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)

The structure of the gene for the human alpha 1(XIII) collagen chain (COL13A1) was determined from genomic clones spanning 140,000 base pairs (bp), including about 3,000 bp of the 5'-end-flanking region and 5,000 bp of the 3'-end-flanking region. The gene was shown to contain 39 exons. There were eight exons of 27 bp, five of 36 bp, four of 54 bp, three of 45 bp, and two of 42 bp. The rest of the exons coding for translated sequences had sizes varying between 24 and 153 bp. The genomic clones did not contain exons 3 and 4 whose sizes could, however, be estimated from cDNA clones. S1 nuclease mapping and primer extension analyzes indicated five closely spaced initiation sites of transcription. Sequencing of the 5'-end-flanking region did not reveal a typical TATA box but a four times repeated TATTTAT sequence that may serve as true TATA boxes. Two CCAAT boxes were found starting at positions-13 and -194, and furthermore, the promoter region contains two GC boxes. Previous studies on alpha 1 (XIII) collagen cDNA and genomic clones showed that the primary transcript undergoes complex alternative splicing generating at least four different forms of mRNAs. The present work demonstrated that sequences of seven exons are alternatively used. These exons contain sequences coding for pure collagenous regions, pure noncollagenous regions, and an exon coding for a junction of a collagenous and noncollagenous domain.
J Biol Chem 1991 Sep 15
PMID:Human alpha 1 (XIII) collagen gene. Multiple forms of the gene transcripts are generated through complex alternative splicing of several short exons. 189 51

The cellular levels of the three translational initiation factors, IF1, IF2, and IF3, increase as a function of growth rate in parallel with those of ribosomes. Therefore both ribosomal and initiation factor gene expression is under metabolic control. To address how expression of the Escherichia coli gene for IF1, infA, is regulated, a 3-kilobase region of the genome surrounding infA was sequenced. The 5' and 3' termini of in vivo infA transcripts were defined by S1 nuclease mapping, and mRNA size was measured by Northern blot hybridization. The infA gene is transcribed by two promoters, P1 and P2, which generate transcripts of 525 and 330 nucleotides, apparently ending at the same rho-independent terminator. Analyses of operon and protein fusions to lacZ demonstrate that neither infA transcription nor translation is affected by high cellular levels of IF1. However, P2, but not P1, increases in activity as a function of the growth rate of the cell and is the dominant promoter in rich medium. Therefore, metabolic control of infA expression occurs exclusively at the level of transcription by the P2 promoter.
J Biol Chem 1991 Sep 05
PMID:Structure and expression of the infA operon encoding translational initiation factor IF1. Transcriptional control by growth rate. 190 28

The primary structure of nuclease P1, which cleaves both RNA and single-stranded DNA, from Penicillium citrinum was elucidated. The complete amino acid sequence consisting of 270 residues was determined by analysis of peptides obtained by digestion with Achromobacter protease I of the reduced and S-aminoethylated protein and by digestion with Staphylococcus aureus V8 protease of the reduced and S-carboxymethylated protein. Four half-cystine residues were assigned to Cys72-Cys217 and Cys80-Cys85. N-Glycosylated asparagine residues were identified at positions 92, 138, 184 and 197. Fast-atom-bombardment and laser-ionization MS were successfully used to confirm the determined amino acid sequences of peptides and to estimate the molecular mass of this glycoprotein having heterogenous sugar moieties, respectively. Comparison of the amino acid sequence of nuclease P1 with other nucleases revealed that the protein has a high degree of sequence identity (50%) with nuclease S1 from Aspergillus oryzae. The His-Phe-Xaa-Asp-Ala sequence (positions 60-64) is similar to the sequence (His-Phe-Asp-Ala) involving the active-site His119 of bovine pancreatic RNase A, and the Pro-Leu-His sequence (positions 124-126) is identical with the sequence involving the active-site His134 of porcine pancreatic DNase I.
Eur J Biochem 1991 Sep 15
PMID:Primary structure of nuclease P1 from Penicillium citrinum. 191 39

