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:3.1.30.1 (S1 nuclease)
3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adenovirus type 2 or lambda DNA was digested with the pH 4.0 endonuclease, purified from adenovirus 2-infected KB cells. The enzyme produces a limit digest of approximate size in the range of 140-210 base pairs long. The termini of the DNA fragments generated by the endonuclease digestion had 3'-P and 5'-OH groups. The 3' and 5' end groups of the products were analyzed. Our data indicate that 3' end group was a purine (68-76%), dA occuring about twice the frequency of dG. The 5' end group was either dG or dC with equal frequency. Data obtained by treatment of the 5' labeled endonuclease product of lambda DNA with single-strand specific S1 nuclease from Asperigillus oryzae or exonuclease VII from Escherichia coli indicated that the majority of the products had a short 5' protruding ends. The mode of cleavage of this endonuclease seems to be through initial formation of several single-strand breaks with some base specificity. If these breaks are at close proximity on opposite strands, double-stranded fragments with protruding ends are generated.
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PMID:Specificity and mode of cleavage of the pH 4.0 endonuclease from adenovirus type 2 - infected KB cells. 4 Feb 9

Adenovirus 40 (Ad40) is defective for growth in tissue culture but is complemented when the Ad2/5 or Ad12 E1B 55K protein is supplied in trans. Ad40 E1B mRNA has not been detected in E1-transformed cells, or at early times in lytically infected cells. In cells constitutively expressing the E1B region of Ad2, Ad40 E1B mRNAs are detected at late times in infection, after the onset of DNA replication. We have determined the Ad40 E1B transcription map from RNA produced at late times in infected KB16 cells, using S1 nuclease, primer extension, PCR-cDNA analysis, and Northern blotting. E1B transcripts corresponding to Ad2 14 S, 22 S, and 9 S mRNAs were identified but no 13 S mRNA equivalent was detected, a pattern similar to that seen in the Ad12 transcription map. The coding potential for E1B 19K, 55K, and 15K proteins and for ppIX is retained in the Ad40 transcripts. In addition we find novel E1A-E1B cotranscript counterparts of the 14 S and 22 S mRNAs. These contain the first 40 codons of the E1A first exon linked to a site 4-5 nt downstream of the E1B cap site, retaining all the coding potential of the E1B mRNAs. No new open reading frames are created by the junction, and the E1A ORF terminates with one codon added after the junction. Each E1A-E1B cotranscript is present in abundance comparable to that of its authentic E1B counterpart. The E1A-E1B junction is unusual in that it does not conform to splice consensus sequences and thus may not be generated by a conventional splicing mechanism.
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PMID:Enteric adenovirus type 40:E1B transcription map and identification of novel E1A-E1B cotranscripts in lytically infected cells. 182 50

Adenovirus early region 1A (E1A), which gives rise to three overlapping transcripts, was inserted into a murine leukemia virus-derived vector, and recombinant viruses were used to prepare permanent cell lines of NIH 3T3 cells containing DNA copies of the individual 13S, 12S, and 9S mRNAs. Integrated proviral copies of the recombinant genomes were rescued as bacterial plasmids from each of the cell lines, and the DNA sequence of E1A was demonstrated to be a precise copy of the individual transcripts. The DNA copies were shown to be expressed as part of the full-length retroviral transcript by S1 nuclease analysis, and the synthesis of their encoded polypeptides was demonstrated by immunoprecipitation. Those cell lines expressing the polypeptide encoded by the 13S transcript were shown to contain that function required for regulating the accumulation of mRNAs from adenovirus early genes by their ability to complement the adenovirus type 5 E1A deletion mutant dl312. Cell lines expressing polypeptides encoded by the 13S, 12S, and 9S transcripts showed characteristic alterations in morphology. Two-dimensional gel electrophoresis of total cellular protein derived from the three cell lines demonstrated that each E1A gene product elicits specific alterations in the patterns of proteins expressed. Studies of the expression of two specific genes, those encoding fibronectin and collagen type 1, indicated that the observed alteration in levels of the two proteins results from a reduction in RNA levels induced by E1A functions.
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PMID:Individual adenovirus type 5 early region 1A gene products elicit distinct alterations of cellular morphology and gene expression. 405 56

