• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2153-2158
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• 2014

Beclin 1 is a key factor for initiation and regulation of autophagy, which is a cellular catabolic process involved in tumorigenesis. To investigate the role of alternative splicing of Beclin1 in the regulation of autophagy in leukemia cells, Beclin1 mRNA from 6 different types of cell lines and peripheral blood mononuclear cells from 2 healthy volunteers was reversely transcribed, subcloned, and screened for alternative splicing. New transcript variants were analyzed by DNA sequencing. A transcript variant of Beclin 1 gene carrying a deletion of exon 11, which encoded a C-terminal truncation of Beclin 1 isoform, was found. The alternative isoform was assessed by bioinformatics, immunoblotting and subcellular localization. The results showed that this variable transcript is generated by alternative 3' splicing, and its translational product displayed a reduced activity in induction of autophagy by starvation, indicating that the spliced isoform might function as a dominant negative modulator of autophagy. Our findings suggest that the alternative splicing of Beclin 1 might play important roles in leukemogenesis regulated by autophagy.

• Journal of Microbiology and Biotechnology
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• 제23권5호
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• pp.637-643
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• 2013

We have demonstrated that 1-deoxynojirimycin (DNJ) isolated from Bacillus subtilis MORI could enhance the levels of adiponectin and its receptors in differentiated 3T3-L1 adipocytes, which has been shown to be effective in lowering blood glucose levels and enhancing insulin sensitivity. DNJ was not toxic to differentiated 3T3-L1 adipocytes for up to a concentration of $5{\mu}M$. In terms of expression levels of adiponectin and its receptors (AdipoR1 and AdipoR2), DNJ in concentrations as low as $0.5{\mu}M$ elevated both mRNA and protein levels of adiponectin and transcript levels of AdipoR1 and AdipoR2. In addition, DNJ increased phosphorylation of 5' adenosine monophosphate-activated protein kinase (AMPK) in a statistically significant manner. Finally, treatment with DNJ resulted in increased mRNA expression of glucose transporter 4 (GLUT4), which encodes for a glucose transporter, along with a significant increase in glucose uptake into the adipocytes based on results of a 2-deoxy-D-[$^3H$] glucose uptake assay. Our findings indicate that DNJ may greatly facilitate glucose uptake into adipose tissues by increasing the action of adiponectin via its up-regulated expression as well as its receptor genes. In addition, the glucose-lowering effects of DNJ may be achieved by an increased abundance of GLUT4 protein in the plasma membrane, as a consequence of the increased transcript levels of the GLUT4 gene and the activation of AMPK.

• 생명과학회지
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• 제25권10호
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• pp.1098-1102
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• 2015

본 연구에서는 C2C12 근육 세포의 분화 과정에 있어 IGF-I이 지방산의 수송을 담당하는 FABPpm mRNA 및 단백질 발현에 어떠한 영향을 미치는지에 대해 알아보았다. 그 결과 근육세포의 분화에 있어 FABPpm의 단백질과 mRNA 발현이 IGF-I에 의해 유의하게 조절되었음을 알 수 있었다. 이는 기존의 여러 연구의 결과인 IGF-I이 골격근에서 근육 관련 유전자들의 발현을 조절하여 근부피 유지 및 증대에 중심적인 역할 것뿐만 아니라, 지방산의 수송을 담당하는 FABPpm의 발현에도 영향을 미친다는 사실을 밝혔다는 것에 의의가 있다고 생각된다. 향후 골격근에서 IGF-I에 의한 FABPpm 발현 조절에 있어, 세포 내부에서의 신호전달 경로 및 상호작용 인자들에 관한 연구를 통해 지방 대사를 조절하는 기전에 관한 연구가 필요할 것으로 사료된다.

• 생명과학회지
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• 제24권12호
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• pp.1284-1290
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• 2014

본 연구에서는 C2C12 근육 세포에서 IGF-I이 지방산 저장과 사용에 영향을 미치는 FATP1의 mRNA 및 단백질 발현에 미치는 영향에 대해 알아보았다. 그 결과 IGF-I이 FATP1의 단백질과 mRNA 발현을 유의성 있게 조절하였음을 알 수 있었다. 이는 골격근에서 IGF-I이 근육 관련 유전자들의 발현을 조절하여 근부피 유지 및 증대에 중심적인 역할을 한다는 기존의 연구 패턴들에서 벗어나, IGF-I이 골격근 세포의 분화에 있어 지방산의 수송을 담당하는 FATP1의 발현에도 영향을 미친다는 사실을 증명하였다는데 의의가 있다고 사료된다. 향후 IGF-I에 의한 FATP1의 지방산 저장의 수준과 산화 과정에 있어 상호작용하는 기타 매개체들과의 관계에 대한 연구가 필요할 것으로 사료된다.

