WorldWideScience

Sample records for nonsegmented negative-stranded rna

  1. Cellular La protein shields nonsegmented negative-strand RNA viral leader RNA from RIG-I and enhances virus growth by diverse mechanisms.

    Science.gov (United States)

    Bitko, Vira; Musiyenko, Alla; Bayfield, Mark A; Maraia, Richard J; Barik, Sailen

    2008-08-01

    The La antigen (SS-B) associates with a wide variety of cellular and viral RNAs to affect gene expression in multiple systems. We show that La is the major cellular protein found to be associated with the abundant 44-nucleotide viral leader RNA (leRNA) early after infection with respiratory syncytial virus (RSV), a nonsegmented negative-strand RNA virus. Consistent with this, La redistributes from the nucleus to the cytoplasm in RSV-infected cells. Upon RNA interference knockdown of La, leRNA is redirected to associate with the RNA-binding protein RIG-I, a known activator of interferon (IFN) gene expression, and this is accompanied by the early induction of IFN mRNA. These results suggest that La shields leRNA from RIG-I, abrogating the early viral activation of type I IFN. We mapped the leRNA binding function to RNA recognition motif 1 of La and showed that while wild-type La greatly enhanced RSV growth, a La mutant defective in RSV leRNA binding also did not support RSV growth. Comparative studies of RSV and Sendai virus and the use of IFN-negative Vero cells indicated that La supports the growth of nonsegmented negative-strand RNA viruses by both IFN suppression and a potentially novel IFN-independent mechanism.

  2. The nucleotide sequence of RNA1 of Lettuce big-vein virus, genus Varicosavirus, reveals its relation to nonsegmented negative-strand RNA viruses.

    Science.gov (United States)

    Sasaya, Takahide; Ishikawa, Koichi; Koganezawa, Hiroki

    2002-06-05

    The complete nucleotide sequence of RNA1 from Lettuce big-vein virus (LBVV), the type member of the genus Varicosavirus, was determined. LBVV RNA1 consists of 6797 nucleotides and contains one large ORF that encodes a large (L) protein of 2040 amino acids with a predicted M(r) of 232,092. Northern blot hybridization analysis indicated that the LBVV RNA1 is a negative-sense RNA. Database searches showed that the amino acid sequence of L protein is homologous to those of L polymerases of nonsegmented negative-strand RNA viruses. A cluster dendrogram derived from alignments of the LBVV L protein and the L polymerases indicated that the L protein is most closely related to the L polymerases of plant rhabdoviruses. Transcription termination/polyadenylation signal-like poly(U) tracts that resemble those in rhabdovirus and paramyxovirus RNAs were present upstream and downstream of the coding region. Although LBVV is related to rhabdoviruses, a key distinguishing feature is that the genome of LBVV is segmented. The results reemphasize the need to reconsider the taxonomic position of varicosaviruses.

  3. The RNA synthesis machinery of negative-stranded RNA viruses

    Energy Technology Data Exchange (ETDEWEB)

    Ortín, Juan, E-mail: jortin@cnb.csic.es [Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología (CSIC) and CIBER de Enfermedades Respiratorias (ISCIII), Madrid (Spain); Martín-Benito, Jaime, E-mail: jmartinb@cnb.csic.es [Department of Macromolecular Structures, Centro Nacional de Biotecnología (CSIC), Madrid (Spain)

    2015-05-15

    The group of Negative-Stranded RNA Viruses (NSVs) includes many human pathogens, like the influenza, measles, mumps, respiratory syncytial or Ebola viruses, which produce frequent epidemics of disease and occasional, high mortality outbreaks by transmission from animal reservoirs. The genome of NSVs consists of one to several single-stranded, negative-polarity RNA molecules that are always assembled into mega Dalton-sized complexes by association to many nucleoprotein monomers. These RNA-protein complexes or ribonucleoproteins function as templates for transcription and replication by action of the viral RNA polymerase and accessory proteins. Here we review our knowledge on these large RNA-synthesis machines, including the structure of their components, the interactions among them and their enzymatic activities, and we discuss models showing how they perform the virus transcription and replication programmes. - Highlights: • Overall organisation of NSV RNA synthesis machines. • Structure and function of the ribonucleoprotein components: Atomic structure of the RNA polymerase complex. • Commonalities and differences between segmented- and non-segmented NSVs. • Transcription versus replication programmes.

  4. The RNA synthesis machinery of negative-stranded RNA viruses

    International Nuclear Information System (INIS)

    Ortín, Juan; Martín-Benito, Jaime

    2015-01-01

    The group of Negative-Stranded RNA Viruses (NSVs) includes many human pathogens, like the influenza, measles, mumps, respiratory syncytial or Ebola viruses, which produce frequent epidemics of disease and occasional, high mortality outbreaks by transmission from animal reservoirs. The genome of NSVs consists of one to several single-stranded, negative-polarity RNA molecules that are always assembled into mega Dalton-sized complexes by association to many nucleoprotein monomers. These RNA-protein complexes or ribonucleoproteins function as templates for transcription and replication by action of the viral RNA polymerase and accessory proteins. Here we review our knowledge on these large RNA-synthesis machines, including the structure of their components, the interactions among them and their enzymatic activities, and we discuss models showing how they perform the virus transcription and replication programmes. - Highlights: • Overall organisation of NSV RNA synthesis machines. • Structure and function of the ribonucleoprotein components: Atomic structure of the RNA polymerase complex. • Commonalities and differences between segmented- and non-segmented NSVs. • Transcription versus replication programmes

  5. Strategies underlying RNA silencing suppression by negative strand RNA viruses

    NARCIS (Netherlands)

    Hemmes, J.C.

    2007-01-01

    The research described in this thesis focused on the strategies of negative strand RNA viruses to counteract antiviral RNA silencing. In plants and insects, RNA silencing has been shown to act as a sequence specific antiviral defence mechanism that is characterised by the processing of double

  6. Negative-strand RNA viruses: The plant-infecting counterparts

    NARCIS (Netherlands)

    Kormelink, R.J.M.; Garcia, M.L.; Goodin, M.; Sasaya, T.; Haenni, A.L.

    2011-01-01

    While a large number of negative-strand (-)RNA viruses infect animals and humans, a relative small number have plants as their primary host. Some of these have been classified within families together with animal/human infecting viruses due to similarities in particle morphology and genome

  7. Negative-strand RNA viruses: the plant-infecting counterparts.

    Science.gov (United States)

    Kormelink, Richard; Garcia, Maria Laura; Goodin, Michael; Sasaya, Takahide; Haenni, Anne-Lise

    2011-12-01

    While a large number of negative-strand (-)RNA viruses infect animals and humans, a relative small number have plants as their primary host. Some of these have been classified within families together with animal/human infecting viruses due to similarities in particle morphology and genome organization, while others have just recently been/or are still classified in floating genera. In most cases, at least two striking differences can still be discerned between the animal/human-infecting viruses and their plant-infecting counterparts which for the latter relate to their adaptation to plants as hosts. The first one is the capacity to modify plasmodesmata to facilitate systemic spread of infectious viral entities throughout the plant host. The second one is the capacity to counteract RNA interference (RNAi, also referred to as RNA silencing), the innate antiviral defence system of plants and insects. In this review an overview will be presented on the negative-strand RNA plant viruses classified within the families Bunyaviridae, Rhabdoviridae, Ophioviridae and floating genera Tenuivirus and Varicosavirus. Genetic differences with the animal-infecting counterparts and their evolutionary descendants will be described in light of the above processes. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Autophagy in Negative-Strand RNA Virus Infection

    Directory of Open Access Journals (Sweden)

    Yupeng Wang

    2018-02-01

    Full Text Available Autophagy is a homoeostatic process by which cytoplasmic material is targeted for degradation by the cell. Viruses have learned to manipulate the autophagic pathway to ensure their own replication and survival. Although much progress has been achieved in dissecting the interplay between viruses and cellular autophagic machinery, it is not well understood how the cellular autophagic pathway is utilized by viruses and manipulated to their own advantage. In this review, we briefly introduce autophagy, viral xenophagy and the interaction among autophagy, virus and immune response, then focus on the interplay between NS-RNA viruses and autophagy during virus infection. We have selected some exemplary NS-RNA viruses and will describe how these NS-RNA viruses regulate autophagy and the role of autophagy in NS-RNA viral replication and in immune responses to virus infection. We also review recent advances in understanding how NS-RNA viral proteins perturb autophagy and how autophagy-related proteins contribute to NS-RNA virus replication, pathogenesis and antiviral immunity.

