Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recombinant E(rns) glycoprotein of bovine viral diarrhoea virus (BVDV) has been tagged with a marker epitope or linked to an immunoglobulin Fc tail and expressed in insect and mammalian cell lines. The product was shown to be functional, both having ribonuclease activity and binding to a variety of cells that were permissive and non-permissive for replication of BVDV. Addition of soluble E(rns) to the medium blocked replication of BVDV in permissive cells. Binding of epitope-tagged E(rns) to permissive calf testes (CTe) cells was abolished and virus infection was reduced when cells were treated with heparinases I or III. E(rns) failed to bind to mutant Chinese hamster ovary (CHO) cells that lacked glycosaminoglycans (pgsA-745 cells) or heparan sulphate (pgsD-677 cells) but bound to normal CHO cells. E(rns) also bound to heparin immobilized on agarose and could be eluted by heparin and by a high concentration of salt. Flow cytometric analysis of E(rns) binding to CTe cell cultures showed that glycosaminoglycans such as heparin, fucoidan and dermatan sulphate all inhibit binding but dextran sulphate, keratan sulphate, chondroitin sulphate and mannan fail to inhibit binding. The low molecular mass polysulphonated inhibitor suramin also inhibited binding to CTe cells but poly-L-lysine did not. Furthermore, suramin, the suramin analogue CPD14, fucoidan and pentosan polysulphate inhibited the infectivity of virus. It is proposed that binding of E(rns) to cells is through an interaction with glycosaminoglycans and that BVDV may bind to cells initially through this interaction.
J Gen Virol 2000 Feb
PMID:Interactions of bovine viral diarrhoea virus glycoprotein E(rns) with cell surface glycosaminoglycans. 1064 44

Transgenic tobacco plants expressing an altered form of the 2a replicase gene from the Fny strain of Cucumber mosaic virus (CMV) exhibit suppressed virus replication and restricted virus movement when inoculated mechanically or by aphid vectors. Additional transformants have been generated which contain replicase gene constructs designed to determine the role(s) of transgene mRNA and/or protein in resistance. Resistance to systemic disease caused by CMV, as well as delayed infection, was observed in several lines of transgenic plants which were capable of expressing either full-length or truncated replicase proteins. In contrast, among plants which contained nontranslatable transgene constructs, only one of 61 lines examined exhibited delays or resistance. Once infected, plants never recovered, regardless of transgene translatability. Transgenic plants exhibiting a range of resistance levels were examined for transgene copy number, mRNA and protein levels. Although ribonuclease protection assays demonstrated that transgene mRNA levels were very low, resistant lines had consistently more steady-state transgene mRNA than susceptible lines. Furthermore, chlorotic or necrotic local lesions developed on the inoculated leaves of transgenic lines containing translatable transgenes, but not on inoculated leaves of lines containing nontranslatable transgenes. These results demonstrate that translatability of the transgene and possibly expression of the transgene protein itself facilitates replicase-mediated resistance to CMV in tobacco.
J Gen Virol 2000 Mar
PMID:Transgene translatability increases effectiveness of replicase-mediated resistance to cucumber mosaic virus. 1067 96

A second secreted ribonuclease, designated binase II, has been detected in Bacillus intermedius 7P, and its structural gene was cloned and sequenced. Unlike the well-known binase I, a 109-amino acid guanyl-specific enzyme, the 292-residue binase II is closely related to the B. subtilis nuclease Bsn, in structure and in its enzymatic properties. Binase II is also insensitive to inactivation by barstar, an inhibitor protein that is specific for guanyl-specific ribonucleases. While both B. intermedius enzymes are induced upon phosphate starvation, only the gene for binase I belongs to the pho regulon system and carries pho-box elements adjacent to its promoter sequence. The gene for binase II is similar to that for Bsn in lacking such elements. The birB gene coding for binase II appears to be located next to the 3'-end of a ferric ion transport operon, with which it convergently overlaps. This would allow attenuator control over binase II expression under conditions of starvation for ferric ions.
Mol Gen Genet 2000 May
PMID:A novel secreted ribonuclease from Bacillus intermedius: gene structure and regulatory control. 1085 77

Rta, mainly encoded by open reading frame 50 (ORF50), is the product of an immediate-early gene of human herpesvirus-8 (HHV-8)/Kaposi's sarcoma-associated herpesvirus. Rta is a transcriptional activator that is both necessary and sufficient to disrupt viral latency and activate the expression of downstream viral lytic genes. We report that ectopically expressed Rta protein could also activate the rta promoter on a reporter plasmid up to 144-fold, both in latently infected B cells and in uninfected epithelial cells, and that this activation was dose-dependent. Furthermore, by analysing the 5' untranslated region using ribonuclease protection assays, we demonstrated that transfection of an Rta expression plasmid into latently infected cells activated the expression of rta transcripts from endogenous viral genomes. We propose that auto-activation of the immediate-early gene, rta, is an important strategy for HHV-8 to effectively respond to environmental stimuli and maximally activate the virus lytic cycle.
J Gen Virol 2000 Dec
PMID:Auto-activation of the rta gene of human herpesvirus-8/Kaposi's sarcoma-associated herpesvirus. 1108 35