• 생명과학회지
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• 제21권3호
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• pp.368-374
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• 2011

식물의 저온 적응 메카니즘에서 아스코브산과 관련된 효소 중 MDHA 환원효소의 활성도와 과산화수소, 아스코브산의 함량, mRNA의 발현수준과의 연관성을 연구한 결과는 다음과 같다. MDHA 환원효소의 활성도 변화는 저온에 노출되는 시간이 길어질수록 증가하였으며 6시간 이후에 엽록체분획과 세포질분획에서 급격하게 증가하는 경향을 보였으나 실온으로 회복시켰을 때 효소의 활성도가 상대적으로 감소하는 경향을 보였다. 저온에 노출된 동안 아스코브산의 함량은 비교적 일정한 경향을 보이다가 실온으로 회복시키면 그 이후에는 급격하게 증가하는 경향을 보였다. 반면 저온에 노출되는 동안 급격히 dehydroascorbate 함량이 감소하였다가 실온으로 회복되면 약간 증가하는 경향을 보였다. 아스코브산의 함량과 엽록체분획과 세포질분획의 MDHA 환원효소의 활성도와의 상관관계는 각각 정의 상관($R^2$=0.9240, 0.9108)을 나타내었으나 디하이드로아스코브산의 함량과 MDHA 환원효소의 활성도 사이에는 각각 부의 상관($R^2$=0.8638, 0.8980)을 나타내었다. MDHA 환원효소 활성도와 과산화수소의 함량과의 상관관계를 과산화수소의 생성량이 증가하면 MDHA 환원효소의 활성도가 증가하는 정의 상관($R^2$=0.9443, 0.9647)을 나타내었다. 저온스트레스 처리 시간이 증가할수록 MDHA 환원효소의 mRNA의 발현 수준과 총 MDHA 환원효소의 활성도가 증가하는 경향을 나타내었다.

• Journal of Microbiology
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• 제38권3호
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• pp.145-149
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• 2000

GroEL is a typical molecular chaperone. GroEL synthesis patterns at various culture temperatures in Escherichia coli were investigated in this study. No significant differences in the amount of GroEL produced from the chromosome were found at 30 and 37$^{\circ}C$. However, GroEL production increased 3.4-fold at 42$^{\circ}C$. GroEL synthesis was not transient but continuous at 42$^{\circ}C$, although most heat shock gene expression is known to be transient. To understand the role of the groEL structural gene, a groE promoter-lacZ fusion was constructed. Interestingly , while transcriptional fusion is not thermally inducible, it is inducible by ethanol, suggesting that the secondary structure of the groEL transcript is involved in thermal regulation of the groEL gene. Secondary structures of groE mRNA at 37 and 42$^{\circ}C$ were compared using the computer program RNAdraw. Distinct structures at the two temperatures were found, and these structures may be related to a high level of GroEL expression at 42$^{\circ}C$.

• ALGAE
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• 제26권3호
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• pp.229-235
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• 2011

Spliced leader (SL) trans-splicing is a mRNA processing mechanism in dinoflagellate nuclear genes. Although studies have identified a short, conserved dinoflagellate SL (dinoSL) sequence (22-nt) in their nuclear-encoded transcripts, whether the majority of nuclear-coded transcripts in dinoflagellates have the dinoSL sequence remains doubtful. In this study, we investigated dinoSL-containing gene transcripts using 454 pyrosequencing data (Cochlodinium polykrikoides, 93 K sequence reads, 31 Mb; Prorocentrum minimum, 773 K sequence reads, 291 Mb). After making comparisons and performing local BLAST searches, we identified dinoSL for one C. polykrikoides gene transcript and eight P. minimum gene transcripts. This showed transcripts containing the dinoSL sequence were markedly fewer in number than the total expressed sequence tag (EST) transcripts. In addition, we found no direct evidence to prove that most dinoflagellate nuclear-coded transcripts have this dinoSL sequence.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.313.3-314
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• 2002

Cyclooxygenase-2 (COX-2) is an inducible enzyme expressed in response to a variety of cytokines and other proinflammatory stimuli. It has been known that aberrant up-regulation of COX-2 is associated with resistance to apoptosis. Contrary to the above notion. treatment of MCF10A-ras cells with the anti-tumor agent ET -18-O-$CH_3$ caused increased expression of COX-2 and its mRNA transcript. while inducing apoptosis as revealed by proteolytic cleavage of poly(ADP-ribose)polymerase. caspase-3 activation, and positive TUNEL staining. (omitted)

• 한국환경성돌연변이발암원학회지
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• 제19권1호
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• pp.28-33
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• 1999

The SNF2 family includes proteins from a variety of species with roles I cellular processes such as transcriptional regulation, recombination and various types of DNA repair. Several proteins with unknown function are also included in this family. Here, we report the cloning and characterization of hrp 2+ gene (helicase related gene from S. pombe) which was isolated by PCR amplication using the conserved domain of SNF2 motifs within the ERCC6 gene which encodes a protein involved in DNA excision repair. The hrp2+ gene was isolated by screening with yeast S. pombe genomic library. The isolated cloned contained 6.5 kb insert DNA. Southern blot analysis confirmed that S. pombe chromosome contains the same DNA as hrp2+ gene and this gene exists as a single copy in S. pombe genome. The 4.7 kb transcript of mRNA was identified by Northern blot. To examined the transcriptional regulation of hrp2+ gene, DNA damaging agents were treated. These results indicated that the hrp2+ gene may not be directly involved in DNA replication, but may be involved in damage response pathway.

• BMB Reports
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• 제37권5호
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• pp.565-573
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• 2004

Orexin-A and orexin-B (hypocretin-1 and hypocretin-2, respectively) are important hypothalamic neuro-peptides, which are encoded by a single mRNA transcript and stimulate food intake as well as regulate wakefulness. Here we determined the solution structure of orexin-A by NMR spectroscopy and by simulated-annealing calculation. The structural features of orexin-A involve two $\alpha$-helices, with the hydrophobic residues disposed to on one side of helix, and hydrophilic residues to the other. A hydrophilic turn induced by two disulfide bonds provides the key difference between orexin-A and -B. With previous mutagenic studies, the derived structure of orexin-A provides us with a structure-functional view for novel drug design.