• 제목/요약/키워드: Transcriptional activator

검색결과 134건 처리시간 0.027초

Regulation of Phenol Metabolism in Ralstonia eutropha JMP134

  • Kim Youngjun
    • 한국미생물학회:학술대회논문집
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    • 한국미생물학회 2002년도 추계학술대회
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    • pp.27-30
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    • 2002
  • Ralstonia eutrupha JMP134 is a well-known soil bacterium which can metabolite diverse aromatic compounds and xenobiotics, such as phenol, 2,4-dichlorophenoxy acetic acid (2, 4-D), and trichloroethylene (TCE), etc. Phenol is degraded through chromosomally encoded phenol degradation pathway. Phenol is first metabolized into catechol by a multicomponent phenol hydroxylase, which is further metabolized to TCA cycle intermediates via a meta-cleavage pathway. The nucleotide sequences of the genes for the phenol hydroxylase have previously been determined, and found to composed of eight genes phlKLMNOPRX in an operon structure. The phlR, whose gene product is a NtrC-like transcriptional activator, was found to be located at the internal region of the structural genes, which is not the case in most bacteria where the regulatory genes lie near the structural genes. In addition to this regulatory gene, we found other regulatory genes, the phlA and phlR2, downstream of the phlX. These genes were found to be overlapped and hence likely to be co-transcribed. The protein similarity analysis has revealed that the PhlA belongs to the GntR family, which are known to be negative regulators, whereas the PhlR2 shares high homology with the NtrC-type family of transcriptional activators like the PhlR. Disruption of the phlA by insertional mutation has led to the constitutive expression of the activity of phenol hydroxylase in JMP134, indicating that PhlA is a negative regulator. Possible regulatory mechanisms of phenol metabolism in R. eutropha JMP134 has been discussed.

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소 Adipocyte Differentiation Related Protein (ADRP) 유전자의 Genomic Organization 및 Promoter Region의 특성 규명 (Genomic Organization and Characterization of the Promoter Region of Bovine ADRP (Adipocyte Different Related Protein) Gene)

  • 장요순;윤두학;김태헌;정일정;조진기
    • Journal of Animal Science and Technology
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    • 제45권2호
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    • pp.169-182
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    • 2003
  • ADRP 유전자가 24개월령 한우 등심조직에서 발현량이 급격히 증가하여 30개월령 등심조직에서는 발현량이 다소 감소하는 발현양상 분석결과로부터 이전 연구에서는 ADRP 유전자를 한우 성장단계 특이발현 유전자로 선정하였다. 본 연구에서는 ADRP 유전자의 발현조절 기작을 분석하기 위하여 promoter 영역을 포함하는 ADRP 유전자 전체영역을 cloning하였으며, 구조를 분석하고 promoter의 특성을 조사하였다. 한우 ADRP cDNA 단편을 probe로 합성하여 Southern blot 분석을 실시한 결과로부터 ADRP 유전자가 한우 genome 상에서 single copy로 존재하고 크기는 대략 12 kb에 해당하는 것을 확인하였다. Genomic DNA library screening을 실시하여 promoter 영역을 포함하는 ADRP 전체 유전자에 해당하는 clone을 확보하고 HwADRPg-1으로 명명한 후, 염기서열을 결정하고 분석하였다. 한우 ADRP 유전자, HwADRPg-1은 8개의 exon과 7개의 intron으로 구성되어 있으며 모든 exon-intron 경계는 GT/AG 원칙을 따르고 있었고, coding 영역은 7,633 bp로서 6개의 intron에 의해 7개의 exon으로 나누어져 있었다. HwADRPg-1의 promoter 영역에서는 TATAA box는 발견되지 않았으며, -70 위치에 근육 특이적 transcription activator인 Myo G 서열이 존재하였고, -629 위치에는 지방세포의 분화를 유도하는 것으로 알려진 C/EBP (CCAAT/enhancer binding protein) 서열이 존재하였다. HwADRPg-1의 조절영역에 있는 Myo G factor가 근육조직에서 ADRP 유전자가 발현될 수 있도록 하며, 근육의 발달정도를 신호로써 감지하여 근육조직에서 성장단계에 따른 ADRP 유전자의 발현량을 조절할 것으로 추정되고, 다른 종류의 지방세포 특이적인 전사인자 및 지방세포의 분화정도를 신호로 인식하는 전사단계 조절인자를 조사하기 위하여 promoter 영역의 추가분석이 이루어져야 할 것으로 사료된다.

