67 research outputs found

    Poly[μ-chlorido-[μ4-5-(4-pyrid­yl)tetra­zol­ato]dicopper(I)]

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    The title three-dimensional coordination polymer, [Cu2Cl(C6H4N5)]n, is the product of the hydro­thermal reaction of CuCl2·2H2O and 5-(4-pyrid­yl)-1H-tetra­zole (4-Hptz). The two independent CuI ions are coordinated in distorted tetra­hedral and distorted trigonal coordination environments. In the unique 5-(4-pyrid­yl)-1H-tetra­zolate ligand, the dihedral angle between the pyridine and tetra­zole rings is 17.3 (2)°

    1,3-Dicyclo­hexyl-1-isonicotinoylurea monohydrate

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    The title organic compound, C19H27N3O2·H2O, was synthesized from methyl­ene dicyclo­hexyl­amine, 4-pyridine­carboxylic acid and N,N′-dicyclo­hexyl­carbodiimide. The water molecule is involved in inter­molecular hydrogen bonds, linking symmetry-related urea mol­ecules into a two-dimensional supra­molecular ladder-like structure

    AP4 transcription factor binding site is a repressor element in ek2 promoter of human liver carcinoma cell line, HepG2

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    Ethanolamine kinase (EK) is the first enzyme in the Kennedy pathway for the biosynthesis of phosphatidylethanolamine. Although EK has been reported to be involved in phospholipid biosynthesis, carcinogenesis, cell growth, muscle development and sex determination during embryonic development, little is known about its transcriptional regulation by endogenous or exogenous signals. Human EK exists as EK1, EK2α and EK2β isoforms, encoded by two separate genes, named ek1 and ek2. Compared to ek1 gene, ek2 is expressed at a higher level in liver and EK2 isoforms also accept choline as substrate besides ethanolamine, which could contribute to liver carcinogenesis. The main aim of this study was to analyze and characterize the human ek2 promoter in cultured mammalian cells. Human ek2 (2011 bp) promoter was cloned into reporter vector, pGL4.10 [luc2] and the promoter activities were studied in human liver carcinoma (HepG2 cells). Sequence analyses showed that ek2 promoter contains numerous putative transcription factor binding sites including AP4 and it is devoid of a recognizable consensus TATA box but it contains a high number of guanine (G) and cytosine (C) nucleotides. PCR mutagenesis of three nucleotides at E-box motif of AP4 transcription binding site located between -293 and -276 of ek2 promoter was successfully performed to show that AP4 transcription factor binding site acts as a repressive element in the regulation of ek2 expression. AP4 upregulation has been implicated in bad prognosis of carcinoma, therefore the regulatory role of AP4 binding site reported in this study could be a link between ek2 and carcinogenesis. Although further studies need to be carried out to understand and to determine the repression mechanism of AP4 in ek2 promoter, the characterization and analysis of ek promoter performed in this study provide important understanding of its basal transcriptional regulation which would allow us to control ek expression levels in pathologic conditions that involve this gene

    Structural Modeling and Biochemical Characterization of Recombinant KPN_02809, a Zinc-Dependent Metalloprotease from Klebsiella pneumoniae MGH 78578

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    Klebsiella pneumoniae is a Gram-negative, cylindrical rod shaped opportunistic pathogen that is found in the environment as well as existing as a normal flora in mammalian mucosal surfaces such as the mouth, skin, and intestines. Clinically it is the most important member of the family of Enterobacteriaceae that causes neonatal sepsis and nosocomial infections. In this work, a combination of protein sequence analysis, structural modeling and molecular docking simulation approaches were employed to provide an understanding of the possible functions and characteristics of a hypothetical protein (KPN_02809) from K. pneumoniae MGH 78578. The computational analyses showed that this protein was a metalloprotease with zinc binding motif, HEXXH. To verify this result, a ypfJ gene which encodes for this hypothetical protein was cloned from K. pneumoniae MGH 78578 and the protein was overexpressed in Escherichia coli BL21 (DE3). The purified protein was about 32 kDa and showed maximum protease activity at 30 °C and pH 8.0. The enzyme activity was inhibited by metalloprotease inhibitors such as EDTA, 1,10-phenanthroline and reducing agent, 1,4-dithiothreitol (DTT). Each molecule of KPN_02809 protein was also shown to bind one zinc ion. Hence, for the first time, we experimentally confirmed that KPN_02809 is an active enzyme with zinc metalloprotease activity

    Вихретоковый анизотропный термоэлектрический первичный преобразователь лучистого потока

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    Представлена оригинальная конструкция первичного преобразователя лучистого потока, который может служить основой для создания приемника неселективного излучения с повышенной чувствительностью

    Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

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    Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

    Sp1 and Sp3 Are the Transcription Activators of Human ek1 Promoter in TSA-Treated Human Colon Carcinoma Cells.

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    Ethanolamine kinase (EK) catalyzes the phosphorylation of ethanolamine, the first step in the CDP-ethanolamine pathway for the biosynthesis of phosphatidylethanolamine (PE). Human EK exists as EK1, EK2α and EK2β isoforms, encoded by two separate genes, named ek1 and ek2. EK activity is stimulated by carcinogens and oncogenes, suggesting the involvement of EK in carcinogenesis. Currently, little is known about EK transcriptional regulation by endogenous or exogenous signals, and the ek gene promoter has never been studied.In this report, we mapped the important regulatory regions in the human ek1 promoter. 5' deletion analysis and site-directed mutagenesis identified a Sp site at position (-40/-31) that was essential for the basal transcription of this gene. Treatment of HCT116 cells with trichostatin A (TSA), a histone deacetylase inhibitor, significantly upregulated the ek1 promoter activity through the Sp(-40/-31) site and increased the endogenous expression of ek1. Chromatin immunoprecipitation assay revealed that TSA increased the binding of Sp1, Sp3 and RNA polymerase II to the ek1 promoter in HCT116 cells. The effect of TSA on ek1 promoter activity was cell-line specific as TSA treatment did not affect ek1 promoter activity in HepG2 cells.In conclusion, we showed that Sp1 and Sp3 are not only essential for the basal transcription of the ek1 gene, their accessibility to the target site on the ek1 promoter is regulated by histone protein modification in a cell line dependent manner

    The development and practice of strategic environmental assessment (SEA) in Kenya

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    This paper provides an analytical description of the emerging Kenyan Strategic Environmental assessment (SEA) system as an example from Sub-Sahara Africa, focusing on its form, purposes and implementation. Three features are of particular interest: first, the extent to which the Kenyan SEA operates within a formally recognized regulatory framework of protected rights; second, the policies and institutions which act as agencies of the SEA system; and third, the procedural and substantive requirements of the Kenyan SEA process. It is concluded that the current political and decision-making context, following the new constitution, has created a well-protected and enforceable regulatory system for SEA. However, the successful development of SEA in Kenya will likely depend on 1) internalization and subsequent innovative application of the existing framework; 2) the effective integration of SEA at both the national and regional levels; 3) the level of commitment SEA will get from the emerging political and decision-making cultures; and 4) continuous use of empirical and evaluatory feedback to evolve the system
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