  9. Role of the Pepino mosaic virus 3'-untranslated region elements in negative-strand RNA synthesis in vitro.

    Science.gov (United States)

    Osman, Toba A M; Olsthoorn, René C L; Livieratos, Ioannis C

    2014-09-22

    Pepino mosaic virus (PepMV) is a mechanically-transmitted positive-strand RNA potexvirus, with a 6410 nt long single-stranded (ss) RNA genome flanked by a 5'-methylguanosine cap and a 3' poly-A tail. Computer-assisted folding of the 64 nt long PepMV 3'-untranslated region (UTR) resulted in the prediction of three stem-loop structures (hp1, hp2, and hp3 in the 3'-5' direction). The importance of these structures and/or sequences for promotion of negative-strand RNA synthesis and binding to the RNA dependent RNA polymerase (RdRp) was tested in vitro using a specific RdRp assay. Hp1, which is highly variable among different PepMV isolates, appeared dispensable for negative-strand synthesis. Hp2, which is characterized by a large U-rich loop, tolerated base-pair changes in its stem as long as they maintained the stem integrity but was very sensitive to changes in the U-rich loop. Hp3, which harbours the conserved potexvirus ACUUAA hexamer motif, was essential for template activity. Template-RNA polymerase binding competition experiments showed that the ACUUAA sequence represents a high-affinity RdRp binding element. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Phenotypic silencing of cytoplasmic genes using sequence-specific double-stranded short interfering RNA and its application in the reverse genetics of wild type negative-strand RNA viruses

    Directory of Open Access Journals (Sweden)

    Barik Sailen

    2001-12-01

    Full Text Available Abstract Background Post-transcriptional gene silencing (PTGS by short interfering RNA has opened up new directions in the phenotypic mutation of cellular genes. However, its efficacy on non-nuclear genes and its effect on the interferon pathway remain unexplored. Since directed mutation of RNA genomes is not possible through conventional mutagenesis, we have tested sequence-specific 21-nucleotide long double-stranded RNAs (dsRNAs for their ability to silence cytoplasmic RNA genomes. Results Short dsRNAs were generated against specific mRNAs of respiratory syncytial virus, a nonsegmented negative-stranded RNA virus with a cytoplasmic life cycle. At nanomolar concentrations, the dsRNAs specifically abrogated expression of the corresponding viral proteins, and produced the expected mutant phenotype ex vivo. The dsRNAs did not induce an interferon response, and did not inhibit cellular gene expression. The ablation of the viral proteins correlated with the loss of the specific mRNAs. In contrast, viral genomic and antigenomic RNA, which are encapsidated, were not directly affected. Conclusions Synthetic inhibitory dsRNAs are effective in specific silencing of RNA genomes that are exclusively cytoplasmic and transcribed by RNA-dependent RNA polymerases. RNA-directed RNA gene silencing does not require cloning, expression, and mutagenesis of viral cDNA, and thus, will allow the generation of phenotypic null mutants of specific RNA viral genes under normal infection conditions and at any point in the infection cycle. This will, for the first time, permit functional genomic studies, attenuated infections, reverse genetic analysis, and studies of host-virus signaling pathways using a wild type RNA virus, unencumbered by any superinfecting virus.

  11. RNA-dependent RNA polymerase of hepatitis C virus binds to its coding region RNA stem-loop structure, 5BSL3.2, and its negative strand.

    Science.gov (United States)

    Kanamori, Hiroshi; Yuhashi, Kazuhito; Ohnishi, Shin; Koike, Kazuhiko; Kodama, Tatsuhiko

    2010-05-01

    The hepatitis C virus NS5B RNA-dependent RNA polymerase (RdRp) is a key enzyme involved in viral replication. Interaction between NS5B RdRp and the viral RNA sequence is likely to be an important step in viral RNA replication. The C-terminal half of the NS5B-coding sequence, which contains the important cis-acting replication element, has been identified as an NS5B-binding sequence. In the present study, we confirm the specific binding of NS5B to one of the RNA stem-loop structures in the region, 5BSL3.2. In addition, we show that NS5B binds to the complementary strand of 5BSL3.2 (5BSL3.2N). The bulge structure of 5BSL3.2N was shown to be indispensable for tight binding to NS5B. In vitro RdRp activity was inhibited by 5BSL3.2N, indicating the importance of the RNA element in the polymerization by RdRp. These results suggest the involvement of the RNA stem-loop structure of the negative strand in the replication process.

  12. Molecular Mechanisms of Innate Immune Inhibition by Non-Segmented Negative-Sense RNA Viruses

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Srirupa; Basler, Christopher F.; Amarasinghe, Gaya K.; Leung, Daisy W.

    2016-08-01

    The host innate immune system serves as the first line of defense against viral infections. Germline-encoded pattern recognition receptors detect molecular patterns associated with pathogens and activate innate immune responses. Of particular relevance to viral infections are those pattern recognition receptors that activate type I interferon responses, which establish an antiviral state. The order Mononegavirales is composed of viruses that possess single-stranded, non-segmented negative-sense (NNS) RNA genomes and are important human pathogens that consistently antagonize signaling related to type I interferon responses. NNS viruses have limited encoding capacity compared to many DNA viruses, and as a likely consequence, most open reading frames encode multifunctional viral proteins that interact with host factors in order to evade host cell defenses while promoting viral replication. In this review, we will discuss the molecular mechanisms of innate immune evasion by select NNS viruses. A greater understanding of these interactions will be critical in facilitating the development of effective therapeutics and viral countermeasures.

  13. Identification of cis-acting elements on positive-strand subgenomic mRNA required for the synthesis of negative-strand counterpart in bovine coronavirus.

    Science.gov (United States)

    Yeh, Po-Yuan; Wu, Hung-Yi

    2014-07-30

    It has been demonstrated that, in addition to genomic RNA, sgmRNA is able to serve as a template for the synthesis of the negative-strand [(-)-strand] complement. However, the cis-acting elements on the positive-strand [(+)-strand] sgmRNA required for (-)-strand sgmRNA synthesis have not yet been systematically identified. In this study, we employed real-time quantitative reverse transcription polymerase chain reaction to analyze the cis-acting elements on bovine coronavirus (BCoV) sgmRNA 7 required for the synthesis of its (-)-strand counterpart by deletion mutagenesis. The major findings are as follows. (1) Deletion of the 5'-terminal leader sequence on sgmRNA 7 decreased the synthesis of the (-)-strand sgmRNA complement. (2) Deletions of the 3' untranslated region (UTR) bulged stem-loop showed no effect on (-)-strand sgmRNA synthesis; however, deletion of the 3' UTR pseudoknot decreased the yield of (-)-strand sgmRNA. (3) Nucleotides positioned from -15 to -34 of the sgmRNA 7 3'-terminal region are required for efficient (-)-strand sgmRNA synthesis. (4) Nucleotide species at the 3'-most position (-1) of sgmRNA 7 is correlated to the efficiency of (-)-strand sgmRNA synthesis. These results together suggest, in principle, that the 5'- and 3'-terminal sequences on sgmRNA 7 harbor cis-acting elements are critical for efficient (-)-strand sgmRNA synthesis in BCoV.

  14. Identification of Cis-Acting Elements on Positive-Strand Subgenomic mRNA Required for the Synthesis of Negative-Strand Counterpart in Bovine Coronavirus

    Directory of Open Access Journals (Sweden)

    Po-Yuan Yeh

    2014-07-01

    Full Text Available It has been demonstrated that, in addition to genomic RNA, sgmRNA is able to serve as a template for the synthesis of the negative-strand [(−-strand] complement. However, the cis-acting elements on the positive-strand [(+-strand] sgmRNA required for (−-strand sgmRNA synthesis have not yet been systematically identified. In this study, we employed real-time quantitative reverse transcription polymerase chain reaction to analyze the cis-acting elements on bovine coronavirus (BCoV sgmRNA 7 required for the synthesis of its (−-strand counterpart by deletion mutagenesis. The major findings are as follows. (1 Deletion of the 5'-terminal leader sequence on sgmRNA 7 decreased the synthesis of the (−-strand sgmRNA complement. (2 Deletions of the 3' untranslated region (UTR bulged stem-loop showed no effect on (−-strand sgmRNA synthesis; however, deletion of the 3' UTR pseudoknot decreased the yield of (−-strand sgmRNA. (3 Nucleotides positioned from −15 to −34 of the sgmRNA 7 3'-terminal region are required for efficient (−-strand sgmRNA synthesis. (4 Nucleotide species at the 3'-most position (−1 of sgmRNA 7 is correlated to the efficiency of (−-strand sgmRNA synthesis. These results together suggest, in principle, that the 5'- and 3'-terminal sequences on sgmRNA 7 harbor cis-acting elements are critical for efficient (−-strand sgmRNA synthesis in BCoV.

  15. The first phlebo-like virus infecting plants: a case study on the adaptation of negative-stranded RNA viruses to new hosts.

