Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:4.1.99.3 (PRE)
1,923 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have investigated the developmental and tissue specific expression of the human embryonic zeta-globin gene in transgenic mice. A construct containing 550 bp of zeta-globin 5' flanking region, fused to a beta-galactosidase (lacZ) reporter gene and linked to the locus control region (LCR)-like alpha positive regulatory element (alpha PRE) was employed for the production of transgenic mice. Firstly, we compared the number of live born transgenic mice containing this construct to the number of live born transgenic mice containing the entire zeta-globin gene linked to the alpha PRE or the beta LCR. Data showed that 12% of mice generated from eggs injected with zeta-promoter/lacZ/alpha PRE DNA were transgenic compared to only 2% of mice generated from eggs injected with the entire zeta-globin gene linked to the alpha PRE or the beta LCR. The reduced number of live born transgenic mice containing the latter constructs suggests that death of transgenic embryos, possibly due to thalassaemia, may be occurring. X-gal staining of whole embryos containing the lacZ gene revealed that zeta-globin promoter activity was most pronounced at 8.5-9.5 days of development and was restricted to erythroid cells. By 15 days of development, no zeta-globin promoter activity was detected. These results suggest that the alpha PRE can direct high level expression from the zeta-globin promoter and that sequences required for the correct tissue and developmental specific expression of the human zeta-globin gene are present within 550 bp's of 5' flanking region. Sequences within the body of the zeta-globin gene or 3' of the cap site do not appear to be necessary for correct zeta-globin developmental regulation.
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PMID:The developmental regulation of the human zeta-globin gene in transgenic mice employing beta-galactosidase as a reporter gene. 145 28

The glucocorticoid receptor (GR) and the progestin receptor (PR) bind specifically to a variety of DNA sequences, glucocorticoid/progestin response elements (GRE/PRE), located in the proximity of responsive gene promoters. Using the isolated recombinant GR DNA-binding domain (DBD), it has recently been shown that GR interacts with the GRE/PRE, a 15-basepair partially palindromic consensus sequence, as a dimer. In this study an investigation into the GR-GRE/PRE and PR-GRE/PRE interaction has been performed using missing base contact analysis with the tyrosine aminotransferase GREII (TATII) and recombinant GR DBD as well as a fusion protein consisting of the PR DBD fused to Staph. aureus protein-A. GR and PR had identical base contact points, localized within two consecutive major grooves, binding to the same face of the DNA. Ethylation interference was also performed on the GR DBD-TATII interaction. The contact points with the backbone phosphate groups flank the contacts within the major groove for each of the two half-sites. Knowledge of the contact points within the DNA sequence together with the three-dimensional structure of the protein enables modelling of the protein-DNA interaction.
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PMID:Identification of protein contact sites within the glucocorticoid/progestin response element. 192 92

Bacterially-expressed fusion proteins containing the DNA-(region C) or hormone-binding (region E) domains of the chicken progesterone receptor (cPR) fused to the C terminus of Escherichia coli beta-galactosidase were analysed for the specificity of interaction with natural and synthetic hormone-responsive elements (HREs) and progestins, respectively. The purified fusion protein containing the progestin-binding domain bound progesterone with an apparent Kd of 1.0-1.5 nM and was specifically photocross-linked with the synthetic progestin R5020 in crude bacterial lysates. Labelling of intact bacterial cells with [3H]R5020 revealed that the majority, if not all, of the bacterially produced hormone-binding domain was active. No differences in the binding to a synthetic palindromic glucocorticoid/progestin-responsive element (GRE/PRE) were found when the bacterially produced cPR DNA-binding domain was compared in methylation interference assays with the full-length chicken progesterone receptor form A expressed in eukaryotic cells. The study of dissociation kinetics, however, revealed differences in the half-life of the complexes formed between the palindromic GRE/PRE and either the receptor form A or the fusion protein containing the cPR DNA-binding domain. DNase I protection experiments demonstrated that the bacterially produced region C of the cPR generated specific 'footprints' on the mouse mammary tumour virus long terminal repeat (MMTV-LTR) which were nearly identical to those previously reported for the rat glucocorticoid receptor.
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PMID:Expression of active hormone and DNA-binding domains of the chicken progesterone receptor in E. coli. 254 Sep 61

