• Journal of Microbiology
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• 제44권1호
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• pp.11-22
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• 2006

Escherichia coli protein Rho is required for the factor-dependent transcription termination by an RNA polymerase and is essential for the viability of the cell. It is a homohexameric protein that recognizes and binds preferably to C-rich sites in the transcribed RNA. Once bound to RNA, it utilizes RNA-dependent ATPase activity and subsequently ATPase-dependent helicase activity to unwind RNA-DNA hybrids and release RNA from a transcribing elongation complex. Studies over the past few decades have highlighted Rho as a molecule and have revealed much of its mechanistic properties. The recently solved crystal structure could explain many of its physiological functions in terms of its structure. Despite all these efforts, many of the fundamental questions pertaining to Rho recognition sites, differential ATPase activity in response to different RNAs, translocation of Rho along the nascent transcript, interactions with elongation complex and finally unwinding and release of RNA remain obscure. In the present review we have attempted to summarize 'the knowns' and 'the unknowns' of the Rho protein revealed by the recent developments in this field. An attempt has also been made to understand the physiology of Rho in the light of its phylogeny.

• 동의생리병리학회지
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• 제18권6호
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• pp.1769-1776
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• 2004

The aim of this study was to find out the effects of the Yukmijihwangtang on transcription activity of Genes related to Bone Morphogenesis. For this purpose, experiments were performed to compare the polyphosphate contents of Yukmijihwangtang and its component herbs, and to verify their Effects on transcription activity of Genes related to Bone Morphogenesis. We know that Yukmijihwangtang and its component herbs have adequate amount of polyphosphate contents and have effects on transcription activity of Genes such as BMP1A, BMP2B, OTN, MGP, COL. In the conclusion, Yukmijihwangtang and its component herbs are strongly believed to have effectiveness on bone morphogenesis.

• Asian-Australasian Journal of Animal Sciences
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• 제31권3호
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• pp.449-456
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• 2018

Objective: Nanog, a homeodomain protein, has been investigated in humans and mice using embryonic stem cells (ESCs). Because of the limited availability of ESCs, few studies have reported the function and role of Nanog in porcine ESCs. Therefore, in this study, we investigated the location of the porcine Nanog chromosome and its basal promoter activity, which might have potential applications in development of ESCs specific marker as well as understanding its operating systems in the porcine. Methods: To characterize the porcine Nanog promoter, the 5'-flanking region of Nanog was isolated from cells of mini-pig ears. BLAST database search showed that there are two porcine Nanog genomic loci, chromosome 1 and 5, both of which contain an exon with a start codon. Deletion mutants from the 5'-flanking region of both loci were measured using the Dual-Luciferase Reporter Assay System, and a fluorescence marker, green fluorescence protein. Results: Promoter activity was detected in the sequences of chromosome 5, but not in those of chromosome 1. We identified the sequences from -99 to +194 that possessed promoter activity and contained transcription factor binding sites from deletion fragment analysis. Among the transcription factor binding sites, a Sp1 was found to play a crucial role in basal promoter activity, and point mutation of this site abolished its activity, confirming its role in promoter activity. Furthermore, gel shift analysis and chromatin immunoprecipitation analysis confirmed that Sp1 transcription factor binds to the Sp1 binding site in the porcine Nanog promoter. Taken together, these results show that Sp1 transcription factor is an essential element for porcine Nanog basal activity the same as in human and mouse. Conclusion: We showed that the porcine Nanog gene is located on porcine chromosome 5 and its basal transcriptional activity is controlled by Sp1 transcription factor.

• Natural Product Sciences
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• 제8권3호
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• pp.94-96
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• 2002

Four hundred varieties of plant extracts were screened for inhibitory activity against the NFAT transcription factor which plays an important role in inducing immune response. Among them, the MeOH extract of Cnidium officinale showed potent activity, and the activity-guided separation yielded butylidenephthalide, senkyunolide A and falcarindiol as the active constituents. The $IC_{50}$ value of butylidenephthalide was $1.3{\times}10^{-4}\;M$ and was similar to that of senkyunolide A $(2.1{\times}10^{-4}\;M)$. Interestingly, falcarindiol showed higher activity $(IC_{50},\;2.6{\times}10^{-5}\;M)$ than the two phthalides.

