51
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Umek RM, Kowalski D. The DNA unwinding element in a yeast replication origin functions independently of easily unwound sequences present elsewhere on a plasmid. Nucleic Acids Res 1990; 18:6601-5. [PMID: 2174542 PMCID: PMC332616 DOI: 10.1093/nar/18.22.6601] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We have previously identified a DNA unwinding element (DUE) in autonomously replicating sequences (ARSs) and demonstrated a correlation between single-strand-specific nuclease hypersensitivity of the DUE and ARS-mediated plasmid replication in yeast. The DUE in the H4 ARS is the most easily unwound sequence in a supercoiled DNA molecule, in the context of the Ylp5 plasmid. To determine whether sequences which are more readily unwound than the ARS can influence replication activity, we have inserted such sequences, called 'torsional sinks', into the plasmids at a site distal to the ARS. We show that the torsional sink sequences effect reduction or elimination of the nuclease hypersensitivity of a variety of H4 ARS derivatives. However, we detect no difference in the in vivo replication activity of an individual ARS plasmid with or without a torsional sink. Thus, the function of the DUE in a yeast replication origin is unaffected by easily unwound sequences present elsewhere on the same plasmid.
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52
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Singh A, Singh S, Kanungo MS. Conformation and expression of the albumin gene of young and old rats. Mol Biol Rep 1990; 14:251-4. [PMID: 1965602 DOI: 10.1007/bf00429893] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The conformation and expression of the albumin gene in the liver of young (21-) and old (85-week) rats were studied. Digestion of nuclei with MNase shows no differences in the nucleosomal organization in the coding region of the gene in the two ages. The gene has a DNase I hypersensitive site which is distinctly less sensitive in old rats. Its 5'-CCGG-3' sequences are more methylated in the old in which its rate of transcription is also lower.
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53
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Goodchild J. Conjugates of oligonucleotides and modified oligonucleotides: a review of their synthesis and properties. Bioconjug Chem 1990; 1:165-87. [PMID: 1965782 DOI: 10.1021/bc00003a001] [Citation(s) in RCA: 354] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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54
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Dixon DK, Jones D, Candido EP. The differentially expressed 16-kD heat shock genes of Caenorhabditis elegans exhibit differential changes in chromatin structure during heat shock. DNA Cell Biol 1990; 9:177-91. [PMID: 2160246 DOI: 10.1089/dna.1990.9.177] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The 16-kD heat shock genes of Caenorhabditis elegans are encoded by four highly similar genes, arranged as divergently transcribed pairs. In spite of the high level of identity that exists between the HSP16 genes, after 2 hr of heat shock the mRNA from one locus accumulates at 7-14 times the level of that from the other locus. To determine if differential HSP16 gene transcriptional activity contributes to these differences, we examined the chromatin structure of the HSP16 genes in nonshocked embryos and in embryos undergoing both the initial phases of heat shock and after 2 hr of heat shock. To carry out these studies, we developed a nuclei isolation procedure that has allowed us to prepare large amounts of nuclei from C. elegans embryos, larvae, and adults that are essentially free of endogenous nuclease and protease activities and appear to be an excellent substrate for investigating chromatin structure in C. elegans. This procedure has enabled us to report the first observations of C. elegans basic chromatin structure, as well as characterize HSP16 chromatin structure in detail. The data suggest that differential HSP16 RNA accumulation following 2 hr of heat shock appears to be correlated with a change in the chromatin structure of one of the HSP16 loci to a preinduction, transcriptionally inactive configuration.
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55
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De Simone V, Cortese R. A negative regulatory element in the promoter of the human alpha 1-antitrypsin gene. Nucleic Acids Res 1989; 17:9407-15. [PMID: 2555792 PMCID: PMC335141 DOI: 10.1093/nar/17.22.9407] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
A "minimal tissue-specific element" of the human alpha 1-antitrypsin (alpha 1-AT) gene promoter, located in the -137/-37 region, is able to drive hepatoma-specific transcription from the heterologous SV40 promoter. Here we show that, in HeLa cells, this element is inactivated by a negative regulatory mechanism. This negative control can be overcome by deletion or mutation of two specific DNA domains.