    Science.gov (United States)

    Navarro, Beatriz; Minutolo, Maria; De Stradis, Angelo; Palmisano, Francesco; Alioto, Daniela; Di Serio, Francesco

    2018-05-01

    A novel negative-stranded (ns) RNA virus associated with a severe citrus disease reported more than 80 years ago has been identified. Transmission electron microscopy showed that this novel virus, tentatively named citrus concave gum-associated virus, is flexuous and non-enveloped. Notwithstanding, its two genomic RNAs share structural features with members of the genus Phlebovirus, which are enveloped arthropod-transmitted viruses infecting mammals, and with a group of still unclassified phlebo-like viruses mainly infecting arthropods. CCGaV genomic RNAs code for an RNA-dependent RNA polymerase, a nucleocapsid protein and a putative movement protein showing structural and phylogenetic relationships with phlebo-like viruses, phleboviruses and the unrelated ophioviruses, respectively, thus providing intriguing evidence of a modular genome evolution. Phylogenetic reconstructions identified an invertebrate-restricted virus as the most likely ancestor of this virus, revealing that its adaptation to plants was independent from and possibly predated that of the other nsRNA plant viruses. These data are consistent with an evolutionary scenario in which trans-kingdom adaptation occurred several times during the history of nsRNA viruses and followed different evolutionary pathways, in which genomic RNA segments were gained or lost. The need to create a new genus for this bipartite nsRNA virus and the impact of the rapid and specific detection methods developed here on citrus sanitation and certification are also discussed. © 2017 BSPP AND JOHN WILEY & SONS LTD.

  16. Plant rhabdoviruses: new insights and research needs in the interplay of negative-strand RNA viruses with plant and insect hosts.

    Science.gov (United States)

    Mann, Krin S; Dietzgen, Ralf G

    2014-08-01

    Rhabdoviruses are taxonomically classified in the family Rhabdoviridae, order Mononegavirales. As a group, rhabdoviruses can infect plants, invertebrates and vertebrates. Plant cyto- and nucleorhabdoviruses infect a wide variety of species across both monocot and dicot families, including agriculturally important crops such as lettuce, wheat, barley, rice, maize, potato and tomato. Plant rhabdoviruses are transmitted by and replicate in hemipteran insects such as aphids (Aphididae), leafhoppers (Cicadellidae), or planthoppers (Delphacidae). These specific interactions between plants, viruses and insects offer new insights into host adaptation and molecular virus evolution. This review explores recent advances as well as knowledge gaps in understanding of replication, RNA silencing suppression and movement of plant rhabdoviruses with respect to both plant and insect hosts.

  17. Viral RNA polymerase scanning and the gymnastics of Sendai virus RNA synthesis

    International Nuclear Information System (INIS)

    Kolakofsky, Daniel; Le Mercier, Philippe; Iseni, Frederic; Garcin, Dominique

    2004-01-01

    mRNA synthesis from nonsegmented negative-strand RNA virus (NNV) genomes is unique in that the genome RNA is embedded in an N protein assembly (the nucleocapsid) and the viral RNA polymerase does not dissociate from the template after release of each mRNA, but rather scans the genome RNA for the next gene-start site. A revised model for NNV RNA synthesis is presented, in which RNA polymerase scanning plays a prominent role. Polymerase scanning of the template is known to occur as the viral transcriptase negotiates gene junctions without falling off the template

  18. The evolution of RNA viruses: A population genetics view

    Science.gov (United States)

    Moya, Andrés; Elena, Santiago F.; Bracho, Alma; Miralles, Rosario; Barrio, Eladio

    2000-01-01

    RNA viruses are excellent experimental models for studying evolution under the theoretical framework of population genetics. For a proper justification of this thesis we have introduced some properties of RNA viruses that are relevant for studying evolution. On the other hand, population genetics is a reductionistic theory of evolution. It does not consider or make simplistic assumptions on the transformation laws within and between genotypic and phenotypic spaces. However, such laws are minimized in the case of RNA viruses because the phenotypic space maps onto the genotypic space in a much more linear way than on higher DNA-based organisms. Under experimental conditions, we have tested the role of deleterious and beneficial mutations in the degree of adaptation of vesicular stomatitis virus (VSV), a nonsegmented virus of negative strand. We also have studied how effective population size, initial genetic variability in populations, and environmental heterogeneity shapes the impact of mutations in the evolution of vesicular stomatitis virus. Finally, in an integrative attempt, we discuss pros and cons of the quasispecies theory compared with classic population genetics models for haploid organisms to explain the evolution of RNA viruses. PMID:10860958

  19. 3′-Terminal Sequence in Poliovirus Negative-Strand Templates Is the Primary cis-Acting Element Required for VPgpUpU-Primed Positive-Strand Initiation

    OpenAIRE

    Sharma, Nidhi; O'Donnell, Brian J.; Flanegan, James B.

    2005-01-01

    The 5′ cloverleaf in poliovirus RNA has a direct role in regulating the stability, translation, and replication of viral RNA. In this study, we investigated the role of stem a in the 5′ cloverleaf in regulating the stability and replication of poliovirus RNA in HeLa S10 translation-replication reactions. Our results showed that disrupting the duplex structure of stem a destabilized viral RNA and inhibited efficient negative-strand synthesis. Surprisingly, the duplex structure of stem a was no...

  20. RNA binding specificity of Ebola virus transcription factor VP30.

    Science.gov (United States)

    Schlereth, Julia; Grünweller, Arnold; Biedenkopf, Nadine; Becker, Stephan; Hartmann, Roland K

    2016-09-01

    The transcription factor VP30 of the non-segmented RNA negative strand Ebola virus balances viral transcription and replication. Here, we comprehensively studied RNA binding by VP30. Using a novel VP30:RNA electrophoretic mobility shift assay, we tested truncated variants of 2 potential natural RNA substrates of VP30 - the genomic Ebola viral 3'-leader region and its complementary antigenomic counterpart (each ∼155 nt in length) - and a series of other non-viral RNAs. Based on oligonucleotide interference, the major VP30 binding region on the genomic 3'-leader substrate was assigned to the internal expanded single-stranded region (∼ nt 125-80). Best binding to VP30 was obtained with ssRNAs of optimally ∼ 40 nt and mixed base composition; underrepresentation of purines or pyrimidines was tolerated, but homopolymeric sequences impaired binding. A stem-loop structure, particularly at the 3'-end or positioned internally, supports stable binding to VP30. In contrast, dsRNA or RNAs exposing large internal loops flanked by entirely helical arms on both sides are not bound. Introduction of a 5´-Cap(0) structure impaired VP30 binding. Also, ssDNAs bind substantially weaker than isosequential ssRNAs and heparin competes with RNA for binding to VP30, indicating that ribose 2'-hydroxyls and electrostatic contacts of the phosphate groups contribute to the formation of VP30:RNA complexes. Our results indicate a rather relaxed RNA binding specificity of filoviral VP30, which largely differs from that of the functionally related transcription factor of the Paramyxoviridae which binds to ssRNAs as short as 13 nt with a preference for oligo(A) sequences.

  1. 5'-Phospho-RNA Acceptor Specificity of GDP Polyribonucleotidyltransferase of Vesicular Stomatitis Virus in mRNA Capping.

    Science.gov (United States)

    Ogino, Minako; Ogino, Tomoaki

    2017-03-15

    The GDP polyribonucleotidyltransferase (PRNTase) domain of the multifunctional L protein of rhabdoviruses, such as vesicular stomatitis virus (VSV) and rabies virus, catalyzes the transfer of 5'-phospho-RNA (pRNA) from 5'-triphospho-RNA (pppRNA) to GDP via a covalent enzyme-pRNA intermediate to generate a 5'-cap structure (GpppA). Here, using an improved oligo-RNA capping assay with the VSV L protein, we showed that the Michaelis constants for GDP and pppAACAG (VSV mRNA-start sequence) are 0.03 and 0.4 μM, respectively. A competition assay between GDP and GDP analogues in the GpppA formation and pRNA transfer assay using GDP analogues as pRNA acceptors indicated that the PRNTase domain recognizes the C-2-amino group, but not the C-6-oxo group, N-1-hydrogen, or N-7-nitrogen, of GDP for the cap formation. 2,6-Diaminopurine-riboside (DAP), 7-deazaguanosine (7-deaza-G), and 7-methylguanosine (m 7 G) diphosphates efficiently accepted pRNA, resulting in the formation of DAPpppA, 7-deaza-GpppA, and m 7 GpppA (cap 0), respectively. Furthermore, either the 2'- or 3'-hydroxyl group of GDP was found to be required for efficient pRNA transfer. A 5'-diphosphate form of antiviral ribavirin weakly inhibited the GpppA formation but did not act as a pRNA acceptor. These results indicate that the PRNTase domain has a unique guanosine-binding mode different from that of eukaryotic mRNA capping enzyme, guanylyltransferase. IMPORTANCE mRNAs of nonsegmented negative-strand (NNS) RNA viruses, such as VSV, possess a fully methylated cap structure, which is required for mRNA stability, efficient translation, and evasion of antiviral innate immunity in host cells. GDP polyribonucleotidyltransferase (PRNTase) is an unconventional mRNA capping enzyme of NNS RNA viruses that is distinct from the eukaryotic mRNA capping enzyme, guanylyltransferase. In this study, we studied the pRNA acceptor specificity of VSV PRNTase using various GDP analogues and identified chemical groups of GDP as

  2. 5′-Phospho-RNA Acceptor Specificity of GDP Polyribonucleotidyltransferase of Vesicular Stomatitis Virus in mRNA Capping

    Science.gov (United States)