Under phosphate-deficient conditions, B. intermedius, B. pumilus, and B. thuringiensis secrete phosphohydrolases, including phosphomono-, phosphodiesterases, and guanyl-specific ribonucleases which cleave RNA molecules to nucleoside-3'-phosphatases. The enzymes are synthesized by phosphate-starved vegetative cells, which is not associated with sporulation. Using B. subtilis strains with mutation in the regulatory protein genes phoP and phoR, it was shown that these proteins regulate expression of B. intermedius, B. pumilus, and B. thuringiensis ribonuclease genes in B. subtilis cells. Genes of heterologous RNAses were activated in recombinant B. subtilis strains simultaneously with its own PHO regulon genes. Presumably a regulatory system homologous to B. subtilis two-component PhoP-PhoR signal transduction system functions in other representatives of the Bacillus genus.
Mol Gen Mikrobiol Virusol 2001
PMID:[Regulation of extracellular phosphohydrolase biosynthesis in bacilli]. 1144 94

Bovine viral diarrhoea virus (BVDV) envelope glycoprotein E(rns) interacts with highly sulphated heparin-like glycosaminoglycans (GAGs) located on the cell surface as an early step in virus infection of cells. Site-directed mutagenesis of recombinant E(rns) was undertaken and analysis of mutants by heparin-affinity chromatography and cell surface binding showed that a cluster of basic amino acids (480KKLENKSK487) near the C terminus of E(rns) was essential for binding. Mutants with amino acid substitutions of lysine residues 481 and 485 in E(rns) reduced the binding of E(rns) to immobilized heparin and cellular GAGs but retained ribonuclease activity. In contrast to normal E(rns), E(rns) that was unable to bind to cells also failed to inhibit BVDV infection of cells when the cells were pre-incubated with E(rns). It is proposed that the cluster of basic residues (480KKLENKSK487) localized at the C-terminal end of E(rns) constitutes a GAG-binding site.
J Gen Virol 2002 Sep
PMID:Identification of the glycosaminoglycan-binding site on the glycoprotein E(rns) of bovine viral diarrhoea virus by site-directed mutagenesis. 1218 68

We studied the seasonal variation of the expression of genes encoding the three native gonadotropin-releasing hormones (GnRHs), namely salmon(s) GnRH, chicken(c) GnRH-II, and seabream(sb) GnRH in red seabream, Pagrus (Chrysophrys) major, in order to better understand the regulatory mechanisms of GnRH gene expression by environmental and endocrine factors. Female red seabream, reared under natural conditions, were collected monthly or bimonthly from October to June, and the levels of the three distinct GnRH messenger ribonucleic acids (mRNAs) in the brains of those fish (n = 4-6) were determined by ribonuclease (RNase) protection analysis. The levels of sbGnRH mRNA correlated well with the observed ovarian histology; the levels of sbGnRH mRNA of immature fish in October and December were low, and increased in February and March in conjunction with active vitellogenesis. The sbGnRH mRNA levels reached a maximum level in April (spawning season), after which they rapidly decreased together with the observed ovarian regression in June. In contrast, the levels of sGnRH mRNA showed no variation, while those of cGnRH-II mRNA were elevated only slightly in March and April. The increase in sbGnRH mRNA levels correlates with the increase in day length, water temperature and serum steroids levels, suggesting that these factors are candidates for regulators of sbGnRH synthesis.
Gen Comp Endocrinol 2003 Feb 15
PMID:Seasonal variation of the three native gonadotropin-releasing hormone messenger ribonucleic acids levels in the brain of female red seabream. 1260 75

