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:3.1.27.1 (RNase)
16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ribonuclease-resistant ribonucleic acid (RNA) was isolated from uridine-labeled cultures of rabbit kidney, chicken embryo, and HeLa cells. This RNA, regardless of its source, was found to induce interference with virus growth in either rabbit kidney or chicken embryo cultures. Nuclease-treated cellular nucleic acids exhibited interference-inducing activity which eluted with a small fraction of RNA in the exclusion volume of a 6% agarose gel column. Besides resistance to ribonucleases, the interference inducer and RNA isolated from partially digested nucleic acids have in common two properties of double-stranded RNA: (i) similar sharp melting profiles were obtained for inducer and ribonuclease-resistant RNA, with T(m) dependent on NaCl concentration; (ii) ribonuclease-resistant inducer and RNA banded together in Cs(2)SO(4) density gradients at a density characteristic of known double-stranded RNA. After melting at low ionic strength, the labeled RNA shifted to a higher density and its capacity to inhibit virus replication was lost. Velocity sedimentation analysis of the cellular ribonuclease-resistant RNA indicated that the majority sedimented between 7 and 11S, but only RNA sedimenting at >==8 to 20S had a high specific activity of interference induction. Without prior ribonuclease treatment, the ribonuclease-resistant RNA can be precipitated with 2 m LiCl and thus appears to exist in purified cellular nucleic acids as part of molecular complexes with both single- and double-stranded regions of RNA. The biosynthesis of cellular double-stranded RNA is inhibited by actinomycin D.
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PMID:Virus interference by cellular double-stranded ribonucleic acid. 432 82

Large plaque (4LP) and small plaque (4SP) variants were derived from a parent bovine virus strain by serial plaque passage. Both 4LP and 4SP were resistant to chloroform and stabilized at 50 degrees C for one hour by 1.0 M magnesium chloride. Both 4LP and 4SP had buoyant densities in cesium chloride of 1.36 gm/ml. Antigenically, 4LP and 4SP were reciprocally cross neutralizable. The nucleic acid of 4LP was shown to be ribonucleic acid (RNA) by resistance of its infectivity to deoxynuclease (DNase) but not ribonuclease (RNase) and by increased incorporation of [(3)H]-uridine into cytoplasmic RNA in cells of virus infected cultures. In growth characteristics, both 4LP and 4SP had maximum adsorption times of 75 to 90 minutes but 4LP had more rapid replication and release rates and yielded nearly twice as many infectious units per cell as 4SP. The differences in growth properties correlated directly with the differential in plaque diameter which was 40-50%.
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PMID:Physical, chemical and biological characteristics of two bovine enterovirus plaque variants. 434 Mar 47

Rapidly labeled RNA was extracted from monkey cells after infection with Simian Virus 40 (SV40) and exposure to short pulses of [5-(3)H]uridine late in infection. When this RNA was self-annealed, it became resistant to digestion with ribonuclease. The fraction of RNA that resisted the ribonuclease treatment decreased with increased labeling time, or when a short pulse of radioactivity was followed by incubation with unlabeled uridine and actinomycin D. The RNase-resistant RNA was isolated by chromatography on Sephadex G-100 and shown to be double-stranded by its susceptibility to ribonuclease as a function of salt concentration and temperature. This behavior was not due to RNA-DNA hybrid formation, since deoxyribonuclease had no effect upon the double-stranded molecules, even after their denaturation. The relation of the double-stranded RNA to SV40 was demonstrated by the hybridization of about 50% (corrected value, >90%) of the separated RNA strands with component I of SV40 DNA from plaque-purified virus. After self-annealing in formamide at low temperature, about 10% of the rapidly labeled, viral RNA sedimented at 13 S. This value corresponds in size to about 60% of the SV40 DNA.These observations indicate that late in infection of monkey cells, SV40 DNA is transcribed symmetrically over a considerable portion of its length, and that subsequently some sequences from one or both of the RNA strands are degraded.
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PMID:Extensive symmetrical transcription of Simian Virus 40 DNA in virus-yielding cells. 434 93

A sensitive and quantitative nucleic acid hybridization assay for the detection of radioactively labeled avian tumor virus-specific RNA in infected chicken cells has been developed. In our experiments we made use of the fact that DNA synthesized by virions of avian myeloblastosis virus in the presence of actinomycin D (AMV DNA) is complementary to at least 35% of the sequences of 70S RNA from the Schmidt-Ruppin strain (SRV) of Rous sarcoma virus. Annealing of radioactive RNA (either SRV RNA or RNA extensively purified from SRV-infected chicken cells) with AMV DNA followed by ribonuclease digestion and Sephadex chromatography yielded products which were characterized as avian tumor virus-specific RNA-DNA hybrids by hybridization competition with unlabeled 70S AMV RNA, equilibrium density-gradient centrifugation in Cs(2)SO(4) gradients, and by analysis of their ribonucleotide composition. The amount of viral RNA synthesized during pulse labeling with (3)H-uridine could be quantitated by the addition of an internal standard consisting of (32)P-labeled SRV RNA prior to purification and hybridization. This quantitative assay was used to determine that, in SRV-infected chicken cells labeled for increasing lengths of time with (3)H-uridine, labeled viral RNA appeared first in a nuclear fraction, then in a cytoplasmic fraction, and still later in mature virions. This observation is consistent with the hypothesis that RNA tumor virus RNA is synthesized in the nucleus of infected cells.
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PMID:Quantitative determination and location of newly synthesized virus-specific ribonucleic acid in chicken cells infected with Rous sarcoma virus. 435 Jul 19