SAMD4B, a novel SAM-containing protein, inhibits AP-1-, p53- and p21-mediated transcriptional activity

  • Luo, Na;Li, Guan;Li, Yongqing;Fan, Xiongwei;Wang, Yuequn;Ye, Xiangli;Mo, Xiaoyan;Zhou, Junmei;Yuan, Wuzhou;Tan, Ming;Xie, Huaping;Ocorr, Karen;Bodmer, Rolf;Deng, Yun;Wu, Xiushan
    • BMB Reports
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    • 제43권5호
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    • pp.355-362
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    • 2010
  • The sterile alpha motif (SAM) is a putative protein interaction domain involved in a wide variety of biological processes. Here we report the identification and characterization of a novel gene, SAMD4B, which encodes a putative protein of 694 amino acids with a SAM domain. Northern blot and RT-PCR analysis showed that SAMD4B is widely expressed in human embryonic and adult tissues. Transcriptional activity assays show SAMD4B suppresses transcriptional activity of L8G5-luciferase. Over-expression of SAMD4B in mammalian cells inhibited the transcriptional activities of activator protein-1 (AP-1), p53 and p21, and the inhibitory effects can be relieved by siRNA. Deletion analysis indicates that the SAM domain is the main region for transcriptional suppression. The results suggest that SAMD4B is a widely expressed gene involved in AP-1-, p53- and p21-mediated transcriptional signaling activity.

Regulation of signal transducer and activator of transcription 3 activation by dual-specificity phosphatase 3

  • Kim, Ba Reum;Ha, Jain;Kang, Eunjeong;Cho, Sayeon
    • BMB Reports
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    • 제53권6호
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    • pp.335-340
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    • 2020
  • Since cancer is the leading cause of death worldwide, there is an urgent need to understand the mechanisms underlying cancer progression and the development of cancer inhibitors. Signal transducer and activator of transcription 3 (STAT3) is a major transcription factor that regulates the proliferation and survival of various cancer cells. Here, dual-specificity phosphatase 3 (DUSP3) was identified as a regulator of STAT3 based on an interaction screening performed using the protein tyrosine phosphatase library. DUSP3 interacted with the C-terminal domain of STAT3 and dephosphorylated p-Y705 of STAT3. In vitro dephosphorylation assay revealed that DUSP3 directly dephosphorylated p-STAT3. The suppressive effects of DUSP3 on STAT3 were evaluated by a decreased STAT3-specific promoter activity, which in turn reduced the expression of the downstream target genes of STAT3. In summary, DUSP3 downregulated the transcriptional activity of STAT3 via dephosphorylation at Y705 and also suppressed the migratory activity of cancer cells. This study demonstrated that DUSP3 inhibits interleukin 6 (IL-6)/STAT3 signaling and is expected to regulate cancer development. Novel functions of DUSP3 discovered in IL-6/STAT3 signaling regulation would help expand the understanding of cancer development mechanisms.

Overexpression of OsNAC17 enhances drought tolerance in rice

  • Kim, Tae Hwan;Kim, Ju-Kon
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.168-168
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    • 2017
  • Drought conditions during cultivation reduce agricultural production yield less than a theoretical maximum yield under normal condition. Plant specific NAC transcription factors in rice are known to play an essential roles in stress resistance transcriptional regulation. In this study, we report the rice (Oryza sativa L japonica) NAM, AFTF and CUC transcription factor OsNAC17, which is predominantly induced by abiotic stress in leaf, was contribute to the drought tolerance mediated reactive oxygen species (ROS) in transgenic rice plants. Constitutive (PGD1) promoter was introduced to overexpress OsNAC17 and produced the transgenic PDG1:OsNAC17. Overexpression of OsNAC17 throughout the whole plant improved drought resistance phenotype at the vegetative stage. Morphological characteristics such as grain yield, grain filling rate, and total grain weight improved by 22~64% over wild type plants under drought conditions during the reproductive stage. The improved drought tolerance in transgenic rice was involved in reducing stomatal density up to 15% than in wild type plants and in increasing reactive oxygen species-scavenging enzyme. DEG profiling experiment identified 119 up-regulated genes by more than twofold (P<0.01). These genes included UDP-glycosyltransferase family protein, similar to 2-alkenal reductase (NADPH-dependent oxireductase), similar to retinol dehydrogenase 12, Lipoxygenase, and NB-ARC domain containing protein related in cell death. Furthermore, OsNAC17 was act as a transcriptional activator, which has an activation domain in C-terminal region. These result demonstrate that the overexpression of OsNAC17 improve drought tolerance by regulating ROS scavenging enzymes and by reducing stomatal density

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Transcriptional Regulation of the Methuselah Gene by Dorsal Protein in Drosophila melanogaster

  • Kim, Hyukmin;Kim, Jinsu;Lee, Yoonsoo;Yang, Jaeyeon;Han, Kyuhyung
    • Molecules and Cells
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    • 제21권2호
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    • pp.261-268
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    • 2006
  • The Drosophila methuselah (mth) mutant has an approximately 35 percent increase in average lifespan, and enhanced resistance to various forms of stress, including starvation, high temperature, and dietary paraquat. To examine the transcriptional regulation of mth, we used luciferase assays employing Drosophila S2 cells. Two positive control elements were found at -542 ~ -272 (PE1) and +28 ~ +217 (PE2), where putative binding sites for transcription factors including Dorsal (Dl) were identified. Cotransfection of a Dl expression plasmid with a mth-luciferase reporter plasmid resulted in decreased reporter activity. PE1 and PE2, the minimal elements for strong promoter activity, were required for maximal repression by Dl protein. The N-terminal Rel homology domain (RHD) of Dl was not sufficient for repression of mth. We demonstrated by chromatin affinity precipitation (ChAP) assays in S2 cells that Dl bound to the putative PE1 binding site. Unexpectedly, semi-quantitative RT-PCR analysis revealed that the level of mth transcripts was reduced in dl flies. However, the in vivo result support the view that mth expression is regulated by dl, since it is well known that Dl functions as both a transcriptional activator and repressor depending on what other transcription factors are present. These findings suggest that both innate immunity and resistance to stress are controlled by Dl protein.

