Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.5 (RNase)
 17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Modified Giemsa procedures have been developed which elicit differential and highly selective staining of individual Y chromosomal lampbruch loops in spermatocyte nuclei of Drosophila hydei, D. NEOHYDEI, AND D. eohydei. In all three species the Y loop pair known as the "clubs" stains a brilliant dark red with Giemsa at pH 10. With the same treatment other loop pairs either remain unstained, e.g. the "threads", or show a differentiation between light blue and pink staining material, e.g. "pseudonucleolus" and "cones" in D. hydei and D. eohydei. With eosin at pH 2.8 the "threads" in D. hydei can be stained intensely, as well as one matrical component of th "pseudonucleolus". Pretreatment with RNase or TCA removes all stainability from the Y loops with Giemsa at Ph 10. TCA treatment enhances eosin staining at pH 2.8. These and other variations of Giemsa may be utilized to establish homologies between Y loops in different species. The molecular basis of the staining reactions remains to be elucidated.
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PMID:Selective staining of Y chromosomal loops in Drosophila hydei, D. neohydei, and D. eohydei. 6 13

Electron micrographs reveal that the Ag-stainable substance is located on the outside of NOR's or around them but not in the chromosomes themselves. In association figures, the Ag-positive material lies between the acrocentric chromosomes. Light-microscopic studies show that the Ag stainability of the nucleolus in interphase is correlated with the function of the NOR, as seen from inactive and activated lymphocytes. Much more Ag-positive material is seen in prophase than in meta- and anaphase. It starts to increase again in late telophase. In male meiosis the NOR's remain Ag-positive until pachytene. First and second metaphase figures are negative. Experiments using RNase, TCA, and trypsin indicate that the Ag-stainable substance is an acidic protein. The precipitation of Ag granules in interphase nuclei seen in the electron microscope is greatest over the fibrillar component of the nucleolus. The most likely interpretation is that the Ag-stainable material is a component of ribonucleic protein accumulating around active NOR's. In mitosis some of this material remains at the NOR's. In first meiosis it is completely removed before diakinesis.
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PMID:The nature of the Ag-staining of nucleolus organizer regions. Electron- and light-microscopic studies on human cells in interphase, mitosis, and meiosis. 7 8

Purified 15 S globin mRNA-protein (mRNP) complexes obtained by EDTA dissociation of duck reticulocytes polyribosomes were digested with the calcium dependant Staphylococcus aureus nuclease (EC 3. 1. 4. 7.). 25% of the globin mRNA sequences were resistant to extensive nuclease digestion as determined by TCA precipitation of the digested 15 S particles labelled in vivo with tritiated uridine. Polyacrylamide gel electrophoresis of the RNA from nuclease digested 15 S particles showed that the protected oligoribonucleotides were distributed into two distinct size classes of 25,000 and 12,000 MW. Comparison between in vitro iodine-labelled 9 S globin mRNA extracted from Staphylococcal nuclease digested 15 S mRNP particles was carried out by fingerprinting. Mapping of T1 ribonuclease digests by high-voltage electrophoresis and homochromatography showed that specific oligoribonucleotides were protected against nuclease attack by proteins of the 15 S mRNP.
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PMID:Evidence for the protection of specific RNA sequences in globin messenger ribonucleoprotein particles. 11 Dec 30

The incorporation of exogenous thymidine and thymine into acid-insoluble material of Thermoactinomyces vulgaris has been studied during germination and subsequent growth. Thymine is not incorporated. The incorporation of thymidine stops after a short time due to the rapid breakdown of thymidine to thymine and deoxyribose-1-phosphate by the inducible thymidine phosphorylase. Deoxyadenosine enhances the incorporation of thymidine as well as of thymine and prolongs the tine of uptake. Uridine stimulates only the incorporation of thymidine but not of thymine. These effects can be explained by the function of these substances within the salvage pathway. Deoxyadenosine acts as donor of deoxyribosyl groups being necessary for the conversion of thymine to thymidine by thymidine phosphorylase and uridine inhibits thymidine phosphorylase, and thereby it prevents the degradation of thymidine to thymine. Thymidine is incorporated into alkali-, RNase-and protease-stable, hot TCA-soluble and DNase-sensitive material. That means that the cellular DNA of T. vulgaris can be specifically labelled by radioactive thymidine in the presence of deoxyadenosine and uridine, respectively.
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PMID:[Incorporation of thymidine into the DNA of actinomycetes. I. Incorporation of exogenous thymidine into the DNA of Thermoactinomyces vulgaris]. 30 39