    Ogino, Minako

    2017-01-01

    ABSTRACT The GDP polyribonucleotidyltransferase (PRNTase) domain of the multifunctional L protein of rhabdoviruses, such as vesicular stomatitis virus (VSV) and rabies virus, catalyzes the transfer of 5′-phospho-RNA (pRNA) from 5′-triphospho-RNA (pppRNA) to GDP via a covalent enzyme-pRNA intermediate to generate a 5′-cap structure (GpppA). Here, using an improved oligo-RNA capping assay with the VSV L protein, we showed that the Michaelis constants for GDP and pppAACAG (VSV mRNA-start sequence) are 0.03 and 0.4 μM, respectively. A competition assay between GDP and GDP analogues in the GpppA formation and pRNA transfer assay using GDP analogues as pRNA acceptors indicated that the PRNTase domain recognizes the C-2-amino group, but not the C-6-oxo group, N-1-hydrogen, or N-7-nitrogen, of GDP for the cap formation. 2,6-Diaminopurine-riboside (DAP), 7-deazaguanosine (7-deaza-G), and 7-methylguanosine (m7G) diphosphates efficiently accepted pRNA, resulting in the formation of DAPpppA, 7-deaza-GpppA, and m7GpppA (cap 0), respectively. Furthermore, either the 2′- or 3′-hydroxyl group of GDP was found to be required for efficient pRNA transfer. A 5′-diphosphate form of antiviral ribavirin weakly inhibited the GpppA formation but did not act as a pRNA acceptor. These results indicate that the PRNTase domain has a unique guanosine-binding mode different from that of eukaryotic mRNA capping enzyme, guanylyltransferase. IMPORTANCE mRNAs of nonsegmented negative-strand (NNS) RNA viruses, such as VSV, possess a fully methylated cap structure, which is required for mRNA stability, efficient translation, and evasion of antiviral innate immunity in host cells. GDP polyribonucleotidyltransferase (PRNTase) is an unconventional mRNA capping enzyme of NNS RNA viruses that is distinct from the eukaryotic mRNA capping enzyme, guanylyltransferase. In this study, we studied the pRNA acceptor specificity of VSV PRNTase using various GDP analogues and identified chemical groups

  3. A combined segmenting and non-segmenting approach to signal quality estimation for ambulatory photoplethysmography

    International Nuclear Information System (INIS)

    Wander, J D; Morris, D

    2014-01-01

    Continuous cardiac monitoring of healthy and unhealthy patients can help us understand the progression of heart disease and enable early treatment. Optical pulse sensing is an excellent candidate for continuous mobile monitoring of cardiovascular health indicators, but optical pulse signals are susceptible to corruption from a number of noise sources, including motion artifact. Therefore, before higher-level health indicators can be reliably computed, corrupted data must be separated from valid data. This is an especially difficult task in the presence of artifact caused by ambulation (e.g. walking or jogging), which shares significant spectral energy with the true pulsatile signal. In this manuscript, we present a machine-learning-based system for automated estimation of signal quality of optical pulse signals that performs well in the presence of periodic artifact. We hypothesized that signal processing methods that identified individual heart beats (segmenting approaches) would be more error-prone than methods that did not (non-segmenting approaches) when applied to data contaminated by periodic artifact. We further hypothesized that a fusion of segmenting and non-segmenting approaches would outperform either approach alone. Therefore, we developed a novel non-segmenting approach to signal quality estimation that we then utilized in combination with a traditional segmenting approach. Using this system we were able to robustly detect differences in signal quality as labeled by expert human raters (Pearson’s r = 0.9263). We then validated our original hypotheses by demonstrating that our non-segmenting approach outperformed the segmenting approach in the presence of contaminated signal, and that the combined system outperformed either individually. Lastly, as an example, we demonstrated the utility of our signal quality estimation system in evaluating the trustworthiness of heart rate measurements derived from optical pulse signals. (paper)

  4. Short distance movement of genomic negative strands in a host and nonhost for Sugarcane mosaic virus (SCMV

    Directory of Open Access Journals (Sweden)

    Hernández-Vela Juan

    2011-01-01

    Full Text Available Abstract Background In order to obtain an initial and preliminary understanding of host and nonhost resistance in the initial step of potyvirus replication, both positive and negative Sugarcane mosaic virus (SCMV strands where traced in inoculated and systemic leaves in host and nonhost resistant maize and sugarcane for one Mexican potyviral isolate (SCMV-VER1. Intermediary replication forms, such as the negative viral strand, seem to only move a short distance as surveyed by RT-PCR analysis and ELISA in different leaves. Virus purification was also done in leaves and stems. Results Susceptible maize plants allowed for viral SCMV replication, cell-to-cell, and long distance movement, as indicated by the presence of the coat protein along the plant. In the host resistant maize plants for the SCMV-VER1 isolate, the virus was able to establish the disease though the initial steps of virus replication, as detected by the presence of negative strands, in the basal area of the inoculated leaves at six and twelve days post inoculation. The nonhost sugarcane for SCMV-VER1 and the host sugarcane for SCMV-CAM6 also allowed the initial steps of viral replication for the VER1 isolate in the local inoculated leaf. SCMV-VER1 virions could be extracted from stems of susceptible maize with higher titers than leaves. Conclusion Nonhost and host resistance allow the initial steps of potyvirus SCMV replication, as shown by the negative strands' presence. Furthermore, both hosts allow the negative viral strands' local movement, but not their systemic spread through the stem. The presence of larger amounts of extractable virions from the stem (as compared to the leaves in susceptible maize lines suggests their long distance movement as assembled particles. This will be the first report suggesting the long distance movement of a monocot potyvirus as a virion.

  5. Tospovirus : induction and suppression of RNA silencing

    NARCIS (Netherlands)

    Hedil, Marcio

    2016-01-01

    While infecting their hosts, viruses must deal with host immunity. In plants the antiviral RNA silencing pathway is an important part of plant innate immunity. Tospoviruses are segmented negative-stranded RNA viruses of plants. To counteract the antiviral RNA silencing response in plants,

  6. Epithelial Distribution and Replication of Foot-and-Mouth Disease Virus RNA in Infected Pigs

    DEFF Research Database (Denmark)

    Durand, S.; Murphy, C.; Zhang, Z.

    2008-01-01

    experimentally with FMDV serotype O UKG 34/2001 and tissue samples were collected from I to 4 clays post-infection. Samples were stored at -70 degrees C and frozen sections were prepared for in-situ hybridization (ISH). A digoxigenin-labelled RNA probe complementary to a coding part of the RNA-dependent RNA...... negative strand RNA was observed in basal cells above the basement membrane and along the dermal papillae. The basal cells therefore demonstrate the highest signal for detection of the FMDV positive and negative strand RNAs in both tongue and foot epithelium. These novel results Suggest that the epithelial...

  7. Rational design of avian metapneumovirus live attenuated vaccines by inhibiting viral messenger RNA cap methyltransferase

    Science.gov (United States)

    Avian metapneumovirus (aMPV), also known as avian pneumovirus or turkey rhinotracheitis, is a non-segmented negative-sense RNA virus belonging to the family of Paramyxoviridae, the subfamily Pneumovirinae, and the genus Metapneumovirus. aMPV is the causative agent of respiratory tract infection and ...

  8. RNA.

    Science.gov (United States)

    Darnell, James E., Jr.

    1985-01-01

    Ribonucleic acid (RNA) converts genetic information into protein and usually must be processed to serve its function. RNA types, chemical structure, protein synthesis, translation, manufacture, and processing are discussed. Concludes that the first genes might have been spliced RNA and that humans might be closer than bacteria to primitive…

  9. Mechanism of Telomerase Inhibition Using a Small Inhibitory RNAs and Induction of Breast Tumor Cell Sensitization

    Science.gov (United States)

    2007-04-01

    immunoprecipitation; TnT- transcription and translation. References Cited Barik , S. 2004. Control of nonsegmented negative-strand RNA virus replication by siRNA...Virus Res. 102: 27-35. Barquinero, J . et al. 2004. Retroviral vectors: new applications for an old tool. Gene Ther. 11(suppl 1): S3-S9...proteins and heterochromatin. Oncogene. 21: 553-563. Chen, J -L., Blasco, M.A., and Greider, C.W. 2000. Secondary structure of vertebrate telomerase RNA

  10. Preparation and characterization of high-specific activity radiolabeled 50 S measles virus RNA

    International Nuclear Information System (INIS)

    Spruance, S.L.; Ashton, B.N.; Smith, C.B.

    1980-01-01

    A method is described to radiolabeled measles virus RNA for hybridization studies. Tritiated nucleosides were added to the media of measles virus infected Vero cells and negative-strand (genome) RNA with a specific activity of 6X10 5 c.p.m./μg was purified from viral nucleocapsids. 50 S RNA was the sole RNA present in nucleocapsids and self-annealed to 50% due to the presence of 25% 50 S plus-strands (anti-genomes). (Auth.)

  11. Characteristics of Filoviridae: Marburg and Ebola Viruses

    Science.gov (United States)

    Beer, Brigitte; Kurth, Reinhard; Bukreyev, Alexander

    Filoviruses are enveloped, nonsegmented negative-stranded RNA viruses. The two species, Marburg and Ebola virus, are serologically, biochemically, and genetically distinct. Marburg virus was first isolated during an outbreak in Europe in 1967, and Ebola virus emerged in 1976 as the causative agent of two simultaneous outbreaks in southern Sudan and northern Zaire. Although the main route of infection is known to be person-to-person transmission by intimate contact, the natural reservoir for filoviruses still remains a mystery.

