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

Resistance to hormonal therapy is often a problem in the treatment of breast cancer patients. It has been suggested that resistance could be explained by altered nuclear hormone receptor or coregulator levels or inappropriately increased agonist activity of selective estrogen receptor modulator (SERM). To test these hypotheses, we have established novel MCF-7 cell line-derived in vitro models of anti-estrogen- and progestin-resistant and estrogen-independent breast cancer by long-term culture in the presence of toremifene and medroxyprogesterone acetate (MPA) and in the absence of estradiol, respectively. Using cell growth and multiprobe ribonuclease protection assays, the expression of 5 nuclear hormone receptors and 9 coregulators as well as the alterations in the cell proliferation and target gene transcription in response to hormonal treatments were studied. Progesterone receptor (PR) expression was decreased and silencing mediator for retinoid acid and thyroid hormone receptors (SMRT) and amplified in breast cancer-1 (AIB1) expression increased in anti-estrogen-resistant cells. Estrogen caused PR and ERbeta upregulation in all cell lines, but we did not observe increased agonist activity of anti-estrogen measured by regulation of these estrogen target genes. Basal ERalpha levels and estrogenic growth response were decreased and p300/CBP-associated factor (pCAF) and AIB1 upregulated by estrogen in progestin-resistant cells, but coregulator levels were unchanged. Estrogen-independent cells were still estrogen-responsive and PR, nuclear receptor corepressor (N-CoR) and SMRT expression was increased whereas steroid receptor coactivator-1 (SRC-1a) and CBP-related protein p300 (p300) expression decreased. Their growth was inhibited by toremifene, but estradiol was able to abrogate this effect, which might have interesting clinical implications concerning the use of postmenopausal hormone replacement therapy.
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PMID:Steroid hormone receptors and coregulators in endocrine-resistant and estrogen-independent breast cancer cells. 1615 93

A robust ribonuclease protection assay is described here. In brief, total cellular RNA, carrier yeast transfer RNA, and 32P-labeled antisense riboprobes, (one or more designed to detect the RNA species being studied and another to detect a suitable RNA species to act as a loading control) are combined and made 0.5 M with respect to ammonium acetate. Absolute alcohol (2.5 vol) is added, and tubes are incubated at -20 degrees C for 30 min. Precipitated RNA and riboprobes are pelleted by centrifugation and, after removal of the supernatants, dissolved in a small volume of hybridization buffer. After hybridization for 16 h at 55 degrees C, a ribonuclease cocktail is added to digest the unhybridized RNA. This is followed by a proteinase K digestion step that degrades the ribonucleases. Finally, the hybridized complex is precipitated at -20 degrees C using isopropanol:4 M guanidium thiocyanate (2:1), with added glycogen as a coprecipitant, and harvested by centrifugation. The pellet is dissolved in loading buffer, and the sample is electrophoresed in a polyacrylamide gel. The intensities of the bands in the gel representing the protected fragments for the target RNA and the loading control are quantitated by phosphorimager analysis.
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PMID:Quantitation of RNA by ribonuclease protection assay. 1649 11

Increases in phenylalanine ammonia lyase activity and pisatin synthesis were induced in excised pea pods (a) by basic polypeptides such as protamine, histone, lysozyme, cytochrome c, and ribonuclease; (b) by the polyamines spermine, spermidine, cadaverine, and putrescine, and (c) by the synthetic oligopeptides poly-l-lysine, poly-dl-ornithine, and poly-l-arginine.Poly-l-lysine (1 milligram per milliliter, molecular weight 7,200) was utilized as a model inducer of pisatin and phenylalanine ammonia lyase. The poly-l-lysine-induced responses could be inhibited by adding the RNA synthesis inhibitors cordycepin or alpha-amanitin to the pods prior to or at the time of inducer application. Cordycepin added 1.5 hours after inducer no longer completely inhibited induction. The application of poly-l-lysine was shown to characteristically change the rate of RNA synthesis within 30 minutes. Ultrastructural changes in pea nuclei were detected within 3 hours, and gross changes in nuclear morphology were apparent at 14 hours after inducer application. The physical appearance of uranyl acetate-stained chromatin isolated from poly-l-lysine 2 hours after inducer application differed from that of water-treated tissues. The template properties of chromatin extracted from pods 3 hours after inducer application were consistently superior to control chromatin when assayed with Escherichia coli RNA polymerase (without sigma factor). Chromatin from poly-l-lysine-induced tissue also bound 49% more actinomycin D-(3)H.The DNA-complexing properties of inducer compounds and the induced changes in the template and dye-binding properties of pea chromatin formed the basis for a proposed mode of action for phytoalexin induction.
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PMID:Mode of Pisatin Induction: Increased Template Activity and Dye-binding Capacity of Chromatin Isolated from Polypeptide-treated Pea Pods. 1665 52

