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)

With the improved rapid sequencing techniques, the earlier sequence of U2 RNA of Novikoff hepatoma (Shibata et al, J. Biol. Chem. 250, 3909-3920, 1975) was reanalyzed and modified. The improved sequence of U2 RNA is 188 (or 189) nucleotides long and is in register with a characterized U2 RNA pseudogene (Denison et al, PNAS 78, 810-814, 1981) except for an 11 nucleotide sequence (nucleotides 147-157) which is absent from the pseudogene. From these results, a secondary structure of U2 RNA is proposed which is supported by the preferred cleavage sites with T1-RNase, RNase A and S1 nuclease. Isolated U2 RNA was cleaved by T1-RNase preferentially at positions 64 and 164, whereas U2 RNA in U2-snRNP was cleaved only at position 64, indicating that position 164 is protected in U2-snRNP. As with U1 RNA (Epstein et al, PNAS 78, 1562-1566, 1981) the 5'-end of isolated U2 RNA was not preferentially cleaved by T1-RNase.
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PMID:Primary and secondary structure of U2 snRNA. 679 40

We have analyzed the differential expression of a family of beta-like globin genes during the development of rabbits, from four days post implantation to one week before birth. The family is composed of four genes, arranged 5'-beta 4-beta 3-psi beta 2-beta 1-3' on the chromosome; psi beta 2 is an inactive pseudogene. Using the technique of hybrid-arrested translation in vitro, we have identified the embryo-specific globin polypeptides encoded by genes beta 3 and beta 4. The beta 3 and beta 4 globins are replaced by the adult beta 1 globin halfway through gestation; this corresponds temporally with the switch in site of erythropoiesis from the embryonic yolk sac to the fetal liver. The decline in production of beta 3 globin polypeptide precedes the decline in beta 4 globin. Transcripts from genes beta 1, beta 3 and beta 4 were analyzed at progressive stages of gestation by a blot-hybridization assay and by an S1 nuclease protection assay. Mature messenger RNA and presumptive precursor RNAs from genes beta 3 and beta 4 are synthesized abundantly in embryonic erythroid cells but only at very low levels later in fetal development. Conversely, precursor and mature mRNA from gene beta 1 are found at very low levels in embryos but are abundant in fetal and adult erythroid cells. The co-ordinate appearance of precursor RNA, mRNA and polypeptide from all three active genes indicates that the primary developmental regulation of this gene family is exerted at the level of transcription. RNA species larger than the expected precursors were observed when the RNA was denatured with formaldehyde but not when methylmercury was the denaturant. These large RNAs are a formaldehyde-generated artifact, possibly a result of cross-linking globin transcripts to ribosomal RNA. We observe no extensive stable transcripts from the 5' or 3' flanking regions of these genes.
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PMID:Analysis of rabbit beta-like globin gene transcripts during development. 684 97

Using a modification of the Berk and Sharp S1 nuclease mapping procedure and by analyzing actin cDNA clones, we have examined the expression of several members of the 17-member multigene family encoding actin in Dictyostelium. The mapping procedure, which takes advantage of the fact that the actin genes are homologous in the protein-coding region but are very divergent in the proposed 5' untranslated region has enabled us to quantitate the relative expression of several genes during the Dictyostelium life cycle. We have shown that at least six of the 17 potential actin-coding sequences are expressed. One is not expressed at levels of more than 0.5--1% of total actin mRNA at the developmental times examined and appears to be a pseudogene. By quantitating the amount of actin mRNA in mRNA populations isolated from cells at various times in development, we have shown that four of the actin genes show different patterns of expression. Interestingly, three of the four genes appear to encode the same protein. We have also taken advantage of the S1 mapping procedure to identify the 5' ends of the actin mRNAs from four genes and have compared the sequences outside the 5' ends on these genes with the nucleotide sequences of seven other actin genes. We have identified homologous sequences in most of these genes that may be involved in initiation of transcription.
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PMID:Differential expression and 5' end mapping of actin genes in Dictyostelium. 689 15

A human genomic clone, psi GS, containing an intron-less glutamine synthetase (GS)-encoding pseudogene, was isolated by screening a human library. A sequence of 3004 bp, containing the GS coding region and both the 5' and 3' flanking sequences, was identified that exhibits all the characteristics of a processed pseudogene. The coding region shows 93% identity with the human GS cDNA (hGS) sequence and contains two frame-shifts and two termination codons. The coding sequence is flanked by a 9-bp AT repeat and a putative polyadenylation site, AATAAA, at the 3' end. Primer extension analysis and S1 nuclease mapping showed a transcription start point (tsp) 62 bp upstream from the start codon indicating a shorter untranslated region than hGS. Transfection of HeLa cells with cat constructs containing portions of the 5' flanking sequence showed the presence of a functional promoter/enhancer within 200 bp of the tsp, independent of its orientation.
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PMID:Detection of a functional promoter/enhancer in an intron-less human gene encoding a glutamine synthetase-like enzyme. 787 83