A 2 kb fragment was isolated from an Anacystis nidulans genomic DNA library by hybridization with synthetic oligonucleotide probes derived from the N-terminal amino acid sequence of Anacystis photolyase. This fragment contains a 1452 bp-long open reading frame encoding a polypeptide of 484 amino acids (Mr 54475). Antibodies raised against purified Anacystis photolyase reacted with extracts of cells harboring fused genes between lacZ of Escherichia coli and this gene. A 40.7% similarity was found between the deduced amino acid sequences of Anacystis and E. coli photolyases, notwithstanding the difference in chromophore structure.
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PMID:Cloning and characterization of a photolyase gene from the cyanobacterium Anacystis nidulans. 283 35

Cultured human and embryonic chick fibroblasts possess different enzyme-mediated processes to repair cyclobutyl pyrimidine dimers induced in their deoxyribonucleic acid (DNA) by ultraviolet (UV) radiation. While dimers are corrected in human cells by excision repair, a photoenzymatic repair process exists in embryonic chick cells for the removal of these potentially deleterious UV photoproducts. We have utilized a sensitive enzymatic assay to monitor the disappearance, i.e. repair, of dimer-containing sites in fused populations of human and chick cells primarily consisting of multinucleate human/chick heterokaryons. Fused cultures were constructed such that UV photoproducts were present only in chick DNA when evaluating excision repair and only in human DNA when evaluating photoenzymatic repair. Based on the kinetics of site removal observed in these cultures we are led to conclude the following: Within heterokaryons per se the photoreactivating enzyme derived from chick nuclei and at least one excision-repair enzyme (presumably a UV endonuclease) derived from human nuclei act on UV-damaged DNA in foreign nuclei with an efficiency equal to that displayed toward their own nuclear DNA. Hence, after cell fusion these chick and human repair enzymes are apparently able to diffuse into foreign nuclei and once therein competently attack UV-irradiated DNA independently of its origin. In harmony with the situation in nonfused parental cultures, in heterokaryons the chick photoenzymatic repair process rapidly removed all dimer-containing sites from human DNA including the residual fraction normally acted upon slowly by the human excision-repair process.
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PMID:DNA repair in human/embryonic chick heterokaryons. Ability of each species to aid the other in the removal of ultraviolet-induced damage. 447 28

We isolated and characterized mouse photolyase-like genes, mCRY1 (mPHLL1) and mCRY2 (mPHLL2), which belong to the photolyase family including plant blue-light receptors. The mCRY1 and mCRY2 genes are located on chromosome 10C and 2E, respectively, and are expressed in all mouse organs examined. We raised antibodies specific against each gene product using its C-terminal sequence, which differs completely between the genes. Immunofluorescent staining of cultured mouse cells revealed that mCRY1 is localized in mitochondria whereas mCRY2 was found mainly in the nucleus. The subcellular distribution of CRY proteins was confirmed by immunoblot analysis of fractionated mouse liver cell extracts. Using green fluorescent protein fused peptides we showed that the C-terminal region of the mouse CRY2 protein contains a unique nuclear localization signal, which is absent in the CRY1 protein. The N-terminal region of CRY1 was shown to contain the mitochondrial transport signal. Recombinant as well as native CRY1 proteins from mouse and human cells showed a tight binding activity to DNA Sepharose, while CRY2 protein did not bind to DNA Sepharose at all under the same condition as CRY1. The different cellular localization and DNA binding properties of the mammalian photolyase homologs suggest that despite the similarity in the sequence the two proteins have distinct function(s).
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PMID:Characterization of photolyase/blue-light receptor homologs in mouse and human cells. 980 4

The human T cell leukemia virus type-1 (HTLV-1) is the etiologic agent of adult T cell leukemia (ATL). Since the HTLV-I-encoded transactivator Tax has been shown to activate many cellular genes including cytokine genes interleukin (IL-)1alpha, 2, 5, 6, 8, 10 and 15, we ask whether Tax also affects IL-4 expression. In this study, we show that addition of recombinant Tax proteins greatly enhances IL-4 secretion in human peripheral primary T cells. Transient transfection studies showed that ectopic expression of Tax significantly enhanced IL-4 promoter activity. The IL-4 promoter contains a strong NF-IL6 (PRE-I element) and a NF-AT/NF-kappaB overlapping site (P1 element). We show that expression of Tax stimulates NF-IL6 binding to the PRE-I element and, consequently, enhances PRE-I-mediated transcriptional activity. Using Jurkat T cell lines which stably express Tax fused to the hormone binding domain of the human estrogen receptor (ER), we show that Tax enhances endogenous IL-4 mRNA expression and increases IL-4 promoter activity in a hormone-dependent manner. Mutation analysis revealed that the IL-4 PRE-I (NF-IL6 site) and the P1 (NF-AT/NF-kappaB site) are involved in Tax-mediated transactivation. Our studies provide the first evidence of the functional involvement of Tax in IL-4 gene regulation.
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PMID:Human T cell leukemia virus type I Tax enhances IL-4 gene expression in T cells. 1153 60