• 생약학회지
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• 제34권2호통권133호
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• pp.150-155
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• 2003

The nuclear factor of activated T cells (NFAT) protein induce transcription of cytokine genes required for T-cell activation, including the IL-2 gene. Activation of NFAT normally plays a significant role in inducing immune response. However, excessive activation provokes immunopathological reactions including autoimmunity, transplant rejection and inflammation. Thus, several natural products were screened on the inhibitory activity against the NFAT transcription factor. Among them, Euonymus sieboldiana showed strong inhibitory activity against the NFAT transcription factor without affecting cell viability.

• Genomics & Informatics
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• 제1권2호
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• pp.113-118
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• 2003

Among a number of antigens characterized in M leprae, an etiological agent of Leprosy, the 18 kDa antigen, is unique to M leprae. We have previously determined a sequence specific element in the 18 kDa gene of M leprae, which confers transcriptional repression. In this report, we have examined if the element could be applied to genes other than the 18 kDa gene of M leprae. To identify the roles of the regulatory sequence in heterologous promoter, we have constructed pB3 vector series, which contains BCG hsp65 promoter and the M leprae 18 kDa transcription repression responsive element in tandem using LacZ gene as a reporter gene. Cloning of hsp65 promoters of M bovis BCG or M smegmatis in front of LacZ gene resulted in normal $\beta$­galactosidase activity as expected. However, when the sequence element was placed between the promoter and the LacZ gene, $\beta$-galactosidase activity was reduced 10-fold less. Also we have examined with pB3(-) vector, that harbors the transcription repression responsive element in a reversed orientation, the $\beta$-galactosidase activity was found to be similar to pB3(+) vector. Thus, these results further confirm that M leprae 18 kDa transcription repression responsive element could regulate BCG hsp65 heterologous promoter and that the element could act as an operator for the transcription of mycobacteria.

• 미생물학회지
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• 제34권4호
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• pp.248-253
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• 1998

Esherichia coli(E. coli) K12 균주를 숙주세포로 삼는 박테리오파아지인 N4는 single-stranded DNA에 결합하는 단백질인 N4SSB(bacteriophage N4-coded single-stranded DNA-binding protein) 단백질을 만든다. N4SSB 단백질은 N4 DNA replication 뿐만 아니라 late transcription과 N4 DNA recombination에도 필요한 여러 가지 기능을 가진 단백질이다. N4 late transcription은 숙주세포인 E. coli의 $E{\sigma}^{70}$ RNA polymerase에 의해서 수행이 되나 N4SSB 단백질을 반드시 필요로 하기 때문에 N4SSB 단백질이 생성될 때까지는 N4 late promoter로부터 RNA 합성이 일어나지 않는다. 본 연구에서는 N4SSB의 N4 DNA replication과 late transcription, 그리고 N4 DNA recombination에 필요한 영역(domain)을 알아내기 위해서 여러 가지 돌연변이형 N4SSB 단백질을 만들어 N4 DNA replication과 late transcription, 그리고 N4 DNA recombination의 3가지 작용에 대한 in vivo 활성을 조사 분석하였다. 그 결과 N4SSB 단백질의 C-말단기에 있는 7개의 아미노산이 N4SSB 단백질의 활성에 중요하다는 것을 알 수 있었다. 특히 C-말단기의 7개의 아미노산에는 세 개의 lysine이 포함되어 있는데 이 lysine이 N4SSB 단백질의 활성에 중요한 역할을 한다는 것이 제시되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제28권2호
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• pp.113-120
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• 2024