The human lymphocyte-specific tyrosine kinase gene, lck, is transcribed from two distinct promoters, resulting in two classes of transcripts (type I and II) differing in their 5' untranslated regions. The steady-state levels of the type I and II lck transcripts were measured in a variety of lymphoid and non-lymphoid human tumor cell lines by S1 nuclease mapping and by a sensitive assay system using the polymerase chain reaction. Human thymocytes and all the leukemic T cell lines tested express both type I and II lck transcripts, albeit at different relative levels. Peripheral blood T cells express mainly type II lck transcripts, whereas two colonic carcinoma lines, COLO 201 and COLO 205, express exclusively type I lck transcripts. Treatment of the leukemic T cell lines, P30/OKUBO and Jurkat, by the phorbol esters tetradecanoylphorbol acetate (TPA) or phorbol dibutyrate (PDB) results in the down-regulation of the type I, and the up-regulation of the type II, lck transcript levels. The effect of PDB on the in vitro differentiation of Jurkat cells, and the expression of lck transcripts, is reversible. The modulation of lck transcript levels in TPA-treated Jurkat cells is not due to differential RNA stability, suggesting that the two lck promoters are utilized differentially during T cell differentiation. The leukemic T cell line, Jurkat, may thus serve as a model for the elucidation of molecular mechanisms that regulate lck transcription and T cell differentiation.
J Cell Physiol 1991 Sep
PMID:Differential expression of two classes of lck transcripts upon phorbol ester treatment of human leukemic T cells. 191 68

In this study we cloned the 5' flanking sequence of the human c-yes gene and identified its promoter region. A 0.53 kilobase pair (kbp) fragment containing the 5' terminus of the c-yes gene showed strong promoter activity when placed upstream of the bacterial chloramphenicol acetyltransferase (CAT) gene and transfected into monkey CV-1 cells. By nuclease S1 mapping multiple transcriptional start sites were detected within the promoter region. Nucleotide sequence analysis revealed that the c-yes promoter region had high G + C contents (64%) and contained six GC box-like sequences (one at the 5' distal region and five in a cluster at the 5' proximal region), but not a TATA box. These features of the c-yes promoter region are similar to those of other protooncogenes, ras-family genes and c-raf-1, and some house-keeping genes. Deletion analysis suggested that the most downstream 0.21 kbp region is primarily important for the promoter activity. This 0.21 kbp region contains one major and another minor transcriptional start site. Five GC box-like sequences were located within this region, and four of them were shown to bind with purified Sp1 transcription factor. Furthermore, using the base-substituted mutants of the Sp1-binding sites, each GC box in the cluster (GC1 to GC4) was shown to affect the c-yes gene expression.
Oncogene 1991 Sep
PMID:Characterization of the promoter region of the c-yes proto-oncogene: the importance of the GC boxes on its promoter activity. 192 23

In order to detect the mRNA transcribed from the multidrug-resistance gene (MDR1), thymine-thymine (T-T) dimerized single-stranded DNA probes have been utilized for hybridization with mRNA either on nitrocellulose filters or in cells and tissues. S1 nuclease digestion rather than sonication was used to obtain short T-T dimerized single-stranded DNA (300-400 bases) so that they could penetrate well into the cytoplasm. The hybridized T-T DNA was detected immunohistochemically using rabbit anti-T-T DNA antibody (Ab) and peroxidase-labeled goat anti-rabbit IgG Ab. Employing this system, MDR1 mRNA could be localized clearly in the human multidrug-resistant cell lines K562/ADM, CEM/VLB, 2780AD, and KBC4 cells as well as in human fetal kidney and gastric carcinoma. Furthermore, our system successfully detected the expression of MDR1 mRNA in cell lines of increasing resistance. These results paralleled results obtained at the protein level by immunohistochemistry. The analysis of MDR1 RNA expression by this in situ hybridization technique should be useful in the study of normal human tissues and tumor samples expressing the MDR1 gene.
Jpn J Cancer Res 1990 Sep
PMID:In situ localization of the human multidrug-resistance gene mRNA using thymine-thymine dimerized single-stranded cDNA. 197 30

The rat beta-galactoside alpha 2,6-sialytransferase gene is differentially utilized by liver and kidney in the generation of mRNAs that predict substantially divergent polypeptides. In order to determine the biosynthetic relationship between these sialyltransferase mRNA isoforms, genomic sequences were isolated and analysed. Five exons that span at least 40 kb of DNA carry the coding information for the liver beta-galactoside alpha 2,6-sialyltransferase protein. An additional exon contains only sequences for the 5'-untranslated leader of the liver mRNA. In contrast, the predominant kidney mRNAs from this gene share only three coding exons that specify the carboxyl terminal 42% of the liver sialyltransferase protein sequence. In addition, these kidney mRNAs contain information from two other exons that comprise the 5' divergent region of these transcripts. Primer extension and S1 nuclease protection analysis demonstrate that the hepatic and kidney specific mRNAs are transcriptionally initiated at different sites within the sialyltransferase gene. While the hepatic sialyltransferase mRNAs are transcribed from the first exon, the kidney transcripts are initiated from a site within the third intron. Genomic regions upstream of both transcriptional initiation sites can regulate expression of the bacterial chloramphenicol acetyltransferase gene in transiently transfected L cells. Together, the data implicate multiple promoters as a principle mechanism in the generation of kidney and liver gene product diversity in sialyltransferase expression.
Glycobiology 1990 Sep
PMID:Rat beta-galactoside alpha 2,6-sialyltransferase genomic organization: alternate promoters direct the synthesis of liver and kidney transcripts. 198 83