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56
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Smith GL, Chan YS, Kerr SM. Transcriptional mapping and nucleotide sequence of a vaccinia virus gene encoding a polypeptide with extensive homology to DNA ligases. Nucleic Acids Res 1989; 17:9051-62. [PMID: 2555782 PMCID: PMC335113 DOI: 10.1093/nar/17.22.9051] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Nucleotide sequencing of the vaccinia virus SalI F DNA fragment identified an open reading frame of 552 amino acids encoding a protein of 63.3 kDa. The deduced amino acid sequence shares 30% identity with S. pombe and S. cerevisiae DNA ligases, with homology strongest near the carboxy terminus and around the lysine residue required for ligase-adenylate formation. Prokaryotic DNA ligases are poorly related to the vaccinia sequence. The initiation codon of the ORF forms part of a late transcriptional initiation sequence TAAATG and is preceded by two overlapping early transcriptional termination signals, TTTTTTTAT. Nonetheless, RNA mapping showed that the ligase gene is transcribed early during infection and the 5' end of the mRNA maps to the TAAATG motif. The possible roles of a DNA ligase in vaccinia virus DNA replication and recombination are discussed.
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57
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Gallagher JE, Jackson MA, George MH, Lewtas J, Robertson IG. Differences in detection of DNA adducts in the 32P-postlabelling assay after either 1-butanol extraction or nuclease P1 treatment. Cancer Lett 1989; 45:7-12. [PMID: 2540901 DOI: 10.1016/0304-3835(89)90029-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The use of nuclease P1 treatment and 1-butanol extraction to increase the sensitivity of the 32P-postlabelling assay for DNA adducts have been compared. Although similar results were obtained with the two methods for standard adducts formed with benzo[a]pyrene diol epoxide I (BPDE-I), nuclease P1 treatment resulted in a significant reduction in detection of major adducts from 1-amino-6-nitropyrene (1-amino-6-NP), 1-amino-8-nitropyrene (1-amino-8-NP), 2-aminofluorene (2-AF), 2-naphthylamine (2-NA) and 4-aminobiphenyl (4-ABP) modified DNAs, but not following the 32P-postlabelling analysis of 2-acetylaminofluorene (2-AAF) modified DNA. These results suggest that, at least initially, both modifications of the 32P-postlabelling assay should be used for the detection of unknown adducts or for adducts derived from nitroaromatics and aromatic amines.
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58
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Freistadt MS, Cross GA, Robertson HD. Discontinuously synthesized mRNA from Trypanosoma brucei contains the highly methylated 5' cap structure, m7GpppA*A*C(2'-O)mU*A. J Biol Chem 1988; 263:15071-5. [PMID: 2844798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Trypanosoma brucei mRNA is discontinuously synthesized via the 5' addition of a "mini-exon" sequence. The mini-exon-specific cap structure was purified from a complete RNase T2 and phosphatase digest of in vivo 32P-labeled poly(A)+RNA. The purified cap structure was sequenced by a series of partial and complete enzymatic digests by nuclease P1 and venom phosphodiesterase. This approach demonstrated that the T. brucei mini-exon cap structure consists of N7-methylguanosine linked in a conventional 5'-5' triphosphate bond to five nucleotides, in the sequence A*A*C(2'-O)mU*A (asterisks denote modifications that were not fully characterized in this work). 2'-O-methylations and other modifications appear to be present in this novel cap structure, which could have a functional role in the metabolism of the mini-exon.
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59
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Schnos M, Zahn K, Inman RB, Blattner FR. Initiation protein induced helix destabilization at the lambda origin: a prepriming step in DNA replication. Cell 1988; 52:385-95. [PMID: 2830983 DOI: 10.1016/s0092-8674(88)80031-x] [Citation(s) in RCA: 130] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The interaction of the lambda phage initiator protein, O, with the lambda origin sequence, ori, has been investigated. Binding of O, or its amino-terminal fragment, causes a major structural change within a 60 bp AT-rich region just to the right of the O-binding site. ATP or other molecular energy sources are not required. The modification, as assayed by nuclease sensitivity, is reduced when certain ori mutant sequences, which bind O but fail to replicate, are substituted for the wild-type sequence. The modification of DNA structure caused by the interaction of O is absolutely dependent on the presence of superhelical tension at the lambda origin sequence, and has several properties consistent with a strand separation reaction. We propose that this modification is a fundamental prepriming event that is the first stage in initiation of bidirectional replication in lambda after O binding.
