid를 추출하여 전기 2.5kb의 L 및 M dsRNA plasmidsms는 서로 연관성이 있으며, killer toxin 분비 및 저항성을 나타내는 유전자를 지배하는 것은 M dsRNA plasmid임을 확인할 수 있었다. 수 있었다.

• Molecules and Cells
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• 제45권7호
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• pp.435-443
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• 2022

In response to environmental changes, signaling pathways rewire gene expression programs through transcription factors. Epigenetic modification of the transcribed RNA can be another layer of gene expression regulation. N⁶-adenosine methylation (m⁶A) is one of the most common modifications on mRNA. It is a reversible chemical mark catalyzed by the enzymes that deposit and remove methyl groups. m⁶A recruits effector proteins that determine the fate of mRNAs through changes in splicing, cellular localization, stability, and translation efficiency. Emerging evidence shows that key signal transduction pathways including TGFβ (transforming growth factor-β), ERK (extracellular signal-regulated kinase), and mTORC1 (mechanistic target of rapamycin complex 1) regulate downstream gene expression through m⁶A processing. Conversely, m⁶A can modulate the activity of signal transduction networks via m⁶A modification of signaling pathway genes or by acting as a ligand for receptors. In this review, we discuss the current understanding of the crosstalk between m⁶A and signaling pathways and its implication for biological systems.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.253-253
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• 2006

DNA has not been played the role as a biocatalyst in evolutionary history, although RNA and protein function as a biocatalyst. DNA double helix structure is believed to be impossible to form intricate active enzymatic sites. In addition, the chemical stability of DNA prevents the ability from self-modifying reactions. However, recent development of DNA engineering enables to create artificial enzymatic ability of DNA (deoxyribozyme) such as RNA cleavage and DNA modification. We investigated optimal conditions for enzymatic activity of DNA-Pt complex, and compared it with that of horse radish peroxidase. We report here that base sequence of DNA, pH and temperature affect the enzymatic activity of DNA-Pt complex.

• 약학회지
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• 제49권3호
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• pp.205-211
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• 2005

The 3' UTR (3' untranslated region) plays important roles in controlling gene expression through regulating 3' polyadenylation, mRNA export, subcellular localization, translational efficiency, and mRNA stability. Changes in the 3' UTR sequence in an expressed transcript can result in functional changes of the genes that are expressed in pathological conditions compared with those genes expressed in normal physiologic conditions. A genome-wide survey of 3' UTR variation was performed for the genes expressed during hematopoietic differentiation from CD34+ stem/progenitor cells to CD 15 + myeloid progenitor cells. Wide-spread differential usage of the 3' UTR was observed from the genes expressed during this cellular transition. This study implies that the 3' UTR can be a highly coordinated region for post-transcriptional regulation of the function of expressed genes.

• KSBB Journal
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• 제25권6호
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• pp.513-519
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• 2010

Marine bacterium producing pigment was isolated from the solar saltern of Mijo-myeon, Namhae, Korea. Based on phenotypic characteristics and 16S rRNA sequence analysis, the strain was identified as Kocuria sp., which produced a yellow pigment. The pigment showed UV absorption maximum at 469nm. The bacterial strain grew well on Marine broth 2216 culture medium. Productivity of the pigment reached the maximum value after 44 hours at $30^{\circ}C$, 2% NaCl and pH 6.0. The pigment was produced best when supplied by 1% lactose as a carbon source and 1% beef extract as a nitrogen source. The result of the color stability study showed that pigment extracted from the strain by ethanol was stable at $-20-25^{\circ}C$ and also showed higher stability over 70% for 14 days in light conditions at $25^{\circ}C$. The pigment extract was also stable for all metal ions tested, except for $FeCl_2$.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.20-20
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• 2017