  12. RNA binding and replication by the poliovirus RNA polymerase

    International Nuclear Information System (INIS)

    Oberste, M.S.

    1988-01-01

    RNA binding and RNA synthesis by the poliovirus RNA-dependent RNA polymerase were studied in vitro using purified polymerase. Templates for binding and RNA synthesis studies were natural RNAs, homopolymeric RNAs, or subgenomic poliovirus-specific RNAs synthesized in vitro from cDNA clones using SP6 or T7 RNA polymerases. The binding of the purified polymerase to poliovirion and other RNAs was studied using a protein-RNA nitrocellulose filter binding assay. A cellular poly(A)-binding protein was found in the viral polymerase preparations, but was easily separated from the polymerase by chromatography on poly(A) Sepharose. The binding of purified polymerase to 32 P-labeled ribohomopolymeric RNAs was examined, and the order of binding observed was poly(G) >>> poly(U) > poly(C) > poly(A). The K a for polymerase binding to poliovirion RNA and to a full-length negative strand transcript was about 1 x 10 9 M -1 . The polymerase binds to a subgenomic RNAs which contain the 3' end of the genome with a K a similar to that for virion RNA, but binds less well to 18S rRNA, globin mRNA, and subgenomic RNAs which lack portions of the 3' noncoding region

  13. Analysis of intermolecular RNA-RNA recombination by rubella virus

    International Nuclear Information System (INIS)

    Adams, Sandra D.; Tzeng, W.-P.; Chen, M.-H.; Frey, Teryl K.

    2003-01-01

    To investigate whether rubella virus (RUB) undergoes intermolecular RNA-RNA recombination, cells were cotransfected with pairs of in vitro transcripts from genomic cDNA plasmid vectors engineered to contain nonoverlapping deletions: the replicative transcript maintained the 5'-proximal nonstructural (NS) ORF (which contained the replicase, making it RNA replication competent), had a deletion in the 3'-proximal structural protein (SP) ORF, and maintained the 3' end of the genome, including the putative 3' cis-acting elements (CSE), while the nonreplicative transcript consisted of the 3' half of the genome including the SP-ORF and 3' CSE. Cotransfection yielded plaque-forming virus that synthesized the standard genomic and subgenomic RNAs and thus was generated by RNA-RNA recombination. Using transcripts tagged with a 3'-terminal deletion, it was found that recombinants contained the 3' end derived from the replicative strand, indicating a cis-preference for initiation of negative-strand synthesis. In cotransfections in which the replicative transcript lacked the 3' CSE, recombination occurred, albeit at lower efficiency, indicating that initiation in trans from the NS-ORF can occur. The 3' CSE was sufficient as a nonreplicative transcript, showing that it can serve as a promoter for negative-strand RNA synthesis. While deletion mutagenesis showed that the presence of the junction untranslated region (J-UTR) between the ORFs appeared to be necessary on both transcripts for recombination in this region of the genome, analysis with transcripts tagged with restriction sites showed that the J-UTR was not a hot spot for recombination compared to neighboring regions in both ORFs. Sequence analysis of recombinants revealed that both precise (homologous) and imprecise recombination (aberrant, homologous resulting in duplications) occurred; however, imprecise recombination only involved the J-UTR or the 3' end of the NS-ORF and the J-UTR (maintaining the NS-ORF), indicating

  14. Sequence analysis of L RNA of Lassa virus

    International Nuclear Information System (INIS)

    Vieth, Simon; Torda, Andrew E.; Asper, Marcel; Schmitz, Herbert; Guenther, Stephan

    2004-01-01

    The L RNA of three Lassa virus strains originating from Nigeria, Ghana/Ivory Coast, and Sierra Leone was sequenced and the data subjected to structure predictions and phylogenetic analyses. The L gene products had 2218-2221 residues, diverged by 18% at the amino acid level, and contained several conserved regions. Only one region of 504 residues (positions 1043-1546) could be assigned a function, namely that of an RNA polymerase. Secondary structure predictions suggest that this domain is very similar to RNA-dependent RNA polymerases of known structure encoded by plus-strand RNA viruses, permitting a model to be built. Outside the polymerase region, there is little structural data, except for regions of strong alpha-helical content and probably a coiled-coil domain at the N terminus. No evidence for reassortment or recombination during Lassa virus evolution was found. The secondary structure-assisted alignment of the RNA polymerase region permitted a reliable reconstruction of the phylogeny of all negative-strand RNA viruses, indicating that Arenaviridae are most closely related to Nairoviruses. In conclusion, the data provide a basis for structural and functional characterization of the Lassa virus L protein and reveal new insights into the phylogeny of negative-strand RNA viruses

  15. Prolonged detection of dengue virus RNA in the semen of a man returning from Thailand to Italy, January 2018.

    Science.gov (United States)

    Lalle, Eleonora; Colavita, Francesca; Iannetta, Marco; Gebremeskel Teklè, Saba; Carletti, Fabrizio; Scorzolini, Laura; Bordi, Licia; Vincenti, Donatella; Castilletti, Concetta; Ippolito, Giuseppe; Capobianchi, Maria Rosaria; Nicastri, Emanuele

    2018-05-01

    This study reports the presence of dengue virus RNA in longitudinally collected semen samples of a previously healthy Caucasian man, returning to Italy from Thailand with primary dengue fever, up to 37 days post-symptom onset, when viraemia and viruria were undetectable. This finding, coupled with the evidence of dengue virus negative-strand RNA, an indirect marker of ongoing viral replication, in the cellular fraction of semen, indicates a need to further investigate possible sexual transmission.

  16. A Polyamide Inhibits Replication of Vesicular Stomatitis Virus by Targeting RNA in the Nucleocapsid

    Energy Technology Data Exchange (ETDEWEB)

    Gumpper, Ryan H.; Li, Weike; Castañeda, Carlos H.; Scuderi, M. José; Bashkin, James K.; Luo, Ming; Dutch, Rebecca Ellis

    2018-02-07

    Polyamides have been shown to bind double-stranded DNA by complementing the curvature of the minor groove and forming various hydrogen bonds with DNA. Several polyamide molecules have been found to have potent antiviral activities against papillomavirus, a double-stranded DNA virus. By analogy, we reason that polyamides may also interact with the structured RNA bound in the nucleocapsid of a negative-strand RNA virus. Vesicular stomatitis virus (VSV) was selected as a prototype virus to test this possibility since its genomic RNA encapsidated in the nucleocapsid forms a structure resembling one strand of an A-form RNA duplex. One polyamide molecule, UMSL1011, was found to inhibit infection of VSV. To confirm that the polyamide targeted the nucleocapsid, a nucleocapsid-like particle (NLP) was incubated with UMSL1011. The encapsidated RNA in the polyamide-treated NLP was protected from thermo-release and digestion by RNase A. UMSL1011 also inhibits viral RNA synthesis in the intracellular activity assay for the viral RNA-dependent RNA polymerase. The crystal structure revealed that UMSL1011 binds the structured RNA in the nucleocapsid. The conclusion of our studies is that the RNA in the nucleocapsid is a viable antiviral target of polyamides. Since the RNA structure in the nucleocapsid is similar in all negative-strand RNA viruses, polyamides may be optimized to target the specific RNA genome of a negative-strand RNA virus, such as respiratory syncytial virus and Ebola virus.

    IMPORTANCENegative-strand RNA viruses (NSVs) include several life-threatening pathogens, such as rabies virus, respiratory syncytial virus, and Ebola virus. There are no effective antiviral drugs against these viruses. Polyamides offer an exceptional opportunity because they may be optimized to target each NSV. Our studies on vesicular stomatitis virus, an NSV, demonstrated that a polyamide molecule could specifically target the viral RNA in the nucleocapsid and inhibit

  17. Small catalytic RNA: Structure, function and application

    Energy Technology Data Exchange (ETDEWEB)

    Monforte, Joseph Albert [Univ. of California, Berkeley, CA (United States)

    1991-04-01

    We have utilized a combination of photochemical cross-linking techniques and site-directed mutagenesis to obtain secondary and tertiary structure information for the self-cleaving, self-ligating subsequence of RNA from the negative strand of Satellite Tobacco Ringspot Virus. We have found that the helical regions fold about a hinge to promoting four different possible tertiary interactions, creating a molecular of similar shape to a paperclip. A model suggesting that the ``paperclip`` and ``hammerhead`` RNAs share a similar three dimensional structure is proposed. We have used a self-cleaving RNA molecule related to a subsequence of plant viroids, a ``hammerhead,`` to study the length-dependent folding of RNA produced during transcription by RNA polymerase. We have used this method to determine the length of RNA sequestered within elongating E. coli and T7 RNA polymerase complexes. The data show that for E. coli RNA polymerase 121±s are sequestered within the ternary complex, which is consistent with the presence of an RNA-DNA hybrid within the transcription bubble, as proposed by others. The result for T7 RNA polymerase differs from E. coli RNA polymerase, with only 10{plus_minus}1 nucleotides sequestered within the ternary complex, setting a new upper limit for the minimum RNA-DNA required for a stable elongating complex. Comparisons between E. coli and T7 RNA polymerase are made. The relevance of the results to models or transcription termination, abortive initiation, and initiation to elongation mode transitions are discussed.

