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)

The poly(adenylic acid) [poly (A)] segment in mouse sarcoma polysomes in not hydrolyzed by snake venom exonuclease under conditions which cause extensive degradation of the poly(A) in deproteinized polysomal RNA. The protecting effect of polysomes is presumably caused by the interaction between the poly(A) sequence and the protein known to be associated with it. This protection is reduced at low KCl concentration, but addition of exogenous RNA restores the protecting effect. The poly(A) segment also becomes susceptible to exonuclease after fragmentation of the polysomes by mild ribonuclease treatment. The latter treatment releases the poly(A) in association with protein. The poly(A) sequence in polysomes in readily degraded by a cytoplasmic extract of S-180 cells. Partial purification leads to a preparation active against the poly(A) in polysomes under conditions where no fragmentation of the messenger RNA is observed. Snake venom exonuclease increases the activity of the cytoplasmic preparation against poly(A) in polysomes. The active cytoplasmic factor appears to interfere with the poly(A)-protein interaction, thus rendering the polynucleotide susceptible to degradation by exonuclease. The poly(A) sequences in polysomes and in free cytoplasmic nucleoprotein particles are hydrolyzed to the same extent. The results suggest that the poly(A) sequence is normally protected from nucleases by virtue of its association with protein. The slow reduction in poly(A) size in cytoplasmic mRNA can be accounted for by a factor capable of interfering with the poly(A)-protein interaction. The latter interaction seems also dependent on the structural integrity of the polysomes or messenger ribonucleoproteins. It is suggested that a polynucleotide segment adjacent to the poly(A) can modulate the affinity of the protein for the latter sequence, thus permitting control of poly(A) stability in individual messenger RNAs.
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PMID:Control of breakdown of the polyadenylate sequence in mammalian polyribosomes: role of poly(adenylic acid)-protein interactions. 55 45

The antitumor effect of reserve polysaccharide, paramylon, from Euglena gracilis on the transplantable sarcoma-180 was examined in mice. This polysaccharide had an effect similar to that of lentinan. Paramylon, in a dose of 1 mug/g body weight, injected intraperitoneally 24 hr after tumor implantation had an inhibitory effect on the tumor growth, although without causing complete regression of the tumor. Alkaline-treated paramylon had a similar effect but at a smaller concentration than the native one. The inhibitory activity was not lost when the paramylon preparation was treated with pronase, DNase, or RNase. The antitumor effect might be a lymphocyte-mediated process. In tumors that were regressing after treatment, there was extensive outpouring of lymphoid cells with plasma cells and macrophages. A test conducted using paramylon ruled out the possibility of an interferon-mediated inhibiotry effect on tumor growth.
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PMID:Antitumor activity of paramylon on sarcoma-180 in mice. 82 42

The cross-linked dimer of bovine pancreatic RNase (M.W. 28,000) is significantly more effective than the monomer in inhibiting tumor development in mice when administered i.p. 1 day after inoculation with sarcoma 180J ascites cells. Animals bearing solid tumors were not affected. In AKR/J mice with advanced leukemia, a single i.p. injection of 100 mug of the dimer led to about 50% reduction in the enlarged lymph nodes and the spleen at 24 hr. The half-life of the dimer in the bloodstream has been determined to be 10 min in rats and 6 min in mice, compared to values of 5 and 3.5 min, respectively, for the monomer. Analyses of the tissues of untreated leukemic mice for RNase and RNase inhibitors show that the tumor tissues are not deficient in RNase activity. Considerations of possible mechanisms of action of the dimer indicate that other basic proteins in this size range may merit examination as cytostatic agents toward transformed cells.
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PMID:Comparison of antitumor activities of pancreatic ribonuclease and its cross-linked dimer. 97 50

