Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.13.1 (exoribonuclease)
 732 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Some biochemical characteristics of peritoneal macrophages, subcutaneous macrophages and subcutaneous cell populations containing multinucleate giant cells were compared. Subcutaneous macrophages possessed higher concentrations of succinate dehydrogenase, acid phosphatase, aryl hydroxylase, free RNase II, lecithin and free fatty acids than peritoneal macrophages, while the latter had higher concentrations of 5' -nucleotidase esterified cholesterol. These differences may be due to environmental variations depending on their anatomical position or more likely to their degree of activation. As significant numbers of multinucleate giant cells appear in the subcutaneous population the concentration aryl hydroxylase, 5' -nucleotidase lactate dehydrogenase, acid phosphatase, free ribonuclease II and esterified cholesterol falls. The concentration of succinate dehydrogenase decreases but then rises while the concentration of glucose-6-phosphate dehydrogenase increases. These highlight the differences between cell populations containing multinucleated giant cells and those composed from their precursor mononuclear phagocytes only.
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PMID:A biochemical profile of glass-adherent cell populations containing multinucleated foreign body giant cells. 78 24

The activities of the three known catabolic and the one anabolic polyadenylate enzymes have been determined in synchronized L5178y cells: endoribonuclease, exoribonuclease, 5'-nucleotidase and poly(A) polymerase (Mg2+-dependent). These four enzymes were found primarily in the nuclear fraction. The activity of poly(A) polymerase remains essentially constant during the transition from G1 to S phase. However, the poly(A) catabolic enzyme activities increase parallel with DNA synthesis; the endoribonuclease activity increases 4-fold during G1 to S phase, the exoribonuclease and the nucleotidase activities increasing 30-fold and 16-fold. During the S phase the poly(A)-degrading enzymes are far more active than the poly(A)-synthesizing activity of poly(A) polymerase. We conclude that in L5178y cells the poly(A)-degrading enzymes probably function in regulation of the post-transcriptional net-polyadenylation of heterogeneous nuclear RNA during the phase of DNA synthesis.
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PMID:Alterations of activities of ribonucleases and polyadenylate polymerase in synchronized mouse L cells. 89 26

The eukaryotic defense response posttranscriptional gene silencing (PTGS) is directed by short-interfering RNAs and thwarts invading nucleic acids via the RNA slicing activity of conserved ARGONAUTE (AGO) proteins. PTGS can be counteracted by exogenous or endogenous suppressors, including the cytoplasmic exoribonuclease XRN4, which also degrades microRNA (miRNA)-guided mRNA cleavage products but does not play an obvious role in development. Here, we show that the nuclear exoribonucleases XRN2 and XRN3 are endogenous PTGS suppressors. We also identify excised MIRNA loops as templates for XRN2 and XRN3 and show that XRN3 is critical for proper development. Independently, we identified the nucleotidase/phosphatase FIERY1 (FRY1) as an endogenous PTGS suppressor through a suppressor screen in a hypomorphic ago1 genetic background. FRY1 is one of six Arabidopsis thaliana orthologs of yeast Hal2. Yeast hal2 mutants overaccumulate 3'-phosphoadenosine 5'-phosphate, which suppresses the 5'-->3' exoribonucleases Xrn1 and Rat1. fry1 mutant plants recapitulate developmental and molecular characteristics of xrn mutants and likely restore PTGS in ago1 hypomorphic mutants by corepressing XRN2, XRN3, and XRN4, thus increasing RNA silencing triggers. We anticipate that screens incorporating partially compromised silencing components will uncover additional PTGS suppressors that may not be revealed using robust silencing systems.
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PMID:Arabidopsis FIERY1, XRN2, and XRN3 are endogenous RNA silencing suppressors. 1799 20

The Arabidopsis FIERY1 (FRY1) locus was originally identified as a negative regulator of stress-responsive gene expression and later shown to be required for suppression of RNA silencing. In this study we discovered that the FRY1 locus also regulates lateral root formation. Compared with the wild type, fry1 mutant seedlings generated significantly fewer lateral roots under normal growth conditions and also exhibited a dramatically reduced sensitivity to auxin in inducing lateral root initiation. Using transgenic plants that overexpress a yeast homolog of FRY1 that possesses only the 3', 5'-bisphosphate nucleotidase activity but not the inositol 1-phosphatase activity, we demonstrated that the lateral root phenotypes in fry1 result from loss of the nucleotidase activity. Furthermore, a T-DNA insertion mutant of another RNA silencing suppressor, XRN4 (but not XRN2 or XRN3), which is an exoribonuclease that is inhibited by the substrate of the FRY1 3', 5'-bisphosphate nucleotidase, exhibits similar lateral root defects. Although fry1 and xrn4 exhibited reduced sensitivity to ethylene, our experiments demonstrated that restoration of ethylene sensitivity in the fry1 mutant is not sufficient to rescue the lateral root phenotypes of fry1. Our results indicate that RNA silencing modulated by FRY1 and XRN4 plays an important role in shaping root architecture.
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PMID:The bifunctional abiotic stress signalling regulator and endogenous RNA silencing suppressor FIERY1 is required for lateral root formation. 2080 76