  18. Citrus psorosis virus RNA 1 is of negative polarity and potentially encodes in its complementary strand a 24K protein of unknown function and 280K putative RNA dependent RNA polymerase.

    Science.gov (United States)

    Naum-Onganía, Gabriela; Gago-Zachert, Selma; Peña, Eduardo; Grau, Oscar; Garcia, Maria Laura

    2003-10-01

    Citrus psorosis virus (CPsV), the type member of genus Ophiovirus, has three genomic RNAs. Complete sequencing of CPsV RNA 1 revealed a size of 8184 nucleotides and Northern blot hybridization with chain specific probes showed that its non-coding strand is preferentially encapsidated. The complementary strand of RNA 1 contains two open reading frames (ORFs) separated by a 109-nt intergenic region, one located near the 5'-end potentially encoding a 24K protein of unknown function, and another of 280K containing the core polymerase motifs characteristic of viral RNA-dependent RNA polymerases (RdRp). Comparison of the core RdRp motifs of negative-stranded RNA viruses, supports grouping CPsV, Ranunculus white mottle virus (RWMV) and Mirafiori lettuce virus (MiLV) within the same genus (Ophiovirus), constituting a monophyletic group separated from all other negative-stranded RNA viruses. Furthermore, RNAs 1 of MiLV, CPsV and RWMV are similar in size and those of MiLV and CPsV also in genomic organization and sequence.

  19. Dengue viral RNA levels in peripheral blood mononuclear cells are associated with disease severity and preexisting dengue immune status.

    Directory of Open Access Journals (Sweden)

    Anon Srikiatkhachorn

    Full Text Available Infection with dengue viruses (DENV causes a wide range of manifestations from asymptomatic infection to a febrile illness called dengue fever (DF, to dengue hemorrhagic fever (DHF. The in vivo targets of DENV and the relation between the viral burden in these cells and disease severity are not known.The levels of positive and negative strand viral RNA in peripheral blood monocytes, T/NK cells, and B cells and in plasma of DF and DHF cases were measured by quantitative RT-PCR.Positive strand viral RNA was detected in monocytes, T/NK cells and B cells with the highest amounts found in B cells. Viral RNA levels in CD14+ cells and plasma were significantly higher in DHF compared to DF, and in cases with a secondary infection compared to those undergoing a primary infection. The distribution of viral RNA among cell subpopulations was similar in DF and DHF cases. Small amounts of negative strand RNA were found in a few cases only. The severity of plasma leakage correlated with viral RNA levels in plasma and in CD14+ cells.B cells were the principal cells containing DENV RNA in peripheral blood, but overall there was little active DENV RNA replication detectable in peripheral blood mononuclear cells (PBMC. Secondary infection and DHF were associated with higher viral burden in PBMC populations, especially CD14+ monocytes, suggesting that viral infection of these cells may be involved in disease pathogenesis.

  20. Small catalytic RNA: Structure, function and application

    Energy Technology Data Exchange (ETDEWEB)

    Monforte, J.A.

    1991-04-01

    We have utilized a combination of photochemical cross-linking techniques and site-directed mutagenesis to obtain secondary and tertiary structure information for the self-cleaving, self-ligating subsequence of RNA from the negative strand of Satellite Tobacco Ringspot Virus. We have found that the helical regions fold about a hinge to promoting four different possible tertiary interactions, creating a molecular of similar shape to a paperclip. A model suggesting that the paperclip'' and hammerhead'' RNAs share a similar three dimensional structure is proposed. We have used a self-cleaving RNA molecule related to a subsequence of plant viroids, a hammerhead,'' to study the length-dependent folding of RNA produced during transcription by RNA polymerase. We have used this method to determine the length of RNA sequestered within elongating E. coli and T7 RNA polymerase complexes. The data show that for E. coli RNA polymerase 12{plus minus}1 nucleotides are sequestered within the ternary complex, which is consistent with the presence of an RNA-DNA hybrid within the transcription bubble, as proposed by others. The result for T7 RNA polymerase differs from E. coli RNA polymerase, with only 10{plus minus}1 nucleotides sequestered within the ternary complex, setting a new upper limit for the minimum RNA-DNA required for a stable elongating complex. Comparisons between E. coli and T7 RNA polymerase are made. The relevance of the results to models or transcription termination, abortive initiation, and initiation to elongation mode transitions are discussed.

  1. Ocular Manifestations of Ebola Virus Disease: An Ophthalmologist's Guide to Prevent Infection and Panic

    Science.gov (United States)

    Vingolo, Enzo Maria; Messano, Giuseppe Alessio; Fragiotta, Serena; Petti, Stefano

    2015-01-01

    Ebola virus disease (EVD—formerly known as Ebola hemorrhagic fever) is a severe hemorrhagic fever caused by lipid-enveloped, nonsegmented, negative-stranded RNA viruses belonging to the genus Ebolavirus. Case fatality rates may reach up to 76% of infected individuals, making this infection a deadly health problem in the sub-Saharan population. At the moment, there are still no indications on ophthalmological clinical signs and security suggestions for healthcare professionals (doctors and nurses or cooperative persons). This paper provides a short but complete guide to reduce infection risks. PMID:26557674

  2. Marburg Virus Reverse Genetics Systems

    Directory of Open Access Journals (Sweden)

    Kristina Maria Schmidt

    2016-06-01

    Full Text Available The highly pathogenic Marburg virus (MARV is a member of the Filoviridae family and belongs to the group of nonsegmented negative-strand RNA viruses. Reverse genetics systems established for MARV have been used to study various aspects of the viral replication cycle, analyze host responses, image viral infection, and screen for antivirals. This article provides an overview of the currently established MARV reverse genetic systems based on minigenomes, infectious virus-like particles and full-length clones, and the research that has been conducted using these systems.

  3. Nucleocapsid-like structures of Ebola virus reconstructed using electron tomography

    International Nuclear Information System (INIS)

    Noda, T.; Aoyama, K.; Sagara, H.; Kida, H.; Kawaoka, Y.

    2005-01-01

    Electron tomography (ET) is a new technique for high resolution, three-dimensional (3D) reconstruction of pleiomocphic mac. n)molecular complexes, such as virus components. By employing this technique, we resolved the 3D structure of Ebola virus nucleocapsid-like (NC-like) structures in the cytoplasm of cells expressing NP, VP24, and VP35: the minimum components required to form these NC-like structures. Reconstruction of these tubular NC-like structures of Ebola virus showed them to be composed of left-handed helices spaced at short intervals, which is structurally consistent with other non-segmented negative-strand RNA viruses

  4. RNA synthesis is modulated by G-quadruplex formation in Hepatitis C virus negative RNA strand.

    Science.gov (United States)

    Chloé, Jaubert; Amina, Bedrat; Laura, Bartolucci; Carmelo, Di Primo; Michel, Ventura; Jean-Louis, Mergny; Samir, Amrane; Marie-Line, Andreola

    2018-05-25

    DNA and RNA guanine-rich oligonucleotides can form non-canonical structures called G-quadruplexes or "G4" that are based on the stacking of G-quartets. The role of DNA and RNA G4 is documented in eukaryotic cells and in pathogens such as viruses. Yet, G4 have been identified only in a few RNA viruses, including the Flaviviridae family. In this study, we analysed the last 157 nucleotides at the 3'end of the HCV (-) strand. This sequence is known to be the minimal sequence required for an efficient RNA replication. Using bioinformatics and biophysics, we identified a highly conserved G4-prone sequence located in the stem-loop IIy' of the negative strand. We also showed that the formation of this G-quadruplex inhibits the in vitro RNA synthesis by the RdRp. Furthermore, Phen-DC3, a specific G-quadruplex binder, is able to inhibit HCV viral replication in cells in conditions where no cytotoxicity was measured. Considering that this domain of the negative RNA strand is well conserved among HCV genotypes, G4 ligands could be of interest for new antiviral therapies.

  5. Nucleocytoplasmic transport of nucleocapsid proteins of enveloped RNA viruses

    Directory of Open Access Journals (Sweden)

    Wahyu eWulan

    2015-06-01

    Full Text Available Most viruses with non-segmented single stranded RNA genomes complete their life cycle in the cytoplasm of infected cells. However, despite undergoing replication in the cytoplasm, the structural proteins of some of these RNA viruses localize to the nucleus at specific times in the virus life cycle, primarily early in infection. Limited evidence suggests that this enhances successful viral replication by interfering with or inhibiting the host antiviral response. Nucleocapsid proteins of RNA viruses have a well-established, essential cytoplasmic role in virus replication and assembly. Intriguingly, nucleocapsid proteins of some RNA viruses also localize to the nucleus/nucleolus of infected cells. Their nuclear function is less well understood although significant advances have been made in recent years. This review will focus on the nucleocapsid protein of cytoplasmic enveloped RNA viruses, including their localization to the nucleus/nucleolus and function therein. A greater understanding of the nuclear localization of nucleocapsid proteins has the potential to enhance therapeutic strategies as it can be a target for the development of live-attenuated vaccines or antiviral drugs.