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60
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Ward CD, Stokes MA, Flanegan JB. Direct measurement of the poliovirus RNA polymerase error frequency in vitro. J Virol 1988; 62:558-62. [PMID: 2826815 PMCID: PMC250568 DOI: 10.1128/jvi.62.2.558-562.1988] [Citation(s) in RCA: 98] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The fidelity of RNA replication by the poliovirus-RNA-dependent RNA polymerase was examined by copying homopolymeric RNA templates in vitro. The poliovirus RNA polymerase was extensively purified and used to copy poly(A), poly(C), or poly(I) templates with equimolar concentrations of noncomplementary and complementary ribonucleotides. The error frequency was expressed as the amount of a noncomplementary nucleotide incorporated divided by the total amount of complementary and noncomplementary nucleotide incorporated. The polymerase error frequencies were very high and ranged from 7 x 10(-4) to 5.4 x 10(-3), depending on the specific reaction conditions. There were no significant differences among the error frequencies obtained with different noncomplementary nucleotide substrates on a given template or between the values determined on two different templates for a specific noncomplementary substrate. The activity of the polymerase on poly(U) and poly(G) was too low to measure error frequencies on these templates. A fivefold increase in the error frequency was observed when the reaction conditions were changed from 3.0 mM Mg2+ (pH 7.0) to 7.0 mM Mg2+ (pH 8.0). This increase in the error frequency correlates with an eightfold increase in the elongation rate that was observed under the same conditions in a previous study.
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61
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Randerath E, Mittal D, Randerath K. Tissue distribution of covalent DNA damage in mice treated dermally with cigarette 'tar': preference for lung and heart DNA. Carcinogenesis 1988; 9:75-80. [PMID: 2826034 DOI: 10.1093/carcin/9.1.75] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The high incidence of lung cancer in smokers is thought to be related to the direct exposure of bronchial and pulmonary cells to carcinogens in inhaled cigarette smoke. Using a 32P-postlabeling assay for chemically induced covalent DNA alterations, we found that unfractionated, relatively non-polar cigarette smoke components bound preferentially to lung and heart DNA in female ICR mice. After 6 days of topical treatment with cigarette smoke condensate (CSC) equivalent to a total of 4.5 cigarettes, covalent DNA damages was estimated to be 6.2, 5.7, 3.9 and 1.9 times higher, respectively, in lung, heart, skin and kidney than in liver, ranging from approximately 1 adduct in 5.4 +/- 0.7 X 10(6) DNA nucleotides in lung to 1 adduct in 3.3 +/- 0.6 X 10(7) DNA nucleotides in liver. Spleen DNA was virtually adduct-free. Adducts occupied two extensive zones, designated diagonal radioactive zone (DRZ) 1 and DRZ 2, on TLC fingerprints. Preference for lung and heart DNA was also observed in mice treated for 1 or 3 days. An inverse association appeared to exist between the tissue distribution of CSC-induced covalent DNA damage and the reported activity of enzymes catalyzing the metabolism of xenobiotics (cytochrome P-450 monooxygenases, phase II enzymes) and toxic oxygen species (superoxide dismutase, catalase). The results suggest that the well-known pulmonary and cardiovascular organotropism of cigarette-smoking-associated adverse health effects may, in part, have its origin in the inherent capacity of cigarette smoke components to induce lesions in lung and heart DNA in a tissue-specific manner. Possible mechanisms and health implications of the preferential binding of presumably aromatic CSC constituents to lung and heart DNA are discussed.
