Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.4 (ribonuclease)
 6,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

P40 is the protein encoded by the first open reading frame (ORF1) of the human LINE-1 (L1Hs) retrotransposon; it is 338 amino acids long, has a leucine zipper motif and has been found in human teratocarcinoma cell lines and some tumor cells. In this report, we describe properties of p40 in the human teratocarcinoma cell lines NTera2D1 and 2102Ep. The results indicate that: (i) most of p40 occurs in large multimeric cytoplasmic complexes, (ii) L1Hs RNA is associated with the p40 complexes, (iii) the complexes are dissociated by ribonuclease and (iv) p40 is a novel RNA-binding protein. Cross-linking experiments with full-length and truncated p40 produced in Escherichia coli also showed that: (i) p40 itself can form a multimeric complex larger than 250 kDa, (ii) the leucine zipper motif and the region conserved among the predicted ORF1 polypeptides of mammalian LINE-1s participate in complex formation and (iii) the amino terminal region is important for the stability of complex formation. Analysis of the amino acid sequence of p40 suggests that long segments of the molecule can assume an alpha-helical configuration including the leucine zipper and the conserved region. The evidence presented here suggests that the p40 complex is a ribonucleoprotein complex containing L1Hs RNA(s) and that protein-protein interactions in which alpha-helix structures participate, for example coiled-coils, may occur in the complex.
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PMID:Cytoplasmic ribonucleoprotein complexes containing human LINE-1 protein and RNA. 859 46

P40 is encoded by the first open reading frame of the human LINE-1 retrotransposon and is found in a large cytoplasmic ribonucleoprotein (RNP) complex, the p40 RNP-complex, in association with LINE-1 RNA(s) in human teratocarcinoma cell lines. We report here investigations on the stability of the p40 RNP-complex against various nucleases and high salt (0.5 M NaCl) treatment. The results indicate that (1) the p40 RNP-complex is dissociated after ribonuclease or high salt treatment, (2) DNase I does not disrupt the complex, (3) after dissociation of the complex, p40 maintain protein-protein interactions but in smaller complexes, and (4) p40 is not associated with the LINE-1 RNA(s) after high salt treatment. These observations suggest that the RNA molecule(s) is(are) essential for the stability of the large p40 complex and that the complex has a structure which allows various nucleases to reach the RNA. These features are distinct from those of typical virus and virus-like particles of retroviruses and other retrotransposons, respectively. Together with the fact that no significant sequence homology exists between p40 and the gag and gag-like proteins, it is likely that the p40 RNP-complex is structurally different from the typical virus and virus-like particles.
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PMID:Ribonuclease and high salt sensitivity of the ribonucleoprotein complex formed by the human LINE-1 retrotransposon. 930 51

A rapid multi-probe ribonuclease protection assay (RPA) was developed to quantitate equine-specific cytokine mRNA levels in activated equine monocyte-derived macrophages (EMDM) and equine peripheral blood mononuclear cells (EPBMC). Eleven template plasmids specific to 10 equine cytokine genes and the beta-actin gene were generated from which radiolabeled anti-sense RNA probes were produced. The multi-probe RPA simultaneously quantitated mRNA levels of equine IL-1alpha, IL-1beta, IL-6, IL-8, IL-10, IL-12 p35, IL-12 p40, IFN-gamma, TGF-1beta and TNF-alpha in EPBMC and EMDM with coefficients of variation as low as 0.03-0.08 (3-8%) when normalized to beta-actin expression. This sensitive and rapid assay provides a valuable tool for studies of equine immune responses.
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PMID:Simultaneous quantitation of equine cytokine mRNAs using a multi-probe ribonuclease protection assay. 1250 49

Neurocysticercosis is a parasitic infection of the human central nervous system caused by the cestode Taenia solium. The most common clinical manifestations of neurocysticercosis are seizures. Taenia crassiceps cysticercosis in mice has been used as an experimental model for T. solium cysticercosis. Granulomas surrounding murine cysticerci have striking immunopathological resemblance to human neurocysticercosis; early stage granulomas were able to induce seizures in a rodent model. To assess the role of proinflammatory cytokines in early stage granulomas, we isolated RNA from murine cysticercal granulomas and checked for cytokine expression by reverse transcriptase-polymerase chain reaction (RT-PCR) and/or ribonuclease (RNase) protection assays. Cytokine expression was compared with histological stages. Interleukin (IL)-1alpha, IL-1beta, IL-1 receptor antagonist, and tumor necrosis factor (TNF-alpha) were the major cytokines detected in all granulomas. Signals for IL-12, IL-18, and IL-6 RNA were not consistently detected and, when detected, were barely demonstrable. Expression of migration inhibitory factor (MIF), IL-6, IL-1alpha, TNF-alpha, and IL-18 was not significantly different between early and late-stage granulomas. Expression of IL-1beta, IL-1 receptor antagonist, and IL-12 p40 were higher in late, compared with early, stages. Thus, we demonstrated a broad range of cytokines in these granulomas. However, we did not document preferential expression of any proinflammatory cytokines in early stage granulomas. Thus, proinflammatory cytokines are not responsible for the seizures in the rodent model of neurocysticercosis.
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PMID:Proinflammatory cytokines in granulomas associated with murine cysticercosis are not the cause of seizures. 1699 90