The bone inducing factor derived from BF osteosarcoma was purified in the following manner. Step 1. The sarcoma, grown in CBA mice, was excised and lyophilized. Step 2. The powder was washed with chilled acetone. Step 3. The acetone-treated powder was then homogenized with chilled distilled water. Step 4. Washing with 0.15M KCl. Step 5. The precipitate was incubated in in 0.2 N NH2OH, pH7.0, for 48 H at 25 degrees. After Step 5, the bone-forming activity showed a slight increase; however, the factor remained insoluble. The properties of the factor were as follows. The factor is relatively relatively heat stable; the osteogenic activity survived the treatment at 75 degrees for 15 min or at 55 degrees for 19 h. The activity was easily lost by mechanical shaking. Incubation with DNase, RNase, neuraminidase, chondroitinase ABC and beta-galactosidase left the osteogenic activity intact, but treatment with either pronase or collagnease destroyed this activity. The results suggest that the factor may be a protein. The activity was seen with the lyophilized BF osteosarcoma cells (without matrix), and it is probable that the factor was exclusively synthesized in the cells. The bone formation, observed across a millipore filter when living BF osteosarcoma enclosed in a millipore chamber was implanted in mice, suggests the synthesis and secretion of the factor from the cells.
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PMID:Studies on a factor responsible for new bone formation from osteosarcoma in mice. 105 58

It has been shown earlier that after in vivo administration, dibromodulcitol (DBD) reacts with DNA and to a greater extent with chromosomal proteins of Yoshida sarcoma cells. The present experiments were designed to show if the binding of DBD to the chromatin elements of Yoshida sarcoma cells causes any changes in RNA synthesis using either DNA or chromatin as template in bacterial RNA polymerase system. During 4 to 24 h following in vivo administration, DBD reduces the template activity of dna without detectable single-strand breaks in the template DNA in alkaline sucrose gradients. Using chromatin as template the same dose of DBD produces no or very slight inhibition of RNA synthesis. Measuring the DNA-dependent RNA synthesis in nuclei isolated from Yoshida cells of treated rats, the dose of DBD which markedly inhibited the template activity of DNA, resulted in a significant stimulation of the nuclear RNA synthesis. The increased RNA synthesis was not due to an inhibition of ribonuclease activity. The observed alterations of the transcriptive properties of chromatin and nuclei produced by DBD are interpreted as being due to a modification of the whole nucleoprotein structure caused by the interaction of DBD with both DNA and chromosomal proteins.
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PMID:The effect of dibromodulcitol on the template activity of DNA chromatin and nuclei from Yoshida sarcoma cells. 125 31

The major excreted protein of transformed mouse fibroblasts (MEP) has recently been identified as the lysosomal cysteine protease, cathepsin L. The synthesis and intracellular trafficking of this protein in mouse fibroblasts are regulated by growth factors and malignant transformation. To further define the basis for this regulation, a cDNA encoding MEP/cathepsin L was isolated from a mouse liver cDNA library and used to compare cathepsin L of normal and Kirsten sarcoma virus-transformed NIH 3T3 fibroblasts. Although cathepsin L message levels were elevated 20-fold in the transformed fibroblasts, normal and transformed cells displayed similar cathepsin L genomic DNA digest patterns and gene copy numbers, and cathepsin L mRNA sequences appeared identical by RNase protection analysis. These findings indicate that (i) cathepsin L is synthesized from the same gene in normal and transformed cells and (ii) cathepsin L polypeptides made by these cells are translated with the same primary sequence. Cathepsin L polypeptides synthesized by quiescent, growing, and transformed cells displayed similar isoelectric focusing patterns, suggesting similar post-translational modification. Site-directed mutagenesis of the mouse liver cDNA and expression in COS monkey cells was used to examine the glycosylation of mouse cathepsin L. The results indicated that only one of the two potential N-linked glycosylation sites (the one at Asn221) is glycosylated. Analysis by ion exchange chromatography on QAE-Sephadex, and affinity chromatography on mannose 6-phosphate receptor-Affi-Gel 10, indicated that the cathepsin L oligosaccharide was phosphorylated similarly in normal and transformed cells. Although several phosphorylated oligosaccharide species were observed, the major species contained two phosphomonoester moieties and bound efficiently to the receptor. These findings suggest that cathepsin L made by normal and transformed mouse fibroblasts are identical and substantiate the hypothesis that trafficking of cathepsin L in these cells is regulated by growth-induced changes in the lysosomal protein transport system.
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PMID:Comparison of cathepsin L synthesized by normal and transformed cells at the gene, message, protein, and oligosaccharide levels. 227 56