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62
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Ueno S, Ueck M. Cyclic nucleotide phosphodiesterase activity: histochemical and cytochemical methods. Methods Enzymol 1988; 159:477-89. [PMID: 2842613 DOI: 10.1016/0076-6879(88)59047-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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63
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Reddy MV, Randerath K. 32P-postlabeling assay for carcinogen-DNA adducts: nuclease P1-mediated enhancement of its sensitivity and applications. ENVIRONMENTAL HEALTH PERSPECTIVES 1987; 76:41-47. [PMID: 2834194 PMCID: PMC1474489 DOI: 10.1289/ehp.877641] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Exceedingly sensitive assays are required for the detection of DNA adducts formed in humans exposed to low levels of environmental genotoxicants and therapeutic drugs. A 32P-postlabeling procedure for detection and quantitation of aromatic carcinogen-DNA lesions with a sensitivity limit of 1 adduct in 10(7) to 10(8) nucleotides has been described previously. In the standard procedure, DNA is enzymatically digested to 3'-phosphorylated normal and adducted mononucleotides, which are 32P-labeled at 5'-hydroxyl groups by T4 polynucleotide kinase-catalyzed [32P]phosphate transfer from [gamma-32P]ATP. 32P-labeled derivatives are resolved by TLC, detected by autoradiography, and quantitated by counting. This assay has been recently utilized for the determination and partial characterization of DNA adducts formed in somatic and reproductive tissues of rats given the clinically used anticancer drug, mitomycin C. The drug exhibits similar levels of covalent binding to DNA in most tissues. Further studies have revealed that adducted nucleotides are primarily guanine derivatives that are resistant to 3'-dephosphorylation by Penicillium citrinum nuclease P1. The latter observation has been utilized to enhance the 32P-assay's sensitivity to 1 adduct in 10(10) nucleotides for a 10-micrograms DNA sample by postincubation of DNA digests with nuclease P1 before 32P-labeling. The enzyme dephosphorylates the normal nucleotides but not most aromatic and bulky nonaromatic adducts, so that only the latter serve as substrates for the kinase-catalyzed labeling reaction. The new assay has also shown utility in the analysis of very low levels of age- and tissue-related DNA modifications, which might arise from dietary or endogenous compounds, in untreated rats and in humans.
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64
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Endo Y, Tsurugi K. RNA N-glycosidase activity of ricin A-chain. Mechanism of action of the toxic lectin ricin on eukaryotic ribosomes. J Biol Chem 1987; 262:8128-30. [PMID: 3036799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The modification reaction of 28 S rRNA in eukaryotic ribosomes by ricin A-chain was characterized. To examine whether ricin A-chain release any bases from 28 S rRNA, rat liver ribosomes were incubated with a catalytic amount of the toxin, and a fraction containing free bases and nucleosides was prepared from the postribosomal fraction of the reaction mixture by means of ion-exchange column chromatography. Thin-layer chromatographic analysis of this fraction revealed a release of 1 mol of adenine from 1 mol of ribosome. When the ribosomes or naked total RNAs were treated with ricin A-chain in the presence of [32P] phosphate, little incorporation of the radioactivity into 28 S rRNA was observed, indicating that the release is not mediated by phosphorolysis. Thus, considering together with the previous result (Endo, Y., Mitsui, K., Motizuki, M., and Tsurugi, K. (1987) J. Biol. Chem. 262, 5908-5912), the results in the present experiments demonstrated that ricin A-chain inactivates the ribosomes by cleaving the N-glycosidic bond of A4324 of 28 S rRNA in a hydrolytic fashion.
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65
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Baumann U, Frank R, Blöcker H. Conformational analysis of hairpin oligodeoxyribonucleotides by a single-strand-specific nuclease. EUROPEAN JOURNAL OF BIOCHEMISTRY 1986; 161:409-13. [PMID: 3023095 DOI: 10.1111/j.1432-1033.1986.tb10460.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Hairpin-forming oligodeoxynucleotides d[ATCCTA(A)NTAGGAT] with n = 3-6 were subjected to nuclease digestion with the nuclease from mung bean. Cleavage occurs only in the loop region of the hairpin molecules. In detail, the number and intensity of cleavage sites were determined in relation to the length of the loop, the temperature and the salt concentration. The restricted accessibility of mung bean nuclease to the loop bases adjacent to the helical region of all hairpins is due to a reduced exposure of these bases in presence of a certain Mg2+ concentration. With increasing temperature the exposure of these bases is increased. It is deduced that the bases adjacent to the helix increase the length of the latter by stacking, the degree of which is dependent on the number of loop bases.