  6. Ins and Outs of Multipartite Positive-Strand RNA Plant Viruses: Packaging versus Systemic Spread

    Directory of Open Access Journals (Sweden)

    Mattia Dall’Ara

    2016-08-01

    Full Text Available Viruses possessing a non-segmented genome require a specific recognition of their nucleic acid to ensure its protection in a capsid. A similar feature exists for viruses having a segmented genome, usually consisting of viral genomic segments joined together into one viral entity. While this appears as a rule for animal viruses, the majority of segmented plant viruses package their genomic segments individually. To ensure a productive infection, all viral particles and thereby all segments have to be present in the same cell. Progression of the virus within the plant requires as well a concerted genome preservation to avoid loss of function. In this review, we will discuss the “life aspects” of chosen phytoviruses and argue for the existence of RNA-RNA interactions that drive the preservation of viral genome integrity while the virus progresses in the plant.

  7. [Investigation of RNA viral genome amplification by multiple displacement amplification technique].

    Science.gov (United States)

    Pang, Zheng; Li, Jian-Dong; Li, Chuan; Liang, Mi-Fang; Li, De-Xin

    2013-06-01

    In order to facilitate the detection of newly emerging or rare viral infectious diseases, a negative-strand RNA virus-severe fever with thrombocytopenia syndrome bunyavirus, and a positive-strand RNA virus-dengue virus, were used to investigate RNA viral genome unspecific amplification by multiple displacement amplification technique from clinical samples. Series of 10-fold diluted purified viral RNA were utilized as analog samples with different pathogen loads, after a series of reactions were sequentially processed, single-strand cDNA, double-strand cDNA, double-strand cDNA treated with ligation without or with supplemental RNA were generated, then a Phi29 DNA polymerase depended isothermal amplification was employed, and finally the target gene copies were detected by real time PCR assays to evaluate the amplification efficiencies of various methods. The results showed that multiple displacement amplification effects of single-strand or double-strand cDNA templates were limited, while the fold increases of double-strand cDNA templates treated with ligation could be up to 6 X 10(3), even 2 X 10(5) when supplemental RNA existed, and better results were obtained when viral RNA loads were lower. A RNA viral genome amplification system using multiple displacement amplification technique was established in this study and effective amplification of RNA viral genome with low load was achieved, which could provide a tool to synthesize adequate viral genome for multiplex pathogens detection.

  8. A novel monopartite dsRNA virus isolated from the entomopathogenic and nematophagous fungus Purpureocillium lilacinum.

    Science.gov (United States)

    Herrero, Noemi

    2016-12-01

    Purpureocillium lilacinum is a ubiquitous saprophytic fungus commonly isolated from soils and widely known as a biological control agent against phytopathogenic nematodes and pest insects. Mycoviruses infect a wide number of fungal species, but the study of viruses infecting entomopathogenic fungi is still quite recent. In this study, a total of 86 P. lilacinum isolates collected from soil in natural and cultivated habitats throughout the Czech Republic were analyzed; 22 % of the isolates harbored double-stranded RNA (dsRNA) elements with viral characteristics. These results suggest that mycoviruses are common in P. lilacinum. One of the most common dsRNA elements detected in the survey was completely sequenced and corresponded to the 2,864-bp genome of a previously undescribed mycovirus, designated Purpureocillium lilacinum nonsegmented virus 1 (PlNV-1). Phylogenetic analysis of the RNA-dependent RNA polymerase of PlNV-1 indicated that this virus might belong to a new taxon related to the family Partitiviridae.

  9. Dynamics of picornavirus RNA replication within infected cells

    DEFF Research Database (Denmark)

    Belsham, Graham; Normann, Preben

    2008-01-01

    Replication of many picornaviruses is inhibited by low concentrations of guanidine. Guanidine-resistant mutants are readily isolated and the mutations map to the coding region for the 2C protein. Using in vitro replication assays it has been determined previously that guanidine blocks the initiat......Replication of many picornaviruses is inhibited by low concentrations of guanidine. Guanidine-resistant mutants are readily isolated and the mutations map to the coding region for the 2C protein. Using in vitro replication assays it has been determined previously that guanidine blocks...... the initiation of negative-strand synthesis. We have now examined the dynamics of RNA replication, measured by quantitative RT-PCR, within cells infected with either swine vesicular disease virus (an enterovirus) or foot-and-mouth disease virus as regulated by the presence or absence of guanidine. Following...... the removal of guanidine from the infected cells, RNA replication occurs after a significant lag phase. This restoration of RNA synthesis requires de novo protein synthesis. Viral RNA can be maintained for at least 72 h within cells in the absence of apparent replication but guanidine-resistant virus can...

  10. Structural dissection of human metapneumovirus phosphoprotein using small angle x-ray scattering.

    Science.gov (United States)

    Renner, Max; Paesen, Guido C; Grison, Claire M; Granier, Sébastien; Grimes, Jonathan M; Leyrat, Cédric

    2017-11-01

    The phosphoprotein (P) is the main and essential cofactor of the RNA polymerase (L) of non-segmented, negative-strand RNA viruses. P positions the viral polymerase onto its nucleoprotein-RNA template and acts as a chaperone of the nucleoprotein (N), thereby preventing nonspecific encapsidation of cellular RNAs. The phosphoprotein of human metapneumovirus (HMPV) forms homotetramers composed of a stable oligomerization domain (P core ) flanked by large intrinsically disordered regions (IDRs). Here we combined x-ray crystallography of P core with small angle x-ray scattering (SAXS)-based ensemble modeling of the full-length P protein and several of its fragments to provide a structural description of P that captures its dynamic character, and highlights the presence of varyingly stable structural elements within the IDRs. We discuss the implications of the structural properties of HMPV P for the assembly and functioning of the viral transcription/replication machinery.

  11. The 3'-terminal 55 nucleotides of bovine coronavirus defective interfering RNA harbor cis-acting elements required for both negative- and positive-strand RNA synthesis.

    Directory of Open Access Journals (Sweden)

    Wei-Yu Liao

    Full Text Available The synthesis of the negative-strand [(--strand] complement of the ∼30 kilobase, positive-strand [(+-strand] coronaviral genome is a necessary early step for genome replication. The identification of cis-acting elements required for (--strand RNA synthesis in coronaviruses, however, has been hampered due to insufficiencies in the techniques used to detect the (--strand RNA species. Here, we employed a method of head-to-tail ligation and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR to detect and quantitate the synthesis of bovine coronavirus (BCoV defective interfering (DI RNA (- strands. Furthermore, using the aforementioned techniques along with Northern blot assay, we specifically defined the cis-acting RNA elements within the 3'-terminal 55 nucleotides (nts which function in the synthesis of (-- or (+-strand BCoV DI RNA. The major findings are as follows: (i nts from -5 to -39 within the 3'-terminal 55 nts are the cis-acting elements responsible for (--strand BCoV DI RNA synthesis, (ii nts from -3 to -34 within the 3'-terminal 55 nts are cis-acting elements required for (+-strand BCoV DI RNA synthesis, and (iii the nucleotide species at the 3'-most position (-1 is important, but not critical, for both (-- and (+-strand BCoV DI RNA synthesis. These results demonstrate that the 3'-terminal 55 nts in BCoV DI RNA harbor cis-acting RNA elements required for both (-- and (+-strand DI RNA synthesis and extend our knowledge on the mechanisms of coronavirus replication. The method of head-to-tail ligation and qRT-PCR employed in the study may also be applied to identify other cis-acting elements required for (--strand RNA synthesis in coronaviruses.

  12. The Ebola Virus VP30-NP Interaction Is a Regulator of Viral RNA Synthesis.

    Directory of Open Access Journals (Sweden)

    Robert N Kirchdoerfer

    2016-10-01

    Full Text Available Filoviruses are capable of causing deadly hemorrhagic fevers. All nonsegmented negative-sense RNA-virus nucleocapsids are composed of a nucleoprotein (NP, a phosphoprotein (VP35 and a polymerase (L. However, the VP30 RNA-synthesis co-factor is unique to the filoviruses. The assembly, structure, and function of the filovirus RNA replication complex remain unclear. Here, we have characterized the interactions of Ebola, Sudan and Marburg virus VP30 with NP using in vitro biochemistry, structural biology and cell-based mini-replicon assays. We have found that the VP30 C-terminal domain interacts with a short peptide in the C-terminal region of NP. Further, we have solved crystal structures of the VP30-NP complex for both Ebola and Marburg viruses. These structures reveal that a conserved, proline-rich NP peptide binds a shallow hydrophobic cleft on the VP30 C-terminal domain. Structure-guided Ebola virus VP30 mutants have altered affinities for the NP peptide. Correlation of these VP30-NP affinities with the activity for each of these mutants in a cell-based mini-replicon assay suggests that the VP30-NP interaction plays both essential and inhibitory roles in Ebola virus RNA synthesis.