A simple, sensitive, and rapid quantitative LC-MS/MS assay was designed for the simultaneous quantification of free and glycoprotein bound monosaccharides using a multiple reaction monitoring (MRM) approach. This study represents the first example of using LC-MS/MS methods to simultaneously quantify all common glycoprotein monosaccharides, including neutral and acidic monosaccharides. Sialic acids and reduced forms of neutral monosaccharides are efficiently separated using a porous graphitized carbon column. Neutral monosaccharide molecules are detected as their alditol acetate anion adducts [M + CH(3)CO(2)](-) using electrospray ionization in negative ion MRM mode, while sialic acids are detected as deprotonated ions [M - H](-). The new method exhibits very high sensitivity to carbohydrates with limits of detection as low as 1 pg for glucose, galactose, and mannose, and below 10 pg for other monosaccharides. The linearity of the described approach spans over three orders of magnitudes (pg to ng). The method effectively quantified monosaccharides originating from as little as 1 microg of fetuin, ribonuclease B, peroxidase, and alpha(1)-acid glycoprotein human (AGP) with results consistent with literature values and with independent CE-LIF measurements. The method is robust, rapid, and highly sensitive. It does not require derivatization or postcolumn addition of reagents.
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PMID:Multiple-reaction monitoring liquid chromatography mass spectrometry for monosaccharide compositional analysis of glycoproteins. 1931 80

The attempt has been made to determine the character of the basophile material that occurs normally in the cytoplasm of liver cells and accumulates in association with the hyperplasia of liver cells and of newly formed bile ducts when the azo dye butter yellow is administered to white rats. This substance in the normal liver cells, in the parenchymatous foci of basophile hyperplasia that are precursors of hepatomas, and in the hyperplastic basophile ducts that precede the cholangiomas produced by butter yellow has the characteristics of ribonucleic acid. It absorbs ultraviolet radiation of wave length 2537 A. It does not, like desoxyribonucleic acid, give the Feulgen reaction. It is removed from the cytoplasm by ribonuclease, and precipitation with lanthanum acetate protects it against the enzyme.
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PMID:LOCALIZATION OF RIBONUCLEIC ACID IN THE CYTOPLASM OF LIVER CELLS. 1987 49

Agricultural production is becoming increasingly dependent on the environmental factors that alter soil properties, plant productivity, and product quality. Environment pollution caused by heavy metals because of human activities are among the most dangerous pollutants on the biosphere. Here, we have studied the biochemical adaptation of wild and cultivated soybeans to the simulated effects of lead nitrate and lead acetate. Lead in the form of acetate had a relevant toxic effect, as evidenced by a significant increase in the concentration of malonic dialdehyde in the treated samples relative to control samples. Catalase and peroxidase, possibly performing a signaling function, are involved in the adaptation to the toxicity of Pb salts. The studied Pb salts showed a predominant stimulating effect on the specific activity of acid phosphatases in cultivated soybean, while the ribonuclease activity changed in both Glycine species. Moreover, in wild soybean, it was mostly suppressive, except for the first day. We found that the electrophoretic spectra of acid phosphatases of soybean seedlings was highly stabile, while that of ribonucleases varied depending on the salt. On the seventh day of exposure, lead nitrate caused a decrease in the specific activity of the studied hydrolases of seedlings of cultivated and wild soybeans. A change in the number or electrophoretic mobility of multiple forms of enzymes during treatment with Pb salts was revealed, which indicates the adaptation of the plants at the molecular genetic level. These results imply that the observed enzymes can be used as sensitive indicators for predicting the effects of heavy metals on soybean.
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PMID:Biochemical adaptation of wild and cultivated soybean against toxicity of lead salts. 3247 23

Bicarbonate (NaHCO3) stress was usually considered to be a mixed stress with salts and high pH. The NaHCO3-specific signaling in plants were rarely reported. In this study, transcriptome analyses was conducted in order to identify the NaHCO3-specific singling in Arabidopsis. Weighted correlation network analysis were performed to isolate the NaHCO3-specific modules in comparison to acetate treatment. The genes in the NaHCO3-root-specific module, which exhibited opposite expressions between NaHCO3 and sodium acetate treatments, were further examined with their corresponding knock-out mutants. The gene Exclusively Bicarbonate Sensitive 1 (EBS1) encoding an S-ribonuclease binding protein was identified to be specifically involved in plant tolerance to NaHCO3, but not to the other two alkaline salts, acetate and phosphate. We also identified the genes that commonly regulated by bicarbonate, acetate and phosphate. Multiple brassinosteroid associated gene ontology terms were enriched in these genes. Via genetic assays, it was found that brassinosteroid signaling positively regulated plant tolerance to NaHCO3 stress while negatively regulated tolerance to acetate and phosphate. Overall, our data genetically identified the bicarbonate-specific genes, and conclude that alkaline stress is mainly dependent on the specificities of the weak acid ions rather than high pH.
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PMID:An S-ribonuclease binding protein EBS1 and brassinolide signaling are specifically required for Arabidopsis tolerance to bicarbonate. 3316 37


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