Previous studies showed that an antigen found in the circulation of animals heavily infected with Schistosoma mansoni was extracted in a trichloroacetic acid soluble-chloroform insoluble fraction (TCA-S-C) of adult worms. Antigenic activity was destroyed by periodate treatment but remained unaltered after treatment with proteolytic enzymes, DNase, RNase, and lyophilization. In the present study, chromatography of TCA-S-C on a DEAE cellulose column revealed six substances, one of which was antigenic. After electrophoresis in agarose antigenic activity corresponded to a slower moving, toluidine blue-staining material. A faster moving, toluidine blue-staining substance seems to be responsible for the large 260 nm, absorbing peak. Analysis of a fraction containing only antigen revealed a large amount of carbohydrate, primarily N-acetylglucosamine and D-glucuronic acid but also galactase, glucose, N-acetylglucosamine, and trace amounts of other sugars. Amino acids accounted for about 11% of the weight of the antigen. The antigen appears to be a proteoglycan.
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PMID:Further purification and characterization of a circulating antigen in schistosomiasis. 41 Aug 79

Isolated rat liver nuclei were incubated under conditions when RNA polymerase I or RNA polymerase II was preferentially active. It was shown that [gamma-32P] ATP and [gamma-32P] GTP were incorporated into phenol extractable, TCA-precipitable material. RNase, actinomycin D, heparin and, in the case of RNA-polymerase II, alpha-amanitine inhibited precursor incorporation. These data are interpreted as evidence in favour of the initiation of RNA synthesis in isolated rat liver nuclei.
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PMID:[Initiation of RNA synthesis in isolated rat liver nuclei]. 258 May 66

When E. coli carrying multicopy plasmids for fructose-1,6-P2 aldolase or phosphoglycerate kinase was grown in the presence of 32Pi, there was label at the position of cognate high level polypeptide after SDS-PAGE. As tested for aldolase, the label was resistant to acetone, RNase, and hot TCA treatments, and was also observed by immunoprecipitation, which was competed for by purified aldolase. Incorporation of label also occurred in the presence of chloramphenicol. Immunoprecipitation revealed apparent aldolase labeling in the wild type strain as well.
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PMID:Phosphate modification of fructose-1,6-bisphosphate aldolase in Escherichia coli. 328 66

Tritiated 8-methoxypsoralen was given perorally to rats in amounts corresponding to therapeutic human doses. The rats were exposed to UVA light or kept in darkness. None of the fractions (apart from 3H2O from the lens) examined changed their level of radioactivity under the influence of UVA light. Time-radioactivity curves were recorded for the skin, lens, residual eye, and the liver. Four fractions were measured: 3H2O, soluble pool, DNA-RNA, and protein. Tritiated water appeared already 1 h after ingestion, and attained maximum value 9-24 h after ingestion, indicating the efficiency with which the liver degrades 8-MOP. 3H-8-MOP and metabolites could be detected in the soluble pool in maximum amounts 2-3 h after the administration. Pretreatment with trypsin increased the concentration of 3H-8-MOP and metabolites; the origin of this extra radioactivity was the protein fraction. The 3H-8-MOP binding to DNA or RNA was studied by pretreatments of the homogenates with DNase or RNase followed by measurement of radioactivity in the TCA extracts. This indicated that no measurable amount of 3H-8-MOP had been bound to DNA or RNA. We conclude that 8-MOP administered to rats in amounts corresponding to human therapeutic doses does not bind to DNA or RNA in measurable amounts either after UV-light or in darkness. The experiments have shown proteins to be the main binding site in rat organs.
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PMID:Localization of radioactivity in rat organs after oral administration of tritiated 8-methoxypsoralen in therapeutic doses. 619 23

Four, widely used, ribonucleases were found to protect their substrates from acid precipitation by causing, evidently, a modification of their physicochemical properties. The protection was dependent on the kind of substrate while the ratio of protective to nucleolytic activity varied widely between the four enzymes. The protection was enhanced by some nucleotides like UMP, CMP and IMP and decreased in the presence of several bivalent ions like Zn++, Co++ and Cu++. It was completely abolished when the substrates were hybridized with their complementary ribohomopolymers. In the case of bovine pancreatic ribonuclease, the part of the molecule which was responsible for the protective activity was localized on the enzyme domain characterized as S-protein, which lacks nucleolytic activity. The observed property of ribonucleases could lead to false data when the measurement of TCA-soluble material is the method used to follow the purification of ribonucleases or to study their activity. It was also found that ribonuclease S-protein enhances the catalytic activity of B. Cereus RNAse. S-protein could potentiate other RNAses activity like onconase, which has recently been used as an anticancer agent.
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PMID:Ribonucleases protect RNA from acid precipitation. 948 43

Restraint stress (RS) applied to mice during acute infection with Theiler's virus causes corticosterone-induced immunosuppression. This effect was further investigated by measuring chemokine changes in the spleen and central nervous system (CNS) using an RNase Protection Assay. mRNAs for lymphotactin (Ltn), interferon-induced protein-10 (IP-10), MIP-1 beta, monocyte chemoattractant protein-1 (MCP-1) and TCA-3 were detected in the spleen at day 2 pi, but not in the brain of CBA mice infected with Theiler's virus. Ltn, IP-10 and RANTES were elevated in both the spleen and the brain at day 7 pi, and were significantly decreased by RS in the brain. RS also resulted in decreased inflammation within the CNS.
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PMID:Alterations in chemokine expression following Theiler's virus infection and restraint stress. 1514 9


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