We have isolated and characterized the gene encoding mouse synexin, which consists of 14 exons and spans approximately 30 kbp of genomic DNA. The protein's unique N-terminal domain is encoded by six exons, and the C-terminal tetrad repeat, the site of the membrane-fusion and ion-channel domain, is encoded by seven exons. The first exon encodes the 5'-untranslated region. Analysis of synexin-gene expression in different mouse tissues shows that mRNA with exon 6 is only present in brain, heart and skeletal muscle. mRNA lacking exon 6 is expressed in all tissues we have examined. The initiation site for transcription was determined by primer-extension analysis and S1 nuclease mapping. Sequence analysis of the 1.3 kb 5'-flanking region revealed that the promoter has a TATA box located at position -25 and a number of potential promoter and regulatory elements. A CCAAT motif was not observed but CCATT is located in an appropriate position for the CCAAT motif upstream from the transcription-initiation start site. In addition, the 5'-flanking region contains two sets of palindromic sequences. Finally, we have determined that the functional synexin gene (Anx7) is located on mouse chromosome 14 and that a pseudogene (Anx7-ps1) is located on chromosome 10.
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PMID:Genomic organization and chromosomal localization of the mouse synexin gene. 805 9

The chloroplast S10 ribosomal protein operon is partially duplicated in many plants because it initiates within the inverted repeat of the circular chloroplast genome. In spinach, the complete S10 operon (S10B) spans the junction between inverted repeat B (IRB) and the large single-copy (LSC) region. The S10 operon is partially duplicated in the inverted repeat A (IRA), but the sequence of S10A completely diverges from S10B at the junction of S10A and the LSC region. The DNA sequence shared by S10A and S10B includes trnI1, the rpl23 pseudogene (rpl23 psi), the intron-containing rpl2 and rps19, which is truncated in S10A at the S10A/LSC junction (rps19'). Transcription of rps19' from the promoter region of S10A could result in the synthesis of a mutant S19 protein. Analysis of RNA accumulation and run-on transcription from S10A and S10B using unique probes from the S10A/LSC and S10B/LSC junctions reveals that expression of S10A is reduced. The difference in S10A and S10B expression appears to be the result of reduced transcription from S10A, rather than differences in RNA stability. Transcription of S10B can initiate at three distinct promoter regions, P1, P2 and P3, which map closely to transcripts detected by S1 nuclease analysis. P1 is located upstream of trnI1 and has the highest transcription initiation frequency in vitro of the three promoter regions. The DNA sequence of P1 is most similar to the chloroplast promoter consensus DNA sequence. Interference by the highly and convergently transcribed psbA-trnH1 operon is considered as a mechanism to explain the reduced activity of the S10A promoters.
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PMID:Differential expression of the partially duplicated chloroplast S10 ribosomal protein operon. 823 97

In this study we characterized a genetic locus that is predicted to encode one of the three AraC-like regulators of Neisseria meningitidis, a homologue of MpeR of Neisseria gonorrhoeae which is specific to the pathogenic Neisseria species. Previous microarray studies have suggested that this gene is a member of the Fur regulon. In strain MC58, it is a pseudogene (annotated as two ORFs, NMB1879 and NMB1878) containing a frameshift mutation which we show is common to all strains tested belonging to the ST-32 hypervirulent clonal complex. Using primer extension and S1 nuclease protection assays, we mapped two promoters in the upstream intergenic region: the mpeR promoter and the NMB1880 promoter. The latter promoter drives transcription of the divergent upstream locus, which is predicted to encode a high-affinity iron uptake system. We demonstrated that both promoters are induced during iron limitation and that this regulation is also mediated by the Fur regulator. DNA-binding studies with the purified MpeR protein revealed that it binds to a region directly upstream of the NMB1880 divergent promoter, suggesting a role in its regulation. Mutants of N. meningitidis strains lacking MpeR or overexpressing MpeR showed no significant differences in expression of the P(NMB1880) promoter, nor did global transcriptional profiling of an MpeR knockout identify any deregulated genes, suggesting that the MpeR protein is inactive under the conditions used in these experiments. The presence of MpeR in a regulatory cascade downstream of the Fur master iron regulator implicates it as being expressed in the iron-limiting environment of the host, where it may in turn regulate a group of genes, including the divergent iron transport locus, in response to signals important for infection.
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PMID:Identification of the in vitro target of an iron-responsive AraC-like protein from Neisseria meningitidis that is in a regulatory cascade with Fur. 2160 19


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