Plant genomes include heterochromatic loci that consist of repetitive sequences and transposable elements. LTR retrotransposon is the major class of transposons in advanced plants in terms of proportion in plant genome. The elements contribute not only to genome size but also to genome stability and gene expression. A number of cases have been reported transposon insertions near genic regions affect crop traits such as fruit pigments, stress tolerance, and yields. Functional LTR retrotransposons produce extrachromosomal DNA from genomic RNA by reverse transcription that takes place within virus-like-particles (VLPs). DECREASED DNA METHYLATION 1 (DDM1) plays important roles in maintaining DNA methylation of heterochromatin affecting all sequence contexts, CG, CHG, and CHH. Previous studies showed that ddm1 mutant exhibits massive transcription of retrotransposons in Arabidopsis, but only few of them were able to create new insertions into the genome. RNA-dependent RNA POLYMERASE 6 (RDR6) is known to function in restricting accumulation of transposon RNA by processing the transcripts into 21-22 nt epigenetically activated small interfering RNA (easiRNA). We purified VLPs and sequence cDNA to identify functional LTR retrotransposons in Arabidopsis ddm1 and ddm1rdr6 plants. Over 20 LTR copia and gypsy families were detected in ddm1 and ddm1rdr6 sequencing libraries and most of them were not reported for mobility. In ddm1rdr6, short fragments of ATHILA gypsy elements were detected. It suggests easiRNAs might regulate reverse transcription steps. The highest enriched element among transposon loci was previously characterized EVADE element. It has been reported that active EVADE element is more efficiently silenced through female germline than male germline. By genetic analyses, we found ddm1 and rdr6 mutation affect maternal silencing of active EVADE elements. DDM1-GFP protein accumulated in megaspore mother cell but was not found in mature egg cell. The fusion protein was also found in early embryo and maternal DDM1-GFP allele was more dominantly expressed in the embryo. We observed localization of DDM1-GFP in Arabidopsis and DDM1-YFP in maize and found the proteins accumulated in dividing zone of root tips. Currently we are looking at cell cycle dependency of DDM1 expression using maize system. Among 10 AGO proteins in Arabidopsis, AGO9 is specifically expressed in egg cell and shoot meristematic cells. In addition, mutation of AGO9 and RDR6 caused failure in maternal silencing, implying 21-22 nt easiRNA pathway is important for retrotransposon silencing in female gametophyte or/and early embryo. On the other hand, canonical 24 nt sRNA-directed DNA methylation (RdDM) pathways did not contribute to maternal silencing as confirmed by this study. Heat-activated LTR retrotransposon, ONSEN, was not silenced by DDM1 but the silencing mechanisms require RdDM pathways in somatic cells. We will propose distinct mechanisms of LTR retrotransposons in germline and somatic stages.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.97-97
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• 2017

Plant genomes include heterochromatic loci that consist of repetitive sequences and transposable elements. LTR retrotransposon is the major class of transposons in advanced plants in terms of proportion in plant genome. The elements contribute not only to genome size but also to genome stability and gene expression. A number of cases have been reported transposon insertions near genic regions affect crop traits such as fruit pigments, stress tolerance, and yields. Functional LTR retrotransposons produce extrachromosomal DNA from genomic RNA by reverse transcription that takes place within virus-like-particles (VLPs). DECREASED DNA METHYLATION 1 (DDM1) plays important roles in maintaining DNA methylation of heterochromatin affecting all sequence contexts, CG, CHG, and CHH. Previous studies showed that ddm1 mutant exhibits massive transcription of retrotransposons in Arabidopsis, but only few of them were able to create new insertions into the genome. RNA-dependent RNA POLYMERASE 6 (RDR6) is known to function in restricting accumulation of transposon RNA by processing the transcripts into 21-22 nt epigenetically activated small interfering RNA (easiRNA). We purified VLPs and sequence cDNA to identify functional LTR retrotransposons in Arabidopsis ddm1 and ddm1rdr6 plants. Over 20 LTR copia and gypsy families were detected in ddm1 and ddm1rdr6 sequencing libraries and most of them were not reported for mobility. In ddm1rdr6, short fragments of ATHILA gypsy elements were detected. It suggests easiRNAs might regulate reverse transcription steps. The highest enriched element among transposon loci was previously characterized EVADE element. It has been reported that active EVADE element is more efficiently silenced through female germline than male germline. By genetic analyses, we found ddm1 and rdr6 mutation affect maternal silencing of active EVADE elements. DDM1-GFP protein accumulated in megaspore mother cell but was not found in mature egg cell. The fusion protein was also found in early embryo and maternal DDM1-GFP allele was more dominantly expressed in the embryo. We observed localization of DDM1-GFP in Arabidopsis and DDM1-YFP in maize and found the proteins accumulated in dividing zone of root tips. Currently we are looking at cell cycle dependency of DDM1 expression using maize system. Among 10 AGO proteins in Arabidopsis, AGO9 is specifically expressed in egg cell and shoot meristematic cells. In addition, mutation of AGO9 and RDR6 caused failure in maternal silencing, implying 21-22 nt easiRNA pathway is important for retrotransposon silencing in female gametophyte or/and early embryo. On the other hand, canonical 24 nt sRNA-directed DNA methylation (RdDM) pathways did not contribute to maternal silencing as confirmed by this study. Heat-activated LTR retrotransposon, ONSEN, was not silenced by DDM1 but the silencing mechanisms require RdDM pathways in somatic cells. We will propose distinct mechanisms of LTR retrotransposons in germline and somatic stages.

• Biomolecules & Therapeutics
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• 제20권1호
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• pp.43-49
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• 2012

