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)

(1) The regulation of the accumulation of the isoflavonoid-derived phytoalexin phaseollin in cell suspension cultures of Dwarf French Bean (Phaseolus vulgaris/ has been investigated. (2) An elicitor preparation from cell walls of Colletotrichum lindemuthianum, the causal agent of anthracnose disease of French bean, caused a marked accumulation of phaseollin in the cultures. The elicitor induced phaseollin accumulation to a level of 60% that obtained with the artificial elicitor autoclaved ribonuclease A and was maximally active at a concentration (weight basis) of at least 50 times lower than required for maximal response to ribonuclease. (3) Elicitor preparations from cell walls of Phytophthora megasperma var. sojae, a fungal pathogen of soybean, and Botrytis cinerea, the common grey mould, were much less effective than the C. lindemuthianum wall-released elicitor. (4) There was a marked but transient increase in the extractable activity of phenylalanine ammonia-lyase, the enzyme catalysing the first reaction in the biosynthesis of phaseollin from L-phenylalanine, in response to the elicitor from C. lindemuthianum. (5) Comparative density labelling with 2H from 2H2O indicated that the elicitor stimulates de novo synthesis of phenylalanine ammonie findings provide the basis of a scheme for elicitor induction of phytoalexin accumulation.
Biochim Biophys Acta 1979 Sep 03
PMID:Stimulation of de novo synthesis of L-phenylalanine ammonia-lyase in relation to phytoalexin accumulation in Colletotrichum lindemuthianum elicitor-treated cell suspension cultures of french bean (Phaseolus vulgaris). 47 49

The double-stranded form of cucumber mosaic virus-associated RNA 5 has been purified and further characterized. Its molecular weight determined by sedimentation equilibrium is 2.15 . 10(5). The buoyant density calculated from its symmetrical distribution in Cs2SO4, following isopycnic ultracentrifugation, is 1.615 g/cm3. The sedimentation rate of double-stranded cucumber mosaic virus-associated RNA 5 is slightly greater than that of cucumber mosaic virus-associated RNA 5; its electrophoretic mobility in polyacrylamide gel (2.4%) is less than that of cucumber mosaic virus-associated RNA 5. By the above standards the double-stranded cucumber mosaic virus-associated RNA 5 preparations used were found to be nomogeneous in size as well as density. Thermal denaturation monitored by means of ultraviolet light absorption produced multitransitional denaturation profiles. The average melting temperature (Tm) was 88 degrees C in 0.1 x SSC. Monotransitional denaturation profiles and slightly higher Tm values were obtained when resistance against ribonuclease digestion was measured. These denaturation experiments and other propertied led to the conclusion that double-stranded cucumber mosaic virus-associated RNA 5 and the double-stranded form of peanut stunt virus-associated RNA 5 are small double-stranded nucleic acids with several homostable base-pair regions, characterized by distinct G + C contents and Tm values.
Biochim Biophys Acta 1979 Sep 27
PMID:Cucumber mosaic virus-associated RNA 5. VI. Characterization and denaturation-renaturation behavior of the double-stranded form. 48 81

During the first 10 days after peripheral deafferentation of the mouse olfactory bulb stereoselective binding of L-[3H]carnosine declines markedly. The initial phase of this decline is due to a decrease in binding site stereoselectivity, which is then followed by a loss of assayable binding sites. The specificity of inhibition of L-[3H]carnosine binding by various peptides is also altered after denervation. Competitive inhibitors of carnosine binding become less potent after denervation, while analogues which are not competitive inhibitors remain equipotent before and after denervation. Several carnosine analogues that are normally poor inhibitors become more potent after denervation. Treatment of bulb membranes with trypsin, RNase and hyaluronidase, but not DNase or collagenase, resulted in significant alterations in carnosine binding. L-, but not D-carnosine, protected the binding site from trypsin digestion, and induced additional binding in bulb membranes in a dose-and temperature-dependent fashion. Preincubation of membranes with L-carnosine also led to the induction of additional carnosine binding in membranes from cerebral cortex, cerebellum and deafferentated bulbs but not from muscle. Bulbs from newborn mice contain about one-half of the adult levels of binding and no significant sex differences in carnosine binding were detected in bulbs from adult rats. L-[3H]carnosine binding was two-fold higher in the anterior compared to the posterior portion of the bulb, but there were no significant differences in binding of opiate, GABA, alpha-adrenergic, muscarinic cholinergic, benzodiazepine of glutamic acid receptor ligands.
Brain Res 1979 Sep 28
PMID:L-[3H]Carnosine binding in the olfactory bulb. II. Biochemical and biological studies. 48 25

