• Journal of Microbiology
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• 제44권2호
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• pp.217-225
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• 2006

Kaposi's sarcoma-associated herpesvirus (KSHV) RTA transcription factor is recruited to its responsive elements through interaction with RBP-Jk that is a downstream transcription factor of the Notch signaling pathway that is important in development and cell fate determination. This suggests that KSHV RTA mimics cellular Notch signal transduction to activate viral lytic gene expression. Here, I demonstrated that unlike other B lymphoma cells, KSHV -infected primary effusion lymphoma BCBL1 cells displayed the constitutive activation of ligand-mediated Notch signal transduction, evidenced by the Jagged ligand expression and the complete proteolytic process of Notch receptor I. In order to investigate the effect of Notch signal transduction on KSHV gene expression, human Notch intracellular (hNIC) domain that constitutively activates RBP-Jk transcription factor activity was expressed in BCBL1 cells, TRExBCBL1-hNIC, in a tetracycline inducible manner. Gene expression profiling showed that like RTA, hNIC robustly induced expression of a number of viral genes including KS immune modulatory gene resulting in downregulation of MHC I and CD54 surface expression. Finally, the genetic analysis of KSHV genome demonstrated that the hNIC-mediated expression of KS during viral latency consequently conferred the downregulation of MHC I and CD54 surface expression. These results indicate that cellular. Notch signal transduction provides a novel expression profiling of KSHV immune deregulatory gene that consequently confers the escape of host immune surveillance during viral latency.

• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.9791-9795
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• 2014

To study the gene expression change and possible signal pathway during androgen-dependent prostate cancer (ADPC) becoming androgen-independent prostate cancer (AIPC), an LNCaP cell model of AIPC was established using flutamide in combination with androgen-free environment inducement, and differential expression genes were screened by microarray. Then the biological process, molecular function and KEGG pathway of differential expression genes are analyzed by Molecule Annotation System (MAS). By comparison of 12,207 expression genes, 347 expression genes were acquired, of which 156 were up-ragulated and 191 down-regulated. After analyzing the biological process and molecule function of differential expression genes, these genes are found to play crucial roles in cell proliferation, differntiation, cell cycle control, protein metabolism and modification and other biological process, serve as signal molecules, enzymes, peptide hormones, cytokines, cytoskeletal proteins and adhesion molecules. The analysis of KEGG show that the relevant genes of AIPC transformation participate in glutathione metabolism, cell cycle, P53 signal pathway, cytochrome P450 metabolism, Hedgehog signal pathway, MAPK signal pathway, adipocytokines signal pathway, PPAR signal pathway, TGF-${\beta}$ signal pathway and JAK-STAT signal pathway. In conclusion, during the process of ADPC becoming AIPC, it is not only one specific gene or pathway, but multiple genes and pathways that change. The findings above lay the foundation for study of AIPC mechanism and development of AIPC targeting drugs.

• Journal of Microbiology and Biotechnology
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• 제30권2호
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• pp.196-205
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• 2020

In this study, the acidic lipase from Aspergillus niger (ANL) was homologously expressed in A. niger. The expression of ANL was significantly improved by the expression of the native ANL with the introns, the addition of the Kozak sequence and the optimization of the signal sequences. When the cDNA sequence of ANL fused with the glaA signal was expressed under the gpdA promoter in A. niger, no lipase activity could be detected. We then tried to improve the expression by using the full-length ANL gene containing three introns, and the lipase activity in the supernatant reached 75.80 U/ml, probably as a result of a more stable mRNA structure. The expression was further improved to 100.60 U/ml by introducing a Kozak sequence around the start codon due to a higher translation efficiency. Finally, the effects of three signal sequences including the cbhI signal, the ANL signal and the glaA signal on the lipase expression were evaluated. The transformant with the cbhI signal showed the highest lipase activity (314.67 U/ml), which was 1.90-fold and 3.13-fold higher than those with the ANL signal and the glaA signal, respectively. The acidic lipase was characterized and its highest activity was detected at pH 3.0 and a temperature of 45℃. These results provided promising strategies for the production of the acidic lipase from A. niger.

