Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To define the mechanisms of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced transcription of the ornithine decarboxylase (ODC) gene, we isolated a genomic clone (hODC41B) of ODC from a human leukocyte genomic DNA library. The restriction endonuclease map, in comparison with the previously published sequences of the human ODC gene, indicated that hODC41B contained a 15.7-kb sequence that extended from the sixth exon to about 10 kb upstream of the ODC gene. A 2.5-kb genomic fragment containing the 5' flanking region and the first exon was subcloned and sequenced. Sequence analysis revealed multiple putative promoter/enhancer elements (a TATA box, a CAAT box, 17 GC boxes, and a cAMP-responsive element) but no consensus AP-1 sequences (TGAGTCA) in the 2.5-kb 5' flanking region. However, three AP-1 sequences were located in introns 3, 5, and 11. We constructed a series of chimeric genes containing part of the first exon and increasingly longer 5' flanking sequences of the ODC gene fused to either bacterial chloramphenicol acetyltransferase (CAT) or luciferase reporter genes. TPA inducibility was determined by transient transfection and measurement of CAT or luciferase expression in HeLa cells. The induction of CAT activity by TPA decreased with decreasing lengths of the 5' flanking sequences up to nt -82. The TPA induction from the construct -72 ODC CAT was threefold to sevenfold, and the TPA inducibility of the same fragment was about ninefold to 30-fold with the luciferase reporter gene. Further deletion analysis revealed TPA-responsive sequences in ODC nt -42 to +54. Gel mobility shift assays using alpha-32P-end labeled ODC nt -42 to +60 revealed that nt -42 to +60 specifically bound HeLa cell nuclear proteins. HeLa cell nuclear protein binding to ODC nt -42 to +60 could not be completely competed by AP-1-, AP-2-, AP-3-, or SP1-responsive sequences.
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PMID:Non-AP-1 tumor promoter 12-O-tetradecanoylphorbol-13-acetate-responsive sequences in the human ornithine decarboxylase gene. 804 98

We have isolated and characterized a genomic clone, lambda AOSG11, corresponding to aox1, which encodes the 42 kDa alternative oxidase precursor protein of Sauromatum guttatum Schott. The sequence of lambda AOSG11 revealed that aox1 consists of four exons separated by three short introns. Exon three contains the region of aox1 that (1) is highly conserved in the corresponding genes of potato, rice, and yeast, and (2) encodes a region of the deduced protein that is predicted to form two transmembrane alpha-helices. Southern blot analysis of restriction endonuclease-digested genomic DNA, indicated that aox1 is a single, nuclear-encoded gene in S. guttatum. We have determined the transcriptional start site of aox1 using nuclease protection and primer extension experiments. Comparison of the putative promoter region of aox1 to promoters of PR1a and GRP8 revealed some sequence similarity.
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PMID:The salicylic acid-inducible alternative oxidase gene aox1 and genes encoding pathogenesis-related proteins share regions of sequence similarity in their promoters. 844 61

We have previously demonstrated that Yersinia ruckeri resists cecropin B in an inducible manner. In this study, we sought to identify the molecular changes responsible for the inducible cecropin B resistance of Y. ruckeri. Differences in gene expression associated with the inducible resistance were investigated. Cultures of Y. ruckeri were exposed to a sublethal concentration of cecropin B and resultant changes in the messenger RNA population of the bacteria were assayed using the differential display reverse transcription polymerase chain reaction (DD-RT-PCR). A single band was consistently increased in intensity in all repeats of the experiment. The band was excised, cloned, sequenced, and used to screen a Y. ruckeri genomic DNA library. The DD-RT-PCR fragment shared 100% identity to the cDNA sequence of an ATP-dependent endonuclease of the overcome lysogenization defect (OLD) family of Y. ruckeri 29473. The genomic clone that was recovered was not identical to the DD-RT-PCR clone, but harbored a gene for a secreted endonuclease 1 (nucM) homologue. It was determined that transcription of the gene was upregulated following exposure to cecropin B via RT-PCR. Furthermore, an increase in the nuclease activity of culture supernatants of Y. ruckeri following exposure to cecropin B was demonstrated. These findings demonstrate that cecropin B exposure increases the expression of at least two endonucleases in Y. ruckeri. The production and secretion of an endonuclease by Y. ruckeri in response to an antimicrobial peptide indicates the involvement of both intracellular and extracellular DNA in the toxic effects of cecropin B.
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PMID:Molecular cloning of cecropin B responsive endonucleases in Yersinia ruckeri. 2035 73

In Drosophila, telomere retrotransposons counterbalance the loss of telomeric DNA. The exceptional mechanism of telomere recovery characterized in Drosophila has not been found in lower dipterans (Nematocera). However, a retroelement resembling a telomere transposon and termed "RaTART" has been described in the nematoceran Rhynchosciara americana. In this work, DNA and protein sequence analyses, DNA cloning, and chromosomal localization of probes obtained either by PCR or by screening a genomic library were carried out in order to examine additional features of this retroelement. The analyses performed raise the possibility that RaTART represents a genomic clone composed of distinct repetitive elements, one of which is likely to be responsible for its apparent enrichment at chromosome ends. RaTART sequence in addition allowed to assess a novel subtelomeric region of R. americana chromosomes that was analyzed in this work after subcloning a DNA fragment from a phage insert. It contains a complex repeat that is located in the vicinity of simple and complex tandem repeats characterized previously. Quantification data suggest that the copy number of the repeat is significantly lower than that observed for the ribosomal DNA in the salivary gland of R. americana. A short insertion of the RaTART was identified in the cloned segment, which hybridized preferentially to subtelomeres. Like RaTART, it displays truncated sequences related to distinct retrotransposons, one of which has a conceptual translation product with significant identity with an endonuclease from a lepidopteran retrotransposon. The composite structure of this DNA stretch probably reflects mobile element activity in the subtelomeric region analyzed in this work.
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PMID:Curiously composite structures of a retrotransposon and a complex repeat associated with chromosome ends of Rhynchosciara americana (Diptera: Sciaridae). 2060 98


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