Stimulation of mast cells through the high affinity IgE receptor (Fc${\varepsilon}$RI) induces degranulation, lipid mediator release, and cytokine secretion leading to allergic reactions. Although various signaling pathways have been characterized to be involved in the Fc${\varepsilon}$RI-mediated responses, little is known about the precious mechanism for the expression of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in mast cells. Here, we report that rapamycin, a specific inhibitor of mammalian target of rapamycin (mTOR), reduces the expression of TNF-${\alpha}$ in rat basophilic leukemia (RBL-2H3) cells. IgE or specific antigen stimulation of RBL-2H3 cells increases the expression of TNF-${\alpha}$ and activates various signaling molecules including S6K1, Akt and p38 MAPK. Rapamycin specifically inhibits antigeninduced TNF-${\alpha}$ mRNA level, while other kinase inhibitors have no effect on TNF-${\alpha}$ mRNA level. These data indicate that mTOR signaling pathway is the main regulation mechanism for antigen-induced TNF-${\alpha}$ expression. TNF-${\alpha}$ mRNA stability analysis using reporter construct containing TNF-${\alpha}$ adenylate/uridylate-rich elements (AREs) shows that rapamycin destabilizes TNF-${\alpha}$ mRNA via regulating the AU-rich element of TNF-${\alpha}$ mRNA. The antigen-induced activation of S6K1 is inhibited by specific kinase inhibitors including mTOR, PI3K, PKC and $Ca^{2+}$chelator inhibitor, while TNF-${\alpha}$ mRNA level is reduced only by rapamycin treatment. These data suggest that the effects of rapamycin on the expression of TNF-${\alpha}$ mRNA are not mediated by S6K1 but regulated by mTOR. Taken together, our results reveal that mTOR signaling pathway is a novel regulation mechanism for antigen-induced TNF-${\alpha}$ expression in RBL-2H3 cells.

• 생명과학회지
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• 제30권11호
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• pp.947-955
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• 2020

구제역바이러스(FMDV)는 피코나바이러스 과에 속하는 바이러스로서 야생과 가축화된 소와 돼지에 감염된다. FMDV는 제어되기 어려워서 가축의 생산과 국제통상에 큰 장애가 되고 있다. FMDV RNA 게놈의 복제 과정에서 3D 중합효소가 특이적인 복제 기능을 담당하는데 게놈에 결합하는 부위가 매우 중요하다. 이 사실은 FMDV 게놈의 비코딩영역 내에서 3D 중합효소에 의해 인지되는 특이 RNA 구조가 관여함을 제시한다. 이 과정에서 cis-acting replication element (CRE)는 RNA 복제를 위한 개시에 필요하다. FMDV CRE는 15-17 뉴클레오티드의 고리와 이를 지지하는 이중가닥으로 형성된 줄기-고리 모양을 가지며 이들을 구성하는 RNA 뉴클레오티드 서열의 차이가 다른 RNA 이차구조를 생성한다. CRE 이외에 FMDV 복제를 위해서 많은 바이러스와 세포 인자들이 단백질-단백질 결합과 단백질-RNA 결합을 통해 협조적인 네트워크를 만들어낸다. 이 연구에서 국내에서 2010년부터 2017년 까지 구제역이 발생한 소와 돼지에서 FMDV를 분리하여 CRE 서열을 분석하였으며 이들 FMDV들은 A형과 O형의 유전자형을 가졌다. 흥미롭게 국내 FMDV들의 CRE RNA 이차구조의 변이들은 바이러스 간의 계통유전학적 상관관련성과 일치하며 특정 숙주 동물종의 FMDV 감염의 특이성을 밝혀주었다. 이를 토대로 국내 FMDV의 각 유전군의 분류는 독특한 기능적 CRE에 의해 특징지을 수 있으며 새로운 유전적 계통의 진화학적 연속성은 특징있는 CRE 모티프의 구분과 연관지을 수 있다. 그러므로 CRE의 특이적 RNA 구조는 숙주 동물종 의존적인 FMDV 부류의 부가적인 단서로 활용할 수 있음을 제안한다. 이들 연구 결과들은 향후 FMDV 대량감염이 발생할 때 숙주동물종의 특이성을 CRE 서열로 조기에 정확히 분석하는데 도움이 될 것이다.

• 한국발생생물학회지:발생과생식
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• 제17권3호
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• pp.275-287
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• 2013

Although, one of the etiologies of localized lipodystrophy of the subcutaneous connective tissue (cellulite) is the histological alternation of adipose tissue, the characteristics of expression of the components of extracellular matrix (ECM) components during adipogenesis are not uncovered. In this study, the effects of caffeine and Ishige okamurae originated diphlorethohydroxycarmalol (DPHC) on the expression of extracellualr fibers was analyzed with quantitative RT-PCR during differentiation induction of mouse subcutaneous adipose derived stem cells (msADSC) into adipocyte. The expression levels of Col1a, Col3a1, and Col61a were decreased by the adipogenci induction in a time-dependent manners. However, Col2a mRNA and Col4a1 mRNA expressions were oposit to them. Caffeine and DPHC stimulated the changes of the expression of these collagens. Eln mRNA expression was increased by induction. DPHC stimulated the expression of it. Mfap5 mRNA expression was deceased in both adipogenic cell and matured adipocytes. Caffeine suppressed the expression of Mfap5 but the effect of DPHC was different by the concentration. The expression of bioglycan, decorin, and lumican were also modified by caffeine and DPHC in a concentration-dependent manner. Based on this study, we revealed firstly the effects of caffeine and DPHC on the expression of collagens, elastin, and glycoproteins during adipogenesis of msADSCs. Those results suggest that DPHC may have antiadipogenic effect and has more positive effets on normal adipose tissue generation and work as suppressor the abnormality of ECM structure. Such results indicate that DPHC can be applied in keeping the stability of the ECM of adipogenic tissues.