Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.5 (RNase)
 17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Simian virus 40 large tumor antigen was isolated by immunoaffinity chromatography from monkey or mouse cell cultures undergoing lytic or transforming infection. RNase-treated gel-purified large tumor antigen, on hydrolysis with alkali, gave about equimolar amounts of AMP, GMP, CMP, and UMP. Furthermore, RNA fragments of approximately 45 nucleotides could be isolated from large tumor antigen purified by the same procedure. Mapping of the T1 oligonucleotides showed a high complexity, as indicated by the presence of unique sequences of 15-30 nucleotides and of poly(A). This is compatible with the hypothesis that these RNA fragments are derived from cellular pre-mRNAs or mRNAs. Our results suggest that Simian virus 40 large tumor antigen is a RNA-binding protein and might possibly be involved in regulation of synthesis, maturation, or translation of cellular mRNAs.
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PMID:Simian virus 40 large tumor antigen: a "RNA binding protein"? 617 63

Adenylate kinase (ATP:AMP transphosphorylase) is a key enzyme in energy metabolism. The activity of its isoforms is subjected to multiple regulations. It is shown here that a specific fraction consisting of all adenylate kinase isoforms from tobacco leaves and tissue cultures does not bind to the anionic exchange-resin Mono Q. Sample pretreatment with ribonuclease could restore full binding to Mono Q, suggesting an association of adenylate kinase with RNA similar to the enzyme of Chenopodium rubrum (J. Chromatogr. 625: 13-19). We propose here that at least in vitro adenylate kinase can behave as an RNA-binding protein and that RNA-binding of adenylate kinase isoforms may be related to regulatory mechanisms.
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PMID:Binding of adenylate kinase to RNA. 750 29

An Arabidopsis cDNA (Atrbp33) encoding a nuclear-encoded chloroplast RNA-binding protein (RBP) has been isolated (A.J. DeLisle [1993] Plant Physiol 102: 313-314). ATRBP33 shares global structural homology with all known chloroplast RBPs: a chloroplast transit peptide in the amino terminus, followed by a unique acidic domain and a tandem pair of ribonucleoprotein consensus sequence-type RNA-binding domains in the carboxyl end. In vitro translation products of Atrbp33 were found to be imported into chloroplasts, suggesting that ATRBP33 is localized in chloroplasts. The expression of Atrbp33 was higher in chloroplast-containing organs than in nonchloroplast-containing organs. Furthermore, Atrbp33 was expressed in a light-dependent manner. These features are consistent with its postulated role in posttranscriptional control of chloroplast genes. Northern analyses and RNase protection assays showed that as many as nine messages are encoded by the single Atrbp33 gene. Sequence analysis of the cDNAs indicated that some of the transcripts have truncated 5' ends. Most interestingly, the multiple mRNAs potentially encode different polypeptides, one of which lacks a chloroplast transit peptide and acidic domain and contains only one intact RNA-binding domain. Unlike the chloroplast-localized ATRBP33, the truncated polypeptide may function in other cellular compartments.
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PMID:An Arabidopsis chloroplast RNA-binding protein gene encodes multiple mRNAs with different 5' ends. 797 18

The gene 8 product of SA11 rotavirus, NS35 (NSP2), is a nonspecific RNA-binding protein that accumulates in cytoplasmic inclusions (viroplasms) and is required for genome replication. To gain additional information on the role of NS35 in virus replication, lysates of simian rotavirus SA11-infected cells were treated with the thio-cleavable crosslinking agent, dithiobis(succinimidyl propionate) (DSP). Gel electrophoresis of NS35-specific immunoprecipitates recovered from the crosslinked lysates indicated that infected cells contained NS35 multimers, the largest consisting of four or more molecules of the protein. Sedimentation analysis of NS35 expressed in rabbit reticulocyte lysates by cell-free translation and in vTF7-3-infected cells by transfection with a gene 8-containing transcription vector showed that NS35 assembles into multimers of approximately 10S and that the formation of the multimers does not require other viral proteins. The 10S multimers were also detected in rotavirus-infected cells, providing evidence that they function in virus replication. The lack of RNase sensitivity indicates that the 10S multimers probably lack an RNA component. However, by an NS35-specific RNA capture assay, the multimers were shown to possess the RNA-binding activity previously demonstrated for NS35. Despite its ability to multimerize and bind RNA, indirect immunofluorescence assays showed that when transiently expressed in cells, NS35 alone is not sufficient to induce the formation of viroplasms. DSP-crosslinking of infected cell lysates and immunoprecipitation also revealed that NS35 interacts with the putative viral RNA polymerase VP1. Analysis of cytoplasmic extracts resolved by sedimentation on glycerol gradients suggested that the VP1-NS35 complexes are soluble and RNA-free. Complexes formed from NS35 multimers, VP1, and viral messenger RNA may function to coordinate RNA packaging and the assembly of viral cores.
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PMID:The rotavirus RNA-binding protein NS35 (NSP2) forms 10S multimers and interacts with the viral RNA polymerase. 803 Feb 43