Using an enzyme-linked immunosorbent assay (ELISA) employing two monoclonal antibodies recognizing distinct epitopes on the interleukin 2 receptor (IL2R) alpha chain (Tac molecule), we previously demonstrated that activated lymphocytes release a soluble interleukin 2 receptor molecule (sIL2R) in vitro and in vivo. The sIL2R is biochemically and structurally related to Tac, but its precise origin and functional role remain to be defined. We report here that a single IL2R cDNA is sufficient to direct the synthesis of both cell-associated and soluble released IL2R molecules. Northern analysis of IL2R cDNA transfected L-cell lines revealed the presence of mRNA species unaccounted for by known transcription termination or internal splice sites. Nevertheless, S1 nuclease digestion studies failed to detect alternately spliced mRNA transcripts that specifically lack transmembrane or cytoplasmic domains and which may encode a secreted IL2R molecule. Therefore sIL2R does not appear to be the product of a unique post-transcriptional splicing event. In the absence of any post-translational modifications, sIL2R is most likely generated by enzymatic cleavage and release of cell surface Tac. This proteolytic release of Tac may be but one example of a common cellular mechanism for regulating the membrane expression of cell surface molecules.
Cytokine 1990 Sep
PMID:The molecular basis for the generation of the human soluble interleukin 2 receptor. 210 32

The 5'-terminal region of the rat gene for the neuron-specific phosphoprotein, synapsin I, was isolated and sequenced. It comprises 1472 nucleotides (nt) of 5'-flanking sequence, 507 nt of the first exon, and 242 nt of the first intron. A single transcription start site was mapped by primer extension and S1 nuclease analysis. A sequence of 340 nt upstream from the transcription start site and the first exon are G+C-rich and enriched in CpG dinucleotides, resembling a CpG island. The 5'-flanking sequence lacks TATA and CAAT consensus elements but contains a consensus motif for the cAMP-responsive element. Furthermore, we notice two potential consensus motifs which are also found in corresponding positions in the genes for the nerve growth factor receptor and the 68-kDa neurofilament protein. The 5'-terminal region of the human synapsin I gene was also cloned and sequenced. A high degree of sequence conservation between rat and human is found in the upstream 340 nt that coincides precisely with the G+C-rich domain and includes the consensus elements, and throughout the first exon including the untranslated sequence. Sequence conservation is also observed further upstream and at the beginning of the first intron. In a transient chloramphenicol acetyltransferase expression assay, 5'-flanking sequences of the rat synapsin I gene function as strong promoters in neuroblastoma cells, but not in fibroblastoid cells. 225 nt of 5'-flanking sequence and 105 nt of 5'-untranslated sequence are sufficient for cell-type specific transcription in this assay.
J Biol Chem 1990 Sep 05
PMID:The 5'-flanking region of the synapsin I gene. A G+C-rich, TATA- and CAAT-less, phylogenetically conserved sequence with cell type-specific promoter function. 211 19

The nucleotide sequence of the 1206 bp fragment of Pseudomonas aeruginosa DNA coding for the recA gene has been determined. This structure was shown to contain an open reading frame corresponding to a protein with m.w. 36808 D highly homologous (70%) to the Escherichia coli recA protein. Homology on the DNA level is significantly lower (57%) due to the high G/C content characteristics of Pseudomonas DNA. Making use of S1 nuclease and reverse transcriptase it was shown that in P. aeruginosa and E. coli cells recAPA gene transcription starts from A or T unit. Unlike "-35" region, "-10" region is homologous to the consensus E. coli promoter sequence. Comparison of primary structures of the recAPA and recAEC proteins demonstrates that the recAPA protein is by 7 amino acid residues shorter and differs from recAEC at 108 positions. Homology is the lowest in the C-terminal part. Basing on the analysis of hybrid recAPA proteins with a modified C-terminal part, it may be suggested that C-terminus is nonessential for main activities of the recA protein.
Bioorg Khim 1990 Sep
PMID:[Structure of the Pseudomonas aeruginosa recA gene]. 212 86


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