The objectives of this study were to characterize rainbow trout (Oncorhynchus mykiss) corticotropin-releasing factor (CRF) and neuropeptide Y (NPY) cDNAs and to determine their mRNA levels in response to social stress. Standard cloning techniques were used to obtain cDNAs, sequences for trout NPY and two CRF isoforms. At the predicted amino acid level, our NPY sequence differs from the trout amino acid sequence reported by. A phylogenetic analysis suggests that the two CRF isoforms result from a gene duplication that occurred in a common ancestor of salmonids. A tissue distribution demonstrated that the mRNAs of both CRF isoforms are predominantly present in the preoptic area of the trout brain, whereas NPY mRNA is more abundant in the telencephalon. Pairs of sized-matched juvenile female trout were allowed to interact for 72 h and social ranks were assigned on the basis of behavioural observations. Mean plasma cortisol levels were 13-fold higher in subordinate than in dominant trout. As measured by ribonuclease protection assay, CRF1 and NPY mRNA levels were respectively 51 and 32% higher in the preoptic area of subordinate trout; in addition, CRF1 and NPY mRNA levels were positively correlated (R2=0.44). These results suggest that subordinate rainbow trout chronically maintain high levels of CRF mRNA during social stress and that NPY may be involved in the control of the stress axis in trout.
Gen Comp Endocrinol 2003 Sep
PMID:Corticotropin-releasing factor and neuropeptide Y mRNA levels are elevated in the preoptic area of socially subordinate rainbow trout. 1292 15

1. The ribonucleoprotein of the microsome fraction which sediments at 40,000 R.P.M. as a pellet (and which is referred to as the pellet material) has been studied with reference to its role in protein synthesis in the pancreas. 2. In pellet material nucleic acid and protein form a definite complex as shown by its electrophoretic behavior and unchanging composition under various conditions. 3. Protein of pellet material is not especially rich in the diamino acids. 4. Evidence is brought forward indicating that the protein component of pellet material takes part in the general process of protein synthesis in the cell. (a) The well known correlation between quantity of RNA and rate of protein synthesis in a tissue implicates the protein of the pellet material, for most of the RNA in the pancreas and other tissues is in this material. (b) Uptake of isotopically labelled glycine by the pellet material, confirming results of previous workers, is for short periods greater than in other protein fractions. (c) Comparing the pellet materials of pancreas, liver, and kidney-three tissues with vastly different rates of protein synthesis, in the sequence given-there is a correlation between the quantity of RNA in the pellet and the rate of protein synthesis in the tissue; a similar correlation between quantity of RNA in the pellet material and rate of N(15)-glycine uptake by the protein component of the pellet; and finally, the level of uptake by total protein varies with the tissue and is related to the uptake of N(15)-glycine by protein of the pellet. 5. In the pancreas a distinction can be made between proteins synthesized for secretion and the nucleoprotein of the pellet (not found in the secretion) which, however, takes part in the synthetic process, as shown by the fact that the N(15) uptake by protein of the pellet is increased when the synthesis of digestive enzymes is stimulated by secretion. 6. The time course of N(15) uptake by proteins of the pancreas indicates that pellet protein serves as precursor material in the synthesis of the secretory proteins. 7. Rate of uptake of N(15)-glycine by the purines of RNA of the pellet material is not correlated with uptake by the protein. 8. The uptake of C(14)-alanine by an in vitro system of microsomes + mitochondria is impaired by preincubation of the microsomes with ribonuclease. This is direct experimental evidence for the dependence of protein synthesis upon the presence or intactness of ribonucleic acid in the microsomes.
J Gen Physiol 1953 Nov 20
PMID:Synthesis of protein in the pancreas. II. The role of ribonucleoprotein in protein synthesis. 1310 53

The effect of prolonged UV irradiation (mostly 2537 A) on the catalase activity of an aqueous yeast suspension was divisible into 4 periods. First, the period during which the cells lost their ability to form colonies, but during which no change in catalase activity was noted. Second, the period during which a considerable rise in catalase activity (Euler effect) occurred. The Euler effect was accompanied by enzyme alteration as shown by the simultaneous decrease in the activation energy of the enzyme-substrate system. However, during the initial phase of this period, as the catalase activity of the suspension began to increase, the activation energy rose to a transient level higher even than that characterizing the unaltered enzyme. Heat accelerated the rate of alteration when applied either during or after the irradiation; the activation energy for the over-all alteration reaction was 24 kcal., a value close to that recorded previously for alteration induced by chemical agents. Nevertheless, the rate-limiting step appeared to be different in the two cases. A model of these events was presented in which the primary photochemical action was on the site at which catalase is located within the cell. Third, a rather long period during which irradiation led to no diminution in the catalase activity of the maximally active suspension. This protection effect was duplicated in intro by a model crystalline catalase-KNA system, or by adding either ribonuclease digestion products of RNA or adenine to a catalase solution prior to irradiation. Evidence was adduced that the protection effect was not a simple screening, but involved some sort of interaction between the enzyme and the nitrogenous components of RNA, an interaction which must likewise occur within the cell. Alteration induced by CHCl(3) did not eliminate the protection effect, but that by butanol did. The onset of photoinactivation was due to modification of protein structure, not of RNA. Fourth, the period of photoinactivation of the intracellular enzyme, which was quite similar to that of the crystalline enzyme in vitro.
J Gen Physiol 1956 Sep 20
PMID:The action of ultraviolet radiation on yeast catalase. 1335 43


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