Three cDNAs encoding RNA-binding proteins were isolated from a tobacco (Nicotiana sylvestris) cDNA library. The predicted proteins (RGP-1) are homologous to each other and consist of a consensus-sequence type RNA-binding domain of 80 amino acids in the N-terminal half and a glycine-rich domain of 61-78 amino acids in the C-terminal half. Nucleic acid-binding assay using the in vitro synthesized RGP-1 protein confirmed that it is an RNA-binding protein. Based on its strong affinity for poly(G) and poly(U), the RGP-1 proteins are suggested to bind specifically to G and/or U rich sequences. All three genes are expressed in leaves, roots, flowers and cultured cells, however, the substantial amount of pre-mRNAs are accumulated especially in roots. Sequence analysis and ribonuclease protection assay indicated that significant amounts of alternatively spliced mRNAs, which are produced by differential selection of 5' splice sites, are also present in various tissues. Tissue-specific alternative splicing was found in two of the three genes. The alternatively spliced mRNAs are also detected in polysomal fractions and are suggested to produce truncated polypeptides. A possible role of this alternative splicing is discussed.
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PMID:cDNA structure, expression and nucleic acid-binding properties of three RNA-binding proteins in tobacco: occurrence of tissue-specific alternative splicing. 837 74

EAP (EBER-associated protein) is an abundant, 15-kDa cellular RNA-binding protein which associates with certain herpesvirus small RNAs. We have raised polyclonal anti-EAP antibodies against a glutathione S-transferase-EAP fusion protein. Analysis of the RNA precipitated by these antibodies from Epstein-Barr virus (EBV)- or herpesvirus papio (HVP)-infected cells shows that > 95% of EBER 1 (EBV-encoded RNA 1) and the majority of HVP 1 (an HVP small RNA homologous to EBER 1) are associated with EAP. RNase protection experiments performed on native EBER 1 particles with affinity-purified anti-EAP antibodies demonstrate that EAP binds a stem-loop structure (stem-loop 3) of EBER 1. Since bacterially expressed glutathione S-transferase-EAP fusion protein binds EBER 1, we conclude that EAP binding is independent of any other cellular or viral protein. Detailed mutational analyses of stem-loop 3 suggest that EAP recognizes the majority of the nucleotides in this hairpin, interacting with both single-stranded and double-stranded regions in a sequence-specific manner. Binding studies utilizing EBER 1 deletion mutants suggest that there may also be a second, weaker EAP-binding site on stem-loop 4 of EBER 1. These data and the fact that stem-loop 3 represents the most highly conserved region between EBER 1 and HVP 1 suggest that EAP binding is a critical aspect of EBER 1 and HVP 1 function.
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PMID:The cellular RNA-binding protein EAP recognizes a conserved stem-loop in the Epstein-Barr virus small RNA EBER 1. 838 Feb 32

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

We have previously characterized a tobacco cDNA encoding a novel type RNA-binding protein (RZ-1), which contains a zinc finger motif in addition to a consensus sequence-type RNA-binding domain and is localized in the nucleus. Here we isolated its genomic clone from a Nicotiana sylvestris genomic library. Southern blot analysis suggested that RZ-1 is coded for by a single locus per haploid genome. Comparison of the cDNA and genomic sequences indicated that the RZ-1 gene contains two introns, one in the coding region and another in the 3'-untranslated region. RT-PCR and ribonuclease protection analyses showed that splicing of RZ-1 pre-mRNA occurs efficiently. The RZ-1 protein is actively synthesized in rapidly dividing tobacco cells, as demonstrated by immunoblot analysis.
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PMID:Structure and expression of the tobacco nuclear gene encoding RNA-binding protein RZ-1: the existence of an intron in the 3'-untranslated region. 880 57

