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)

Treatment of rats with Cordycepin (3'-deoxyadenosine), an inhibitor of nuclear poly(A) synthesis, selectively decreased the energy and cytosol-dependent release of a portion of the mRNA species from the isolated hepatic nuclei in a cell-free system by approximately 40%. An analysis of the differential binding of the transported mRNA containing poly(A) tracts to nitrocellulose filters, and to cellulose or poly(U)-Sepharose columns suggested that the poly(A) tracts in the mRNA transported from the isolated hepatic nuclei of Cordycepin-treated rats, are decreased in size. This size decrease was confirmed through an analysis of the average size of the poly(A) tracts, released from the messengers by ribonuclease activity, on sucrose density gradients.
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PMID:Modified messenger ribonucleic acid release from isolated hepatic nuclei after inhibition of polyadenylate formation. 454 26

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