Solute carrier 40A1 (SLC40A1) encodes ferroportin, which is the only known transmembrane protein that exports elemental iron from mammalian cells and is essential for iron homeostasis. Mutations in SLC40A1 are associated with iron-overload disorders. In addition to ferroportin diseases, SLC40A1 expression is downregulated in various cancer types. Despite the clinical significance of the SLC40A1 transporter, only a few studies have investigated genetic variants in SLC40A1. The present study was performed to identify genetic variations in the SLC40A1 promoter and functionally characterize each variant using in vitro assays. We investigated four haplotypes and five variants in the SLC40A1 promoter. We observed that haplotype 3 (H3) had significantly lower promoter activity than H1, whereas the activity of H4 was significantly higher than that of H1. Luciferase activity of H2 was comparable to that of H1. In addition, four variants of SLC40A1, c.-1355G>C, c.-662C>T, c.-98G>C, and c.-8C>G, showed significantly increased luciferase activity compared to the wild type (WT), whereas c.-750G>A showed significantly decreased luciferase activity compared to the WT. Three transcription factors, cAMP response element-binding protein-1 (CREB-1), chicken ovalbumin upstream promoter transcription factor 1, and hepatic leukemia factor (HLF), were predicted to bind to the promoter regions of SLC40A1 near c.-662C>T, c.-98G>C, and c.-8C>G, respectively. Among these, CREB1 and HLF bound more strongly to the variant sequences than to the WT and functioned as activators of SLC40A1 transcription. Collectively, our findings indicate that the two SLC40A1 promoter haplotypes affect SLC40A1 transcription, which is regulated by CREB-1 and HLF.

• 대한의생명과학회지
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• 제29권3호
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• pp.103-108
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• 2023

Enhancers are cis-elements to regulate transcription of cell/tissue-specific genes in multicellular organisms. These elements locate in upstream or downstream regions of target genes and are found in a long distance up to 100 Kb in some cases. Transcription factors and coactivators bind to enhancers in a chromatin environment. Enhancers appear to facilitate the transcription of target genes by communicating with promoters and activating them. As transcription activation mechanism of enhancers, chromatin looping between enhancers and promoters, tracking of enhancer activity to promoters along the intervening regions, and movement of enhancers and promoters into transcription condensates have been suggested based on various molecular and cellular biology studies. These mechanisms are likely to act together rather than exclusive each other for gene transcription. Understanding of enhancer action mechanism may provide a way to regulate the transcription of cell/tissue-specific genes relating with aging or various diseases.

• Molecules and Cells
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• 제22권2호
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• pp.163-167
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• 2006

Histone deacetylase (HDAC) activity is commonly associated with transcriptional repression. However, there is also evidence for a function in transcriptional activation. Previous studies have demonstrated a fundamental role of deacetylase activity in $IFN{\alpha}$-responsive gene transcription. In the case of type II IFN ($IFN{\gamma}$) results are controversial: some genes require HDAC activity, while transcription of others is repressed by HDAC. To investigate the effect of HDAC on transcription of an $IFN{\gamma}$-activated gene, real-time PCR was used to measure CXCL10 mRNA in Hela cells stimulated with $IFN{\gamma}$ in the presence or absence of the HDAC inhibitor TSA. Chromatin imunoprecipitation combined with real-time PCR was used to check acetylation of histone H4 and recruitment of the STAT1 complex to the ISRE locus of the CXCL10 gene. Activation of CXCL10 transcription in response to $IFN{\gamma}$ was paralleled by a decrease in histone H4 acetylation and an increase in recruitment of the STAT1 complex to the CXCL10 ISRE locus. The transcription of CXCL10 and histone H4 deacetylation were blocked by TSA, but the latter had no obvious affect on recruitment of the STAT1 complex. Our data indicate that $IFN{\gamma}$ and STAT-dependent gene transcription requires the participation of HDAC, as does the $IFN{\alpha}$-STAT pathway.