This paper describes experiments to test the ability of a number of viruses of the Herpes group, and also Adenovirus-2 and SV40, to activate transcription from the Herpes simplex virus-1 glycoprotein D and the rabbit beta-globin promoters. Plasmids containing these genes were transfected into HeLa cells which were then infected with various viruses. Transcriptional activation in trans of the plasmid-borne promoters was monitored by quantitative S1 nuclease analysis of total cytoplasmic RNA isolated after infection. The results showed that Herpes simplex viruses 1 and 2, Pseudorabies virus, Variella Zoster virus, Human Cytomegalovirus, Equine herpes virus-1 and Adenovirus-2 activate transcription from both promoters tested. In contrast, SV40 did not activate transcription in trans in this assay. The possible mechanisms of this activation are discussed.
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PMID:Trans activation of plasmid-borne promoters by adenovirus and several herpes group viruses. 608 5

An in vitro system for accurate transcription initiation by RNA polymerase II was developed using Ehrlich ascites tumor cells. Truncated DNA containing adenovirus 2 major late promoter was faithfully transcribed in this lysate, although the efficiency of transcription was lower than that in a HeLa cell lysate. Creatinephosphate greatly enhanced accurate transcription in this lysate. The transcriptions of various truncated mouse genes containing promoter regions in this lysate were tested, but the syntheses of run-off products were not clearly detected. Adenovirus 2 major late promoter was utilized more efficiently when integrated into circular plasmid DNA than when integrated into truncated DNA, as shown by S1 nuclease analysis.
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PMID:Accurate transcription initiation in an Ehrlich ascites tumor cell lysate. 609 90

Adenovirus type 7 (Ad7) early region 1 mRNA species transcribed in rat cell lines transformed by the HindIII-I . J fragment (the left 7.8% of the viral genome) and in human KB cells infected with Ad7 were mapped on the viral genome, using S1 nuclease gel and diazobenzyloxymethyl paper hybridization techniques. At the early stage of productive infection, two mRNA's (950 and 840 nucleotides long) with the common 5' and 3' ends but different internal splicings were mapped from region 1A (map units 1.4 to 4.3), and one mRNA (2,310 nucleotides long, with the internal splicing between map units 9.9 to 10.1) was mapped from region 1B (map units 4.6 to 11.4). At the late stage, these early spliced mRNA's were also found and at least three additional Ad7 mRNA's were identified: 700-nucleotide-long mRNA in region 1A; and 1,100- and nucleotide-long mRNA's in region 1B. In transformed rat cell lines, two early region 1A mRNA's (950 and 840 nucleotides long) were also transcribed. Surprisingly, in addition, several unique Ad7 mRNA's, not found in productivity infected cells, were identified in all of the transformed cell lines. Their molecular sizes and coding sequences varied in individual cell lines. However, these mRNA's had the 5' end-proximal portion in region 1B and the 3' end-proximal portion in region 1A, these portions being transcribed by extending from region 1B to 1A on viral DNA fragments joined in a tandem array in transformed cells.
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PMID:Unique species of mRNA from adenovirus type 7 early region 1 in cells transformed by adenovirus type 7 DNA fragment. 625 60

Adenovirus-associated virus type 2 synthesizes four prominent viral transcripts, containing 4.3, 3.6, 2.6, and 2.3 kilobases (kb), in productively infected human KB cells (coinfected with adenovirus type 2). All species are polyadenylated and present in both nuclear and whole-cell RNA preparations, but only the predominant 2.3-kb (and possibly the 2.6-kb) RNA species are found on polysomes. Electrophoretic analyses under denaturing conditions of S1 nuclease-generated and exonuclease VII-generated DNA-RNA hybrids revealed, in each case, four protected DNA fragments which are equal in length (within 50 to 100 nucleotides) to the four S1 nuclease-generated hybrids resolved by electrophoresis under nondenaturing conditions. These results suggest that in the infected cell, abundant adenovirus-associated virus type 2 transcripts are present predominantly (by mass) as unspliced RNAs or, alternatively, they are spliced but contain very short (less than or equal to 50 nucleotides) leader sequences. That the 2.3-kb RNA represents such a spliced transcript is suggested by exonuclease VII mapping experiments and our more detailed RNA mapping studies (M. R. Green and R. G. Roeder, J. Virol., in press).
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PMID:Transcripts of the adenovirus-associated virus genome: multiple polyadenylated RNAs including a potential primary transcript. 625 94