The ribonuclease inhibitor from human placenta is a tight-binding inhibitor of alkaline and neutral ribonucleases, including the blood vessel-inducing protein, angiogenin. The location of the inhibitor gene within the human genome has now been determined. Utilizing human-rodent hybrid cell lines, it was found on chromosome 11. The localization was refined to chromosome band 11p15 by in situ hybridization of the ribonuclease inhibitor cDNA to normal metaphase chromosomes. A further refinement was obtained by in situ hybridization of the probe to metaphase chromosomes from RPMI 8402 cells, a line containing a well-characterized translocation t(11;14)(p15;q11) with a chromosome 11 breakpoint between the insulin-like growth factor 2 (IGF2) and Harvey rat sarcoma viral oncogene homolog genes. This analysis has localized the ribonuclease inhibitor gene to chromosome subband 11p15.5, distal to the IGF2 gene.
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PMID:The placental ribonuclease inhibitor (RNH) gene is located on chromosome subband 11p15.5. 227 43

The human B-cell line RJ2.2.5, derived by mutagenesis from a Burkitt lymphoma cell line and selected for loss of HLA class II antigen expression, was infected with recombinant retroviruses containing either the Harvey murine sarcoma virus oncogene v-Ha-ras or the human neuroblastoma homolog NRAS. Both activated ras genes partially complemented the regulatory defect in RJ2.2.5 and specifically increased the expression of the DR and DQ subsets of HLA class II genes. Blot-hybridization analysis and RNase mapping indicated that HLA-DQ alpha-chain mRNA in the infected cell lines was increased to a level at least 50% that of the parent B-cell line, Raji. The levels of HLA-DR and -DQ beta-chain RNA also were increased but to a lesser extent. In contrast, we detected no effect of ras on the quantities of other class II, class I, or invariant-chain mRNAs. Fluorescence-activated cell sorter analysis with antibodies recognizing HLA-DR, -DQ, and class I antigens supported these observations. Enhancement of HLA class II gene expression by ras genes may have important implications for regulation of the immune system in response to transformation.
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PMID:Defective HLA class II expression in a regulatory mutant is partially complemented by activated ras oncogenes. 331 16

Virus particles were continuously produced by a cell line (78A1) of rat embryo fibroblasts that had been transformed by the murine sarcoma-leukemia virus complex. Since most of the mature virions were found in the extracellular fluid and were not cell-associated, a measurable quantity of viral ribonucleic acid (RNA) could not be extracted from these cells. Cycloheximide, a protein inhibitor, was successfully used to accumulate viral RNA within the cells. This ribonuclease-sensitive RNA, with a sedimentation coefficient of 71S, had the same base composition as the high molecular weight RNA (S(20,w) = 71) isolated from purified virions released by the transformed cells.
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PMID:Characterization of intracellular ribonucleic acid specific for the murine sarcoma-leukemia virus complex. 430 49

A highly active and stable DNA polymerase was found in purified preparations of two murine sarcoma viruses. Enzyme activity is not detected in most virus preparations unless they are treated with low concentrations of a nonionic detergent such as Nonidet P-40. The incorporation of labeled thymidine triphosphate requires all four deoxyribonucleoside triphosphates and either Mg(2+) or Mn(2+). Enzyme activity is proportional to virus concentration and is linear with time up to 90 min. That the template is RNA is suggested by the reduction in polymerase activity upon treatment of murine sarcoma virus with RNase, and by the absence of detectable amounts of DNA in the virus. That the product is DNA is shown by the incorporation of all four deoxyribo-nucleoside triphosphates into an acid-insoluble product which is stable in alkali, is destroyed by DNase, sediments in alkaline sucrose gradients with a sedimentation coefficient of 7 S, and bands in isopycnic CsCl gradients with a mean buoyant density of 1.700.
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PMID:Mechanism of carcinogenesis by RNA tumor viruses. I. An RNA-dependent DNA polymerase in murine sarcoma viruses. 431 86


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