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66
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Goldsmith ME, Beckman CA, Cowan KH. 5' Nucleotide sequences influence serum-modulated expression of a human dihydrofolate reductase minigene. Mol Cell Biol 1986; 6:878-86. [PMID: 3022136 PMCID: PMC367588 DOI: 10.1128/mcb.6.3.878-886.1986] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Human dihydrofolate reductase (DHFR) gene sequences were isolated from DHFR gene-amplified breast cancer cell line MCF-7. These genomic sequences plus human DHFR cDNA sequences were used to construct a DHFR minigene. Calcium phosphate-mediated transfer of minigene DNA into DHFR gene-deleted Chinese hamster ovary cells converted these cells to a DHFR+ phenotype at a frequency of 0.12%. Minigene-transfected cells contained 20 to 30 minigene copies per cell and had DHFR enzyme levels similar to those of wild-type MCF-7 human cells (1.4 pmol/mg of protein). In contrast to gene-amplified MCF-7 cells, which contained multiple DHFR mRNA species (1.1, 1.6, 3.8, and 5.3 kilobases), only a single 3.8-kilobase DHFR mRNA was found in minigene-transfected cells. Previous studies on normal cells demonstrated modulation of DHFR levels by a variety of conditions which altered cell growth. When cell growth was induced in minigene-transfected cells by release from serum deprivation and DHFR levels were assayed at the time of maximum DNA synthesis, these levels were increased 2.4 to 3.7-fold. In contrast, the DHFR levels in cells transfected with a construct made from DHFR cDNA and viral promoter, intron, and termination sequences were unchanged. Minigene deletions were made and analyzed to determine the DHFR gene sequences responsible for regulation. Deletion of sequences upstream from 322 base pairs 5' to the start of transcription or 90 base pairs downstream from the termination of translation (which removed most of the 3' nontranslated region of the gene) did not alter the responsiveness of minigene-transfected cells to serum deprivation. However, when sequences between 322 and 113 base pairs 5' to the start of transcription were deleted, serum-dependent expression in minigene-transfected cells was affected.
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67
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Maguire GA. Elimination of the "chromogen oxidase" activity of bilirubin oxidase added to obviate bilirubin interference in hydrogen peroxide/peroxidase detecting systems. Clin Chem 1985; 31:2007-8. [PMID: 2998643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The use of bilirubin oxidase to remove interference by bilirubin in hydrogen peroxide/peroxidase detecting systems is hampered by its inherent "chromogen oxidase" activity (its ability to oxidize the chromogens used in the systems). This unwanted activity is greater than 99% inhibited by 0.5 mmol/L cyanide, 97% inhibited by 20 mmol/L azide. At these same concentrations, they inhibit bilirubin oxidase activity by 95% and 73%, respectively. Sequential addition of reagents allows the use of bilirubin oxidase without interference by the chromogen oxidase activity.
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68
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Kuninaka A. [Nuclease P1]. TANPAKUSHITSU KAKUSAN KOSO. PROTEIN, NUCLEIC ACID, ENZYME 1985; 30:1253-6. [PMID: 3001828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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69
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Hsieh WT. Utilization of glutamate accumulating bacterial cells for production of ribonucleotides. PROCEEDINGS OF THE NATIONAL SCIENCE COUNCIL, REPUBLIC OF CHINA. PART B, LIFE SCIENCES 1985; 9:70-3. [PMID: 3033725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Corynebacterium glutamicum cells are industrially used for glutamate production. However, the waste that contains microbial cells, cellular debris, residual sugars, ammonia and metabolites seriously pollutes the environment. The cells are recovered and utilized for ribonucleotide production so that the pollution caused by the cells is eliminated. Nucleic acid is extracted from the cells and is hydrolyzed with nuclease P1 from Penicillium citrinum. The hydrolysate is fractionated with Dowex-50 and Dowex-1 into 5'-CMP, 5'-UMP, 5'-GMP and 5'-AMP. The products are characterized by electrophoresis, ultraviolet light absorbance, and 5'-nucleotidase.
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70
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Sertic-Pritsos K, Vinocour M, Winicov I. 5'-Hydroxyl RNA kinase from mouse L cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 1984; 144:47-55. [PMID: 6090142 DOI: 10.1111/j.1432-1033.1984.tb08429.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A 5'-hydroxyl RNA kinase from mouse L cells has been partially purified and characterized. The enzyme transfers the gamma-phosphorus from ATP to 5'-hydroxyl termini of RNA much more efficiently than DNA substrates, and is virtually inactive on 3'-CMP. The molecular mass of the predominant kinase activity is estimated to be 93-96 kDa from denaturing and non-denaturing polyacrylamide gel analyses. A minor band of lower molecular mass has been also observed. The enzyme activity requires Mg2+ and is inhibited by both Mn2+ and Zn2+. Antibodies to small nuclear ribonucleoproteins have no effect on this activity.