HPV-18 E7 Interacts with Elk-1 Leading to Elevation of the Transcriptional Activity of Elk-1 in Cervical Cancer

  • Go, Sung-Ho;Rho, Seung Bae;Yang, Dong-Wha;Kim, Boh-Ram;Lee, Chang Hoon;Lee, Seung-Hoon
    • Biomolecules & Therapeutics
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    • 제30권6호
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    • pp.593-602
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    • 2022
  • The human papillomavirus (HPV)-18 E7 (E7) oncoprotein is a major transforming protein that is thought to be involved in the development of cervical cancer. It is well-known that E7 stimulates tumour development by inactivating pRb. However, this alone cannot explain the various characteristics acquired by HPV infection. Therefore, we examined other molecules that could help explain the acquired cancer properties during E7-induced cancer development. Using the yeast two-hybrid (Y2H) method, we found that the Elk-1 factor, which is crucial for cell proliferation, invasion, cell survival, anti-apoptotic activity, and cancer development, binds to the E7. By determining which part of E7 binds to which domain of Elk-1 using the Y2H method, it was found that CR2 and CR3 of the E7 and parts 1-206, including the ETS-DNA domain of Elk-1, interact with each other. As a result of their interaction, the transcriptional activity of Elk-1 was increased, thereby increasing the expression of target genes EGR-1, c-fos, and E2F. Additionally, the colony forming assay revealed that overexpression of Elk-1 and E7 promotes C33A cell proliferation. We expect that the discovery of a novel E7 function as an Elk-1 activator could help explain whether the E7 has novel oncogenic activities in addition to p53 inactivation. We also expect that it will offer new methods for developing improved strategies for cervical cancer treatment.

Transcriptional Upregulation of Plasminogen Activator Inhibitor-1 in Rat Primary Astrocytes by a Proteasomal Inhibitor MG132

  • Cho, Kyu Suk;Kwon, Kyoung Ja;Jeon, Se Jin;Joo, So Hyun;Kim, Ki Chan;Cheong, Jae Hoon;Bahn, Geon Ho;Kim, Hahn Young;Han, Seol Heui;Shin, Chan Young;Yang, Sung-Il
    • Biomolecules & Therapeutics
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    • 제21권2호
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    • pp.107-113
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    • 2013
  • Plasminogen activator inhibitor-1 (PAI-1) is a member of serine protease inhibitor family, which regulates the activity of tissue plasminogen activator (tPA). In CNS, tPA/PAI-1 activity is involved in the regulation of a variety of cellular processes such as neuronal development, synaptic plasticity and cell survival. To gain a more insights into the regulatory mechanism modulating tPA/PAI-1 activity in brain, we investigated the effects of proteasome inhibitors on tPA/PAI-1 expression and activity in rat primary astrocytes, the major cell type expressing both tPA and PAI-1. We found that submicromolar concentration of MG132, a cell permeable peptide-aldehyde inhibitor of ubiquitin proteasome pathway selectively upregulates PAI-1 expression. Upregulation of PAI-1 mRNA as well as increased PAI-1 promoter reporter activity suggested that MG132 transcriptionally increased PAI-1 expression. The induction of PAI-1 downregulated tPA activity in rat primary astrocytes. Another proteasome inhibitor lactacystin similarly increased the expression of PAI-1 in rat primary astrocytes. MG132 activated MAPK pathways as well as PI3K/Akt pathways. Inhibitors of these signaling pathways reduced MG132-mediated upregulation of PAI-1 in varying degrees and most prominent effects were observed with SB203580, a p38 MAPK pathway inhibitor. The regulation of tPA/PAI-1 activity by proteasome inhibitor in rat primary astrocytes may underlie the observed CNS effects of MG132 such as neuroprotection.

HDAC3 acts as a negative regulator of angiogenesis

  • Park, Deokbum;Park, Hyunmi;Kim, Youngmi;Kim, Hyuna;Jeoung, Dooil
    • BMB Reports
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    • 제47권4호
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    • pp.227-232
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    • 2014
  • Histone deacetylase-3 (HDAC3) is involved in cellular proliferation, apoptosis and transcriptional repression. However, the role of HDAC3 in angiogenesis remains unknown. HDAC3 negatively regulated the expression of angiogenic factors, such as VEGF and plasminogen activator inhibitor-1 (PAI-1). HDAC3 showed binding to promoter sequences of PAI-1. HDAC3 activity was necessary for the expression regulation of PAI-1 by HDAC3. VEGF decreased the expression of HDAC3, and the down-regulation of HDAC3 enhanced endothelial cell tube formation. HDAC3 negatively regulated tumor-induced angiogenic potential. We show the novel role of HDAC3 as a negative regulator of angiogenesis.