Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The promoter region of the epidermal growth factor (EGF) receptor has been identified by in vitro transcription using EGF receptor genomic DNA fragments as template and by primer extension and nuclease S1 mapping using EGF receptor mRNA. Six transcriptional start sites were identified. DNA sequence analysis shows that the promoter region contains neither a "TATA box" nor a "CAAT box," has an extremely high G+C content (88%), and contains five CCGCCC repeats and four (TCC)TCCTCCTCC repeats. This promoter region is situated close to or within a DNase I-hypersensitive site in A431 human epidermoid carcinoma cells, which overproduce the EGF receptor. The EGF receptor gene promoter has some resemblance to the promoter of the hydroxymethylglutaryl-CoA reductase gene and the early promoter of simian virus 40. This similarity may offer a clue to the mechanism by which the receptor gene is regulated.
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PMID:Characterization and sequence of the promoter region of the human epidermal growth factor receptor gene. 299 99

We previously have shown that homologs of the outer domain segment of the inverted repeat termini (IVR-OD) of the sea urchin TU transposons are conserved among multiple eucaryotic species, including humans. We report here that two cloned human DNA IVR-OD homologs, Hut2 and Hut17, consist of a series of tandem repeats of the trimer AGG/TCC, forming segments (313 and 221 base pairs in length, respectively) of polypurine/polypyrimidine (pPu/pPy or "Puppy") asymmetry in the two DNA strands; these are punctuated at certain sites with variant trimers, which are different for the two clones. Sequences homologous to the Hut2 pPu/pPy tract exist at multiple sites in the DNA of a wide variety of eucaryotes. Hybridization of human DNA with a Hut2 probe or with a previously described chicken DNA pPu/pPy sequence indicates that pPu/pPy sequences can be grouped into families distinguishable by the extent of their homology with each probe at different hybridization stringencies. Moreover, particular pPu/pPy tracts show species-specific differences in their distribution. Both the Hut2 and Hut17 pPu/pPy tracts are cleaved by S1 nuclease when tested on supercoiled plasmids. Most if not all of the 313-base-pair Hut2 pPu/pPy tract is also sensitive to S1 in its native location in HeLa cell chromatin, indicating that the sequence contains conformational information that can be expressed in vivo. This view is supported by evidence that exogenously derived Hut2 pPu/pPy tracts introduced into mouse L cells and integrated in chromatin can assume an S1-sensitive conformation.
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PMID:Human homologs of TU transposon sequences: polypurine/polypyrimidine sequence elements that can alter DNA conformation in vitro and in vivo. 302 5

We have characterized the 5' end of the rat gene encoding isoform 3 of the plasma membrane Ca(2+)-ATPase using S1 nuclease protection and DNA sequence analysis. The 5'-untranslated region consists of over 900 nucleotides and includes a 217-nucleotide sequence composed of alternating tracts of TCC and ACC trinucleotides. Analysis of genomic sequences 5' to the transcription initiation site revealed potential binding sites for transcription factors that are active in muscle and brain.
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PMID:Analysis of the 5' end of the rat plasma membrane Ca(2+)-ATPase isoform 3 gene and identification of extensive trinucleotide repeat sequences in the 5' untranslated region. 854 Dec 82

Microtubule-associated protein 1B (MAP1B) is a major constituent of the neuronal cytoskeleton that is expressed at high levels during early brain development and plays a role in axonal growth and neuronal plasticity. Previous studies suggested that the regulation of its gene expression is primarily at the transcriptional level. Thus, the characterization of the promoter region should help to define regulatory elements that control neuron-specific and developmental expression of the MAP1B gene. We have isolated genomic clones containing up to 11 kb of the upstream region of the rat MAP1B gene, sequenced approximately 1.8 kb upstream from the translation start codon, and identified several consensus sequences. These sequences include a consensus element common to several neuronal genes, a TCC repeat, a cAMP response element, and two TATA boxes that were 134 nucleotides apart from each other. S1 nuclease and RNase protection assays identified two corresponding groups of transcription initiation sites that were used selectively in distinct regions of the nervous system and during different stages of development. Transient transfection assays with neuronal and non-neuronal cell lines demonstrated that each TATA sequence and its corresponding adjacent region could independently direct neuron-specific expression of a reporter gene. Furthermore, the transcription of the reporter gene was initiated from the same sites as those of the MAP1B gene in vivo. These results suggest that two alternative and overlapping promoters, one inducible and the other constitutive, regulate the temporal and tissue-specific expression of the rat MAP1B gene.
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PMID:Two alternative promoters direct neuron-specific expression of the rat microtubule-associated protein 1B gene. 875 33

Microtubule-associated protein 1B (MAP1B) is a major cytoskeletal protein expressed early during development of the nervous system. Previous analysis of the MAP1B gene has identified two alternative promoters that can independently regulate neuron-specific expression of MAP1B. To further characterize the MAP1B promoters, we performed DNase I hypersensitivity assays in vivo over a range of 8.5 kb surrounding the transcription initiation sites. These studies identified a DNase I-hypersensitive site that was present in brain but not liver nuclei at the proximal region of the MAP1B promoter, located between the two transcription initiation sites. Fine mapping by S1 nuclease sensitivity localized two adjacent sites in the proximal promoter region that contained three symmetrical inverted repeats. Electrophoresis mobility shift assays showed that proteins present in nuclear extracts can bind two consensus regulatory elements present within the proximal promoter region, Sp1 and cyclic AMP response element. In addition, there was a specific nuclear protein binding activity with two common sequences, a "neuronal motif " and a TCC repeat motif. This binding activity was much more abundant in liver than in brain nuclear extracts, suggesting that it may represent a negative control element in the tissue-specific expression of the MAP1B gene.
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PMID:Structural analysis of the proximal region of the microtubule-associated protein 1B promoter. 928 12