A variety of 5'-3H-methyl-labeled, oxidized viral mRNAs were used as probes for detecting in wheat germ initiation complexes proteins that interact with, and can be cross-linked to, the 5'-cap structure. A limited and reproducible set of specific proteins was obtained with the different mRNAs. The binding of these proteins to the 5'-end of mRNA apparently results in protection against nucleotide pyrophosphatase digestion of the cap even in initiation complexes in which the 5'-end is susceptible to pancreatic RNase digestion. Cross-linked proteins from mammalian initiation complexes comigrated with several of the subunits of similarly treated eIF-3. A model for cap binding protein interaction with mRNA cap during initiation of translation is suggested.
Nucleic Acids Res 1979 Sep 11
PMID:Interaction of a limited set of proteins with different mRNAs and protection of 5'-caps against pyrophosphatase digestion in initiation complexes. 49 38

The previous reports of inhibition of alcohol dehydrogenase and lactate dehydrogenase by the vitamin folic acid and its analogues are in error. The high absorbance of solutions containing folate causes distortion of the measurements of reaction velocities, leading to apparent inhibitions. When cuvettes of sufficiently short optical path length are used, no inhibition by folate can be observed. Similarly, the reported inhibition of ribonuclease by folate is an artifact. Glutamate dehydrogenase and dihydropterin reductase actually are inhibited by folate. The reported nonspecific inhibitions of over a dozen enzymes by folate, though, must be regarded as erroneous.
Can J Biochem 1979 Sep
PMID:Nonspecific inhibition of dehydrogenases by folates: an artifact. 50 60

(1) When rat liver 40 S ribosomal proteins in 6 M urea were were mixed with poly(U) at an appropriate ratio, a precipitate was formed which was also insoluble in the sample solution for two-dimensional acrylamide gel electrophoresis. Analyses by two-dimensional acrylamide gel electrophoresis showed that S7 and S10 proteins (according to our numbering system) had disappeared selectively from the fraction soluble in 6 M urea. These two proteins were present in the fraction insoluble in 6 M urea, and became soluble in the sample solution after treating it with RNase. The results suggest that S7 and S10 proteins have strong affinities for poly(U). When rat liver 40 S subunits were incubated with poly(U), similar results were obtained. (2) After incubation of 40 S subunits with [3H]poly(U) and then with unlabeled poly(U), UV irradiation cross-linked poly(U) to the protein moiety of the 40 S subunit. When the protein fraction insoluble in the sample solution for two-dimensional electrophoresis was prepared from 40 S subunits cross-linked to poly(U) and then subjected to two-dimensional acrylamide gel electrophoresis after RNase treatment, S7 and S10 proteins were detected on the gel. In addition to the S7 protein spot, a triangular area spreading from the spot to the origin contained radioactivity. The results suggest that poly(U) is cross-linked to S7 protein and oligo(U) fragments bound to S7 protein affect its electrophoretic mobility. (3) Ribosomal proteins were prepared from 40 S subunits cross-linked to carrier-free [3H]poly(U) and analyzed by three-dimensional acrylamide gel electrophoresis (Terao, K. & Ogata, K. (1975) Biochim. Biophys. Acta 402, 214--229) after RNase treatment. It was found that S7, S6, and S15 proteins are cross-linked to poly(U). From the results of the present and preceding experiments it is concluded that S7 is the poly(U)-binding protein. The possibility that other proteins in 40 S ribosomal subunits interact with poly(U) is discussed.
J Biochem 1979 Sep
PMID:Proteins of small subunits of rat liver ribosomes that interact with poly(U). II. Cross-links between poly(U) and ribosomal proteins in 40 S subunits induced by UV irradiation. 51 42

Classically, one can increase the titer of an agglutinating or first antibody with an antiglobulin or second antibody. We have used an avidin-biotin system in place of antiglobulin to similarly extend the agglutination by an initial anticellular antibody. Erythrocytes were agglutinated by adding in succession, caproylamidobiotin-antibody, avidin, and extender (caproylamidobiotin-macromolecule). The macromolecules evaluated as extenders, in order of increasing potency, were fibrinogen, albumin, succinylated polylysine, and ribonuclease A. From comparative testing, we found that antiglobulin raised the titer of antibody from 2560 to 20,480, and the avidin-biotin tool raised the titer of caproylamidobiotin-antibody from 2560 to 10,240 without extender and to 81,820 with an extender of caproylamidobiotin-ribonuclease. Thus noncovalent extenders add to the capability of the avidin-biotin system to facilitate and substitute for an antibody.
Clin Chem 1979 Sep
PMID:Enhancement of immune cellular agglutination by use of an avidin-biotin system. 57 47