• 한국전자통신학회논문지
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• 제8권8호
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• pp.1235-1240
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• 2013

본 논문에서는 색분산이 최적으로 보상된 광통신 시스템에서 자기위상변조와 색분산으로 인해 열화되는 신호의 아이페널티에 대해 근사적인 수학식을 유도하였다. 이러한 분석 연구를 통해 최적으로 색분산 보상된 광통신 시스템에서 신호의 왜곡에 대한 근사식을 얻을 수 있다. 우리는 이 근사식의 효용성을 보이기 위해서 이전 연구의 시뮬레이션 결과와 근사식의 결과를 비교하는 결과를 보인다. 본 논문의 결과를 이용하면 복잡한 비선형 시뮬레이션을 통해 얻을 수 있는 광신호의 왜곡에 대해 손쉽게 그 결과를 예측할 수 있으며, 각종 시스템 파라미터가 시스템에 미치는 영향도 쉽게 파악할 수 있다.

• 한국미생물·생명공학회지
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• 제26권1호
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• pp.68-75
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• 1998

A. niger의 GOD(Glucose Oxidase) 대량생산과 효율적인 분비를 protein의 대량생산에 많이 사용되는 strain인 S. cerevisiae에서 시도하였다. S. cerevisiae의 ADH1과 GAL 10 promotor, 그리고 ${alpha}$-MF signal sequence와 A. oryzae의 ${alpha}$-amylase signal sequence 및 S. cerevisiae의 GAL7과 A. niger의 GOD terminator를 이용하여 4개의 expression vector를 합성한 후 S. cerevisiae 2805에 auxotroph 방법으로 형질변환시켰다. 변이체들을 배양하여 세포내와 세포외의 GOD활성도를 분석한 결과 GAL 10 promotor가 삽입된 pGAL변이체들이 ADH1 promotor가 삽입된 pADH 변이체들 보다 GOD 생산성이 높았다. GAL 10 promotor와 A. oryzae의 ${alpha}$-amylase signal sequence가 삽입된 pGALGO2에서 115시간 배양시 GOD의 생산이 가장 높았다($GOD_{total}$: 10.3 unit/mL, $GOD_{ex}$: 8.7 unit/mL). 이 수치는 같은 promotor인 GAL 10 promotor와 ${alpha}$-MF signal sequence가 삽입된 pGALGO1보다 3배정도 높다. 이 결과는 ADH 1 promotor를 사용하였을 경우에도 일치하였다. 또한 A. oryzae의 ${alpha}$-amylase signal sequence가 S. cerevisiae의 ${alpha}$-MF signal sequence보다 GOD를 더 효과적으로 분비시켰다. 상기 결과로 미루어 보면 signal sequence가 단백질의 분비 외에도 단백질 합성에도 많은 영향을 주는 것으로 추측된다. pGALGO1과 pGALGO2의 GOD분비효율은 각각 89%, 84%이었다. S. cerevisiae에서는 일반적으로 과당화가 일어나기 때문에 S. cerevisiae에서 합성된 재조합 GOD의 분자량은 250 kDa으로 A. niger의 GOD(170 kDa)보다 더 컸다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.715-717
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• 2014

최근 LTE-A (Long Term Evolution-Advanced)와 같은 무선 통신시스템에서는 멀티미디어 대용량 데이터를 전송하기 위한 64-ary QAM (Quadrature Amplitude Modulation)과 같은 고차 변조방식을 채택하고 있다. 같은 차수의 변조 방식이라도 신호점의 배치 방법에 따라 오류 성능이 매우 다양하게 나타나므로 다양한 신호점 배치 방법의 오류 성능을 분석하기 위해서는 최적 성능 기준이 되는 최적 신호점의 오류 성능식이 필요하다. 오류 바운드에 근거한 최적 오류 성능을 갖는 신호점 배치 방법은 이미 연구된 바 있으나 이에 대한 정확한 심벌 오류 성능식이 유도된 바는 없다. 본 논문은 최적 신호점 배치를 갖는 64-ary QAM에 대한 정확한 심벌 오류 성능식을 유도한다.