A procedure has been developed for the determination of the weight of animal RNA virus genomes using controlled nuclease digestions and computation of the moles of oligonucleotides obtained from 1 mol of RNA. Using both pancreatic RNase and RNase T(1) to digest viral RNA labeled by (3)H-uridine, (3)H-cytidine, or (3)H-guanosine, the weight of the virion RNA of vesicular stomatitis virus (VSV) is estimated as 3.82 +/- 0.14 x 10(6) whereas that of the VSV-defective T particle is estimated as 1.23 +/- 0.04 x 10(6).
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PMID:Determination of the molecular weight of animal RNA viral genomes by nuclease digestions. I. Vesicular stomatitis virus and its defective T particle. 435 68

Cells of a continuous cell line derived from rabbit embryo fibroblasts were infected with herpes simplex type 1 virus (HSV-1) and maintained in the presence of either [5-(3)H]uridine or [methyl-(3)H]thymidine or (32)PO(4) (3-). Nucleocapsids were isolated from the cytoplasmic fraction, partially purified, and treated with DNase and RNase. From the pelleted nucleocapsids, DNA was extracted and purified by centrifugation in sucrose and cesium sulfate gradients. The acid-precipitable radioactivity of [5-(3)H]uridine-labeled DNA was partially susceptible to pancreatic RNase and alkaline treatment; the susceptibility to the enzyme decreased with increasing salt concentration. No drop of activity of DNA labeled with [(3)H]thymidine was observed either after RNase or alkali treatment. Base composition analysis of [5-(3)H]uridine-labeled DNA showed that the radioactivity was recovered as uracil and cytosine. In the cesium sulfate gradient, the purified [5-(3)H]uridine-labeled DNA banded at the same position as the (32)P-labeled DNA. The present data tend to suggest that ribonucleotide sequences are present in HSV DNA, that they are covalently attached to the viral DNA, and that they can form double-stranded structures.
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PMID:Ribonucleotides linked to DNA of herpes simplex virus type 1. 436 94

The buoyant density of acute haemorrhagic conjunctivitis virions labeled with either [(3)H]uridine or [(3)H]leucine was 1.34 g/ml in CsCl and 1.25 g/ml in sucrose. RNA extracted from the virions gave a sedimentation coefficient of approximately 34S in sucrose, and was found to be sensitive to RNase. Molecular weight of RNA was calculated to be 2.5 x 10(6) using poliovirus RNA for reference.
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PMID:Purification and biophysical properties of acute haemorrhagic conjunctivitis virus. 443 Oct 83

Advantage was taken of the reversibility of the first step of ribonuclease-A action to synthesize the dinucleoside phosphorothioate Up(S)C from the crystalline isomer of uridine 2',3'-cyclic phosphorothioate [Up(S)] and cytidine. Cyclic phosphorothioate was then reformed from Up(S)C by a nonenzymic reaction known to proceed by an in-line mechanism. The geometry of the enzymic reaction was determined to be in-line by a comparison of the Up(S) product with the Up(S) originally used. By the principle of microscopic reversibility, the geometry of the first step in the action of ribonuclease-A is shown to be in-line.
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PMID:Geometry of the first step in the action of ribonuclease-A (in-line geometry-uridine2',3'-cyclic thiophosphate- 31 P NMR). 450 May 43

Polyadenylylated RNA from sea urchin embryos concomitantly labeled with [(3)H]adenosine and [(14)C]uridine between fertilization and the four-cell stage was used to determine whether the RNA primers prerequisite to the massive polyadenylylation known to occur after fertilization are synthesized during oogenesis or subsequent to fertilization. Characterization of this RNA and unlabeled RNA via retention on nitrocellulose membranes and poly(U)-impregnated filters, molecular hybridization with [(3)H]poly(U), RNase resistance, oligo(dT)-cellulose chromatography, and size-distribution studies indicates that the poly(A) tracts synthesized after fertilization are predominantly appended to preexisting cytoplasmic primers of oogenic origin. Hence, if polyadenylylation is involved in the selective editing of presumptive genetic messages, this process is not confined to the nucleus unless a given codogenic transcript can undergo more than one cycle of adenylylation.
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PMID:Polyadenylylation and transcription following fertilization. 452 19

After the incubation of reovirus replicase reaction mixtures (containing labeled ribonucleoside triphosphates), partially double-stranded ribonucleic acid (pdsRNA) products were isolated by cellulose column chromatography followed by precipitation with 2 m NaCl. The pulse-labeled reaction product contained a significantly large amount of pdsRNA that became complete dsRNA as reaction time increased, indicating that pdsRNA was an intermediate of the replicase reaction. The newly synthesized RNA strand ((3)H-labeled) of the pdsRNA was resistant to ribonuclease digestion, suggesting that single-stranded RNA regions were part of a preexistent unlabeled RNA template. These observations, together with the electrophoretic behavior of the pdsRNA in polyacrylamide gel, are consistent with the hypothesis that dsRNA is synthesized by the elongation of a complementary RNA strand upon a preexistent template of single-stranded RNA (i.e., messenger RNA). The direction of the RNA strand elongation was determined by carrying out the replicase reaction in the presence of (3)H-cytidine triphosphate (or (3)H-uridine triphosphate) and adenine triphosphate-alpha-(32)P followed by a chase with excess unlabeled cytidine triphosphate (or uridine triphosphate). The dsRNA product was digested with T1 ribonuclease and the resulting 3'-terminal fragments were isolated by chromatography on a dihydroxyboryl derivative of cellulose. Examination of the ratio of (3)H to (32)P in these fragments indicated that RNA synthesis proceeded from the 5' to 3' terminus.
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PMID:Reovirus replicase-directed synthesis of double-stranded ribonucleic acid. 467 85


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