The longest hepatitis B virus transcript is a 3.9-kb mRNA whose function remained unclear. In this study, we wished to identify the translation products and physiological role of this viral transcript. This transcript initiates from the X promoter region ignoring the inefficient and noncanonical viral polyadenylation signal at the first round of transcription. However, an HBV mutant with canonical polyadenylation signal continues, though with lower efficiency, to program the synthesis of this long transcript, indicating that the deviated HBV polyadenylation signal is important but not essential to enable transcription of the 3.9-kb species. The 3.9-kb RNA contains two times the X open reading frame (ORF). The X ORF at the 5'-end is positioned upstream of the CORE gene. By generating an HBV DNA mutant in which the X and Core ORFs are fused, we demonstrated the production of a 40-kDa X-Core fusion protein that must be encoded by the 3.9-kb transcript. Mutagenesis studies revealed that the production of this protein depends on the 5' X ORF ATG, suggesting that the 3.9-kb RNA is active in translation of the X ORF. Based on these features, the 3.9-kb transcript was designated lxRNA for long X RNA. Unlike other HBV transcripts, lxRNA harbors two copies of PRE, the posttranscriptional regulatory element that controls the nuclear export of HBV mRNAs. Unexpectedly, despite the presence of PRE sequences, RNA fractionation analysis revealed that lxRNA barely accumulates in the cytoplasm, suggesting that nuclear export of lxRNA is poor. Collectively, our data suggest that two distinct HBV mRNA species encode pX and that the HBV transcripts are differentially regulated at the level of nuclear export.
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PMID:A long HBV transcript encoding pX is inefficiently exported from the nucleus. 1275 80

The 266 kbp genome sequence of plaque-purified, tissue culture-adapted, attenuated European Fowlpox virus FP9 has been determined and compared with the 288 kbp sequence of a pathogenic US strain (FPVUS). FP9 carries 244 of the 260 reported FPVUS ORFs (both viruses also have an unreported orthologue of conserved poxvirus gene A14.5L). Relative to FPVUS, FP9 differed by 118 mutations (26 deletions, 15 insertions and 77 base substitutions), affecting FP9 equivalents of 71 FPVUS ORFs. To help to identify mutations involved in adaptation and attenuation, the virulent parent of FP9, HP1, was sequenced at positions where FP9 differed from FPVUS. At 68 positions, FP9 and HP1 sequences were identical, reflecting differences between American and European lineages. Mutations at the remaining 50 positions in FP9 relative to FPVUS and HP1, involving 46 ORFs, therefore accounted for adaptation and attenuation. ORFs deleted during passage included those encoding members of multigene families: 12 ankyrin repeat proteins, three C-type lectin-like proteins, two C4L/C10L-like proteins, one G-protein coupled receptor protein, one V-type Ig domain protein, two N1R/p28 proteins and one EFc family protein. Tandem ORFs encoding Variola virus B22R orthologues were fused by a 5.8 kbp deletion. Single-copy genes disrupted or deleted during passage included those encoding a homologue of murine T10, a conserved DNA/pantothenate metabolism flavoprotein, photolyase, the A-type inclusion protein and an orthologue of vaccinia A47L. Gene assignments have been updated for DNase II/DLAD, binding proteins for IL-18 and interferon-gamma, phospholipid hydroperoxide glutathione peroxidase (PHGPX/GPX-4) and for a highly conserved homologue of ELOVL4.
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PMID:Comparison of the genome sequence of FP9, an attenuated, tissue culture-adapted European strain of Fowlpox virus, with those of virulent American and European viruses. 1476 88

Escherichia coli DNA photolyase was expressed as C-terminal 6x histidine-fused protein. Purification of His-tagged E. coli DNA photolyase was developed using immobilized metal affinity chromatography with Chelating Sepharose Fast Flow. By one-step affinity chromatography, approximate 4.6 mg DNA photolyase was obtained from 400 ml E. coli culture. The purified His-tagged enzyme was combined with two chromophors, FADH and MTHF. Using the oligonucleotide containing cyclobutane pyrimidine dimer as substrate, both reversed-phase high-performance liquid chromatography and size-exclusion high-performance liquid chromatography were developed to measure the enzyme activity. The enzyme was found to be able to repair the cyclobutane pyrimidine dimer with the turnover rate of 2.4 dimers/photolyase molecule/min.
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PMID:Activity assay of His-tagged E. coli DNA photolyase by RP-HPLC and SE-HPLC. 1591 8


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