• The Korean Journal of Physiology and Pharmacology
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• 제19권2호
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• pp.89-97
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• 2015

The aim of this study was to investigate the involvement of dopaminergic receptors (DR) in behavioral sensitization, as measured by locomotor activity, and the over-expression of cocaine- and amphetamine-regulated transcript (CART) peptides after repeated administration of cocaine in mice. Repeated administrations of cocaine induced behavioral sensitization and CART over-expression in mice. The levels of striatal CART mRNA were significantly increased on the $3^{rd}$ day. CART peptides were over-expressed on the $5^{th}$ day in the striata of behaviorally sensitized mice. A higher proportion of $CART^+$ cells in the cocaine-treated mice were present in the nucleus accumbens (NAc) shell than in the dorsolateral (DL) part of caudate putamen (CP). The concomitant administration of both $D_1R$ and $D_2R$ antagonists, SCH 23390 ($D_1R$ selective) and raclopride ($D_2R$ selective), blocked cocaine induced-behavioral sensitization, CART over-expression, and cyclic adenosine 5'-monophosphate (cAMP)/ protein kinase A (PKA)/phospho-cAMP response element-binding protein (pCREB) signal pathways. SCH 23390 more predominantly inhibited the locomotor activity, CART over-expression, pCREB and PKA activity than raclopride. Cocaine induced-behavioral sensitization was also attenuated in the both $D_1R$ and $D_2R$ knockout (KO) mice, respectively. CART over-expression and activated cAMP/PKA/pCREB signal pathways were inhibited in the $D_1R$-KO mice, but not in the $D_2R$-KO mice. It is suggested that behavioral sensitization, CART over-expression and activated cAMP/PKA/pCREB signal pathways induced by repeated administration of cocaine could be more predominantly mediated by $D_1R$.

• Molecules and Cells
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• 제26권1호
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• pp.34-40
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• 2008

To express an increased level of recombinant Mefp1 (marine mussel adhesive protein) in soluble form, we constructed expression vectors encoding truncated OmpA signal peptide-Mefp1 fusion proteins. OmpA signal peptide (OmpASP) is the 21 residue peptide fragment of the 23 residue OmpA signal sequence cleavable by signal peptidase I. We successfully produced increased levels of soluble recombinant Mefp1 (rMefp1) with various deletions of OmpASP, and found that the increased expression was caused by the increased pI of the N-terminus of the fusion proteins (${\geq}10.55$). All the OmpA signal peptide segments of 3-21 amino acids in length had the same pI value (10.55). Our results suggest that the pI value of the truncated OmpASP ($OmpASP_{tr}$) play an important role in directional signaling for the fusion protein, but we found no evidence for the presence of a secretion enhancer in OmpASP. For practical applications, we increased the expression of soluble rMefp1 with $OmpASP_{tr}$ peptides as directional signals, and obtained rMefp1 with the native amino terminus (nN-rMefp1) using an $OmpASP_{tr}$ Xa leader sequence that contains the recognition site for Xa protease.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-1
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• pp.60-61
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• 2003

Human Genome Project has recently been completed and the information on nucleotide sequences of our whole genome is now available at the public or commercial data banks. Next goals are to identify the functions of each gene and to elucidate the intracellular signal transduction pathways regulating gene expression. We have established a PCR-based bioassay to search for biologically active compounds that can modulate the expression of genes encoding important proteins. (omitted)

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.213-214
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• 2008

In this paper, we analyze the performance of a cooperative communication wireless network over independent and identically distributed (IID) Nakagami-m fading channels. A simple transmission scheme is considered where the relay is operating in amplify-forward (AF) mode. A closed-form expression for symbol error rate (SER) is obtained using the moment generating function (MGF) of the total signal to noise ratio (SNR) of the transmitted signal with binary phase shift keying (BPSK).