1. Vitamin A deficiency led to an increase in the oligonucleotide fraction of testes and intestinal mucosa of rats at the expense of high-molecular-weight RNA and 4S RNA, but no such changes were observed in the liver. Retinyl acetate supplementation reversed these effects in both tissues, whereas retinoic acid supplementation was almost equally effective in the mucosa but virtually ineffective in the testes. The ribonuclease activities of all the tissues remained unaffected by the above treatments. 2. The effect of vitamin A deprivation on the acceptor activity of the tRNA of the testes and intestinal mucosa was more pronounced than on the liver tRNA. The testes and mucosal tRNA of the retinoic acid-supplemented rats showed significantly lower charging capacity as compared with the retinyl acetate-supplemented ones. Here also no significant effect was observed on the liver tRNA. 3. Vitamin A deficiency caused a decrease in the percentage of poly(A) in RNA of the mucosa and testes, but not in the liver RNA. The poly(A) contents of both tissues were brought to normal by retinyl acetate supplementation; treatment with retinoic acid led to an appreciable increase in poly(A) in the mucosa, but considerably less increase in poly(A) in the testes. 4. The incorporation of H332PO4 into the rRNA and tRNA of the testes was lowered by vitamin A deficiency, but no such effects was observed in the liver RNA.
Biochem J 1977 Sep 15
PMID:Effect of vitamin A nutritional status on the ribonucleic acids of liver, intestinal mucosa and testes of rats. 59 29

The antibiotic edenine induces binding of multiple 40 S ribosomes to reovirus messenger RNAs, producing complexes that sediment rapidly in glycerol gradients. Rapidly sedimenting complexes were also obtained with tobacco mosaic virus RNA and rabbit globin mRNA in the presence of edeine. Following ribonuclease digestion of the heavy complexes, nuclease-resistant 32P-labeled reovirus fragments protected by 40 S ribosomes in the presence of edeine were recovered and fingerprinted. The sequence complexity of the protected material supports the interpretation that 40 S subunits are distributed at many internal sites in each messenger RNA. Additional experiments indicate that binding of the multiple 40 S subunits occurs from a single "entry site" which involves the 5' terminus of the message. This, in turn, implies that in the presence of edeine 40 S ribosomes are able to move along the mRNA chain, attaching initially near the 5' end, then advancing to make room for the next subunit. We suggest that in the absence of antibiotics, also, a 40 S ribosome might bind near the 5' terminus and then advance, stopping where it encounters the first AUG triplet. The effect of edeine might be to interfere with the AUG recognition process, thus allowing the 40 S ribosome to continue unhalted along the message. The present experiments with edeine provide the first direct evidence that 40 S ribosomal subunits are capable of moving along the mRNA chain.
J Biol Chem 1978 Sep 25
PMID:Migration of 40 S ribosomal subunits on messenger RNA in the presence of edeine. 68 67

The heterogeneous nuclear RNA-protein (hnRNP) fibers in HeLa cell nuclei are visualized by a nuclear subfractionation technique which removes 96% of the chromatin in a single step and 99% in a two-step elution but leaves the bulk of the hnRNA complexed with the remnant nuclear structure or lamina. Both steady-state and newly synthesized (approximately 15-s label) hnRNA are associated with the remnant nuclei to about the same extent. This association does not appear to depend on the presence of chromatin and exists in addition to any possible association of hnRNP with chromatin itself. Electron microscopy of partially purified nuclear hnRNA complexes shows that the hnRNP fibers form a ribonucleoprotein network throughout the nucleus, whose integrity is dependent on the RNA. Autoradiography confirms that hnRNA is a constituent of the fibers. The RNA network visualized in these remnant nuclei may be similar to RNA networks seen in intact cells. The hnRNA molecules appear to be associated with the nuclear lamina, at least in part, by unusual hnRNA sequences. More than half of the recovered poly(A) and double-stranded hnRNA regions remains associated with the nuclear structures or the laminae after digestion with RNase and elution with 0.4 M ammonium sulfate. In contrast, the majority of oligo(A), another ribonuclease resistant segment, is released together with most of the partially digested but still acid-precipitable single-stranded hnRNA and the hnRNP proteins not eluted by the ammonium sulfate alone. These special RNA regions appear to be tightly bound and may serve as points of attachment of the hnRNA to nuclear substructures. It is suggested that hnRNA metabolism does not take place in a soluble nucleoplasmic compartment but on organized structures firmly bound to the nuclear structure.
J Cell Biol 1978 Sep
PMID:Heterogeneous nuclear RNA-protein fibers in chromatin-depleted nuclei. 70 54


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