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71
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El-Shammaa NA, Fishbein WN, Armbrustmacher VW. Interstitial 5'-nucleotidase stain for frozen biopsy specimens of skeletal muscle. A useful adjunct in the diagnosis of polymyositis. Arch Pathol Lab Med 1984; 108:251-6. [PMID: 6199001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
We applied a simple lead salt-based stain for interstitial and vascular 5'-nucleotidase to 150 muscle biopsy specimens. No reaction was obtained with 2'- or 3'-adenosine monophosphate, indicating that the stain was specific, and distinct from phosphatases. Staining was not inhibited by alpha, beta-methylene adenosine 5'-diphosphate, but was prevented by formaldehyde fixation or by brief immersion in octoxynol 9 (Triton X-100). Nucleotidase stains the following specific histologic sites that distinguish it from alkaline phosphatase: the intima and adventitia of medium-sized and large arteries, perineural and muscle spindle sheaths, and tendon insertions. Aside from these structures, normal muscle shows little reaction, as the sarcoplasm and sarcolemma do not stain. Neither of these enzymes shows a compensatory increase, histochemically, in myo-adenylate deaminase deficiency. In Duchenne's muscular dystrophy, however, and particularly in inflammatory myopathy, interstitial staining of 5'-nucleotidase is increased, leading to investment of most muscle fibers in the affected area. The stain rarely identifies regenerating fibers. Although alkaline phosphatase commonly shows a corresponding increase in interstitial staining, we encountered six cases of inflammatory myopathy in which this was absent, despite pronounced endomysial staining in the 5'-nucleotidase reaction. 5'-Nucleotidase thus appears to provide a valuable adjunct in the diagnosis of inflammatory myopathy.
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72
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Goel NS, Rouyanian B, Sanati M. On the computation of the tertiary structure of globular proteins. III. Inter-residue distances and computed structures. J Theor Biol 1982; 99:705-57. [PMID: 6306353 DOI: 10.1016/0022-5193(82)90195-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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73
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Bochner BR, Ames BN. Complete analysis of cellular nucleotides by two-dimensional thin layer chromatography. J Biol Chem 1982; 257:9759-69. [PMID: 6286632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
We describe methods for the complete analysis of cellular nucleotides from as few as 10(6) 32Pi-labeled cells in a simple 2-day experiment. Nucleotides are extracted with acid, neutralized, and resolved by two-dimensional thin layer chromatography on polyethyleneimine cellulose. In the first dimension the nucleotides are separated based on the negative charge of their phosphate groups (i.e. cyclic, mono-, di, and triphosphates) and in the second dimension on their content of nucleobases (i.e. Ura, Cyt, Thy, Gua, and Ade). Because the separation is logical, one can predict the chromatographic migration of most nucleotides. By running standards we have determined the chromatographic location of over 90 biologically important nucleotides, nucleotide derivatives, and modified nucleotides from tRNA. We also developed a set of enzymatic and chemical methods to be used in conjunction with the chromatographic separations for verifying the identity of nucleotides and characterizing novel nucleotides. In this paper we use these methods to analyze and inventory the nucleotide content of Salmonella typhimurium in balanced log phase growth. Other potential uses of the method are also described.
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74
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Nagasawa K, Chechik BE, Gelfand EW, Sengupta S, Letarte M, Mak TW. Modulation of human T-cell differentiation markers by 12-O-tetradecanoylphorbol-13-acetate. THYMUS 1981; 3:307-18. [PMID: 6274066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The analysis of seven differentiation markers following incubation with the tumor promotor 12-O-tetradecanoylphorbol-13-acetate (TPA) was examined in the human leukemic T-cell line MOLT-3. Significant changes were observed in the activity of the markers terminal deoxynucleotidyl transferase (TdT). spontaneous proliferation and the ability of these cells to bind sheep erythrocytes. Levels of human thymus-leukemia-associated antigen (HThy-L) recently identified as a low molecular weight form of adenosine deaminase (ADA), were reduced by about 50%. No significant changes were observed in ecto-5'-nucleotidase [5'-NT) activities, in the proliferative response to PHA, or in the expression of IA-like antigens. These data and the time kinetics of the changes suggest that following incubation of these T-lymphoblasts with TPA there is a sequential loss of TdT, loss of the capacity for spontaneous proliferation, and the appearance of receptors for sheep erythrocytes. Subsequently there is a decrease in the level of HThy-L/ADA. This sequence appears to follow that proposed for prethymic precursor T-cell differentiation following activation with thymic epithelium.
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Shichi H, Somers RL. Distribution of enzymes involved in nucleotide metabolism in the disk and other membranes. Photochem Photobiol 1980; 32:491-5. [PMID: 6109341 DOI: 10.1111/j.1751-1097.1980.tb03793.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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