The production of tumor necrosis factor alpha (TNF-alpha), a key proinflammatory cytokine essential for the function of the immune system, is regulated at both the transcriptional and posttranscriptional levels. In this report, we focus on the interaction of TNF-alpha mRNA with macrophage proteins, likely mediators of its post-transcriptional control. Mapping of murine TNF-alpha mRNA by using a combination of RNase protection and RNA gel shift assays revealed that two distinct sites within the 3' untranslated region (3'-UTR) engage in the formation of four major RNA-protein complexes, while no protein binding to the 5'-UTR or coding sequences was detected. The protein-binding site of three RNA-protein complexes, A, B, and C, is positioned between bases 1291 and 1320 inside the AU-rich sequence, a region previously shown to be crucial for both translational repression and lipopolysaccharide inducibility of TNF-alpha. An additional protein complex (complex D) whose binding to the TNF-alpha 3'-UTR was independent of the presence of AU-rich sequences was identified. At least six protein species with apparent molecular masses of 48, 52, 54, 81, 101, and 150 kDa are in direct contact with TNF-alpha mRNA. The RNA-binding proteins are differentially distributed in the cell: complexes A and D are present predominantly in the cytosol, while complexes B and C are found in the nucleus and associated with particulate cytoplasmic fractions. Cytosolic complex A displays comparatively high specificity for TNF-alpha mRNA, while the binding of complexes B and C to TNF-alpha mRNA is readily competed for by other AU-rich sequence-containing RNAs. In summary, these findings demonstrate that two regions of the TNF-alpha mRNA molecule interact with macrophage RNA-binding protein complexes that differ in their core protein composition, cellular distribution, and affinity to TNF-alpha mRNA.
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PMID:Two distinct regions in the 3' untranslated region of tumor necrosis factor alpha mRNA form complexes with macrophage proteins. 881 70

To better characterize the translational regulation of lipoprotein lipase (LPL) by epinephrine, cytoplasmic extracts were prepared from 3T3-L1 adipocytes, 3T3-F442A adipocytes, and other nonadipocyte cell lines (C2 cells, 3T3 fibroblasts, and Chinese hamster ovary cells). After treatment with epinephrine, cell extracts from the adipocytes inhibited LPL translation in an in vitro translation assay, whereas extracts from the C2 cells and 3T3 fibroblasts did not affect LPL translation. To identify the region on the LPL mRNA that controlled translation, in vitro translation was carried out using constructs containing different LPL sequences. Specific deletion of the first 50 (1601-1650) nucleotides of the 3' untranslated region (UTR) resulted in a loss of translation inhibition. The addition of LPL 3' UTR to a heterologous reporter gene construct resulted in an inhibition of translation. Inhibition of the reporter LPL 3' UTR translation was demonstrated by the addition of epinephrine-treated cell extracts to an in vitro translation assay, as well as by transfection of this construct into 3T3-F442A cells, followed by treatment of the cells with epinephrine. Competition for a trans-acting binding protein was demonstrated by the addition of sense mRNA strands corresponding to the proximal 135 nucleotides of the 3' UTR of LPL. To identify a RNA-binding protein, adipocyte extracts were incubated with 32P-labeled RNA sequences followed by RNase treatment. The epinephrine-treated cell extract protected a fragment of RNA when the RNA included sequences on the proximal 3' UTR of LPL. Cross-linking of this protected fragment and analysis by SDS-polyacrylamide gel electrophoresis revealed a protein that migrated at about 30 kDa. Thus, the addition of epinephrine to 3T3 adipocytes results in an inhibition of translation through the production of a RNA-binding protein that binds to a region on the proximal 3' UTR of the LPL mRNA.
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PMID:Translational regulation of lipoprotein lipase by epinephrine involves a trans-acting binding protein interacting with the 3' untranslated region. 899 67


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