Adenovirus type 5 (Ad5) mRNAs present in cells transformed with left-terminal Ad5 DNA fragments (XhoI-C, 0 to 15.5%; HindIII-G, 0 to 7.7%; HpaI-E, 0 to 4.3% were characterized by 'Northern blotting' and S1 nuclease analysis. They were compared with the mRNAs transcribed from the Ad5 E1 region in the early and late stages of lytic infection. It is shown that in XhoI-C-transformed cells the same mRNAs were transcribed as early during lytic infection: two co-terminal mRNAs from region E1a, differing only in their splicing, and one major E1b transcript. In HindIII-G-transformed cells additional E1a mRNAs were detected with a novel 5' terminus, but with the normal splicing pattern. Instead of the normal E1b mRNA, HindIII-G-transformed cells were found to contain mRNAs consisting of a viral E1b segment and a non-viral segment. This E1b-encoded segment was shown not to be involved in RNA splicing. The mRNAs in cells transformed with Ad5 HpaI-E were similar to the E1a mRNAs found in XhoI-C- and HindIII-G-transformed, and in lytically infected cells but had aberrant 3' termini. These results are discussed in the light of the Ad5 E1 DNA and RNA sequences, and protein mapping data.
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PMID:Analysis of virus-specific mRNAs present in cells transformed with restriction fragments of adenovirus type 5 DNA. 630 9

We have investigated the requirement for sequences located upstream from the TATA box for efficient transcription from the Adenovirus-2 (Ad2) E1A promoter. A series of deletions located within the E1A promoter upstream sequences were introduced into recombinants which contain or do not contain the E1A structural sequences. The amount of E1A-specific RNA produced after transfection into HeLa cells was determined by quantitative S1 nuclease analysis. We demonstrate that sequences located more than 231 bp upstream from the E1A capsite are required for efficient transcription from the E1A promoter. However, the requirement for these stimulatory sequences is less pronounced in recombinants which contain the E1A structural sequences than in those in which these sequences have been deleted. We demonstrate also that these Ad2 stimulatory sequences activate transcription in cis when inserted upstream from the heterologous -34 to +33 Ad2 major late promoter (Ad2MLP) element which is otherwise inactive when transfected into HeLa cells. These results suggest that the 270 bp Ad2 left-terminal segment contains an enhancer-like element.
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PMID:Far upstream sequences are required for efficient transcription from the adenovirus-2 E1A transcription unit. 632 98

Adenovirus 12 mRNA's transcribed from the transforming region were analyzed and mapped on viral DNA by the nuclease S1 gel and diazobenzyloxymethyl paper blot techniques in cells transformed of adenovirus 12 DNA and in cells early and late after lytic infection with adenovirus 12. Two initiation sites of mRNA transcription and two kinds of splicing were found in each of early regions 1A and 1B. For early region 1A mRNA's, four species were found in lytically infected cells. Three of them were commonly found in cells transformed by either HindIII-G or EcoRI-C. Cells transformed by HindIII-G contained two additional 1A transcripts, which could be the 3' portions of chimeric mRNA's of cellular-viral or viral-viral sequences. Transcription in the 1B region diverged among the above cell lines. Early after lytic infection, no appreciable amount of 1B mRNA was detected, whereas two species of mRNA's, one corresponding to protein IX mRNA and another having splicing, were found at the late stage. In cells transformed by EcoRI-C, a distinct mRNA species with splicing was observed. Cells transformed by HindIII-G contained a transcript from the leftmost part of the 1B sequence at the 5' portion of chimeric mRNA species, suggesting the presence of tandem integration of viral DNA in the cells. Other mRNA species in the 1A and 1B regions were also detected in both transformed cell lines. The results are discussed in relation to the nucleotide sequence of the HindIII-G fragment of adenovirus 12 DNA.
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PMID:Mapping of adenovirus 12 mRNA's transcribed from the transforming region. 746 54


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