  13. The Ebola Virus VP30-NP Interaction Is a Regulator of Viral RNA Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kirchdoerfer, Robert N.; Moyer, Crystal L.; Abelson, Dafna M.; Saphire, Erica Ollmann (Scripps)

    2016-10-18

    Filoviruses are capable of causing deadly hemorrhagic fevers. All nonsegmented negative-sense RNA-virus nucleocapsids are composed of a nucleoprotein (NP), a phosphoprotein (VP35) and a polymerase (L). However, the VP30 RNA-synthesis co-factor is unique to the filoviruses. The assembly, structure, and function of the filovirus RNA replication complex remain unclear. Here, we have characterized the interactions of Ebola, Sudan and Marburg virus VP30 with NP using in vitro biochemistry, structural biology and cell-based mini-replicon assays. We have found that the VP30 C-terminal domain interacts with a short peptide in the C-terminal region of NP. Further, we have solved crystal structures of the VP30-NP complex for both Ebola and Marburg viruses. These structures reveal that a conserved, proline-rich NP peptide binds a shallow hydrophobic cleft on the VP30 C-terminal domain. Structure-guided Ebola virus VP30 mutants have altered affinities for the NP peptide. Correlation of these VP30-NP affinities with the activity for each of these mutants in a cell-based mini-replicon assay suggests that the VP30-NP interaction plays both essential and inhibitory roles in Ebola virus RNA synthesis.

  14. The structure of the nucleoprotein binding domain of lyssavirus phosphoprotein reveals a structural relationship between the N-RNA binding domains of Rhabdoviridae and Paramyxoviridae.

    Science.gov (United States)

    Delmas, Olivier; Assenberg, Rene; Grimes, Jonathan M; Bourhy, Hervé

    2010-01-01

    The phosphoprotein P of non-segmented negative-sense RNA viruses is an essential component of the replication and transcription complex and acts as a co-factor for the viral RNA-dependent RNA polymerase. P recruits the viral polymerase to the nucleoprotein-bound viral RNA (N-RNA) via an interaction between its C-terminal domain and the N-RNA complex. We have obtained the structure of the C-terminal domain of P of Mokola virus (MOKV), a lyssavirus that belongs to the Rhabdoviridae family and mapped at the amino acid level the crucial positions involved in interaction with N and in the formation of the viral replication complex. Comparison of the N-RNA binding domains of P solved to date suggests that the N-RNA binding domains are structurally conserved among paramyxoviruses and rhabdoviruses in spite of low sequence conservation. We also review the numerous other functions of this domain and more generally of the phosphoprotein.

  15. RNA Crystallization

    Science.gov (United States)

    Golden, Barbara L.; Kundrot, Craig E.

    2003-01-01

    RNA molecules may be crystallized using variations of the methods developed for protein crystallography. As the technology has become available to syntheisize and purify RNA molecules in the quantities and with the quality that is required for crystallography, the field of RNA structure has exploded. The first consideration when crystallizing an RNA is the sequence, which may be varied in a rational way to enhance crystallizability or prevent formation of alternate structures. Once a sequence has been designed, the RNA may be synthesized chemically by solid-state synthesis, or it may be produced enzymatically using RNA polymerase and an appropriate DNA template. Purification of milligram quantities of RNA can be accomplished by HPLC or gel electrophoresis. As with proteins, crystallization of RNA is usually accomplished by vapor diffusion techniques. There are several considerations that are either unique to RNA crystallization or more important for RNA crystallization. Techniques for design, synthesis, purification, and crystallization of RNAs will be reviewed here.

  16. RNA Origami

    DEFF Research Database (Denmark)

    Sparvath, Steffen Lynge

    introducerede vores gruppe den enkeltstrengede RNA-origami metode, der giver mulighed for cotranscriptional foldning af veldefinerede nanostrukturer, og er en central del af arbejdet præsenteret heri. Denne ph.d.-afhandling udforsker potentielle anvendelser af RNA-origami nanostrukturer, som nanomedicin eller...... biosensorer. Afhandlingen består af en introduktion til RNA-nanoteknologi feltet, en introduktion af enkeltstrenget RNA-origami design, og fire studier, der beskriver design, produktion og karakterisering af både strukturelle og funktionelle RNA-origamier. Flere RNA-origami designs er blevet undersøgt, og...... projekterne, der indgår i denne afhandling, inkluderer de nyeste fremskridt indenfor strukturel RNA-nanoteknologi og udvikling af funktionelle RNA-baserede enheder. Det første studie beskriver konstruktion og karakterisering af en enkeltstrenget 6-helix RNA-origami stuktur, som er den første demonstration af...

  17. Respiratory syncytial virus mechanisms to interfere with type 1 interferons.

    Science.gov (United States)

    Barik, Sailen

    2013-01-01

    Respiratory syncytial virus (RSV) is a member of the Paramyxoviridae family that consists of viruses with nonsegmented negative-strand RNA genome. Infection by these viruses triggers the innate antiviral response of the host, mainly type I interferon (IFN). Essentially all other viruses of this family produce IFN suppressor functions by co-transcriptional RNA editing. In contrast, RSV has evolved two unique nonstructural proteins, NS1 and NS2, to effectively serve this purpose. Together, NS1 and NS2 degrade or sequester multiple signaling proteins that affect both IFN induction and IFN effector functions. While the mechanism of action of NS1 and NS2 is a subject of active research, their effect on adaptive immunity is also being recognized. In this review, we discuss various aspects of NS1 and NS2 function with implications for vaccine design.

  18. Quantitative analysis of dengue-2 virus RNA during the extrinsic incubation period in individual Aedes aegypti.

    Science.gov (United States)

    Richardson, Jason; Molina-Cruz, Alvaro; Salazar, Ma Isabel; Black, William

    2006-01-01

    Dengue virus-2 (DENV-2) RNA was quantified from the midgut and legs of individual Aedes aegypti at each of 14 days postinfectious blood meal (dpi) in a DENV-2 susceptible strain from Chetumal, Mexico. A SYBR Green I based strand-specific, quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) assay was developed. The lower detection and quantitation limits were 20 and 200 copies per reaction, respectively. Amounts of positive and negative strand viral RNA strands were correlated. Numbers of plaque-forming units (PFU) were correlated with DENV-2 RNA copy number in both C6/36 cell cultures and mosquitoes. PFU were consistently lower than RNA copy number by 2-3 log(10). Midgut levels of DENV-2 RNA peaked 8 dpi and fluctuated erratically between 6 and 9 dpi. Copies of DENV-2 RNA varied significantly among infected mosquitoes at each time point. Quantitative real-time RT-PCR is a convenient and reliable method that provides new insights into virus-vector interactions.

  19. Dual functions of Rift Valley fever virus NSs protein: inhibition of host mRNA transcription and post-transcriptional downregulation of protein kinase PKR.

    Science.gov (United States)

    Ikegami, Tetsuro; Narayanan, Krishna; Won, Sungyong; Kamitani, Wataru; Peters, C J; Makino, Shinji

    2009-09-01

    Rift Valley fever virus (RVFV), which belongs to the genus Phlebovirus, family Bunyaviridae, is a negative-stranded RNA virus carrying a single-stranded, tripartite RNA genome. RVFV is an important zoonotic pathogen transmitted by mosquitoes and causes large outbreaks among ruminants and humans in Africa and the Arabian Peninsula. Human patients develop an acute febrile illness, followed by a fatal hemorrhagic fever, encephalitis, or ocular diseases. A viral nonstructural protein, NSs, is a major viral virulence factor. Past studies showed that NSs suppresses the transcription of host mRNAs, including interferon-beta mRNAs. Here we demonstrated that the NSs protein induced post-transcriptional downregulation of dsRNA-dependent protein kinase (PKR), to prevent phosphorylation of eIF2alpha and promoted viral translation in infected cells. These two biological activities of the NSs most probably have a synergistic effect in suppressing host innate immune functions and facilitate efficient viral replication in infected mammalian hosts.

  20. Rift valley fever virus nonstructural protein NSs promotes viral RNA replication and transcription in a minigenome system.

    Science.gov (United States)

    Ikegami, Tetsuro; Peters, C J; Makino, Shinji

    2005-05-01

    Rift Valley fever virus (RVFV), which belongs to the genus Phlebovirus, family Bunyaviridae, has a tripartite negative-strand genome (S, M, and L segments) and is an important mosquito-borne pathogen for domestic animals and humans. We established an RVFV T7 RNA polymerase-driven minigenome system in which T7 RNA polymerase from an expression plasmid drove expression of RNA transcripts for viral proteins and minigenome RNA transcripts carrying a reporter gene between both termini of the M RNA segment in 293T cells. Like other viruses of the Bunyaviridae family, replication and transcription of the RVFV minigenome required expression of viral N and L proteins. Unexpectedly, the coexpression of an RVFV nonstructural protein, NSs, with N and L proteins resulted in a significant enhancement of minigenome RNA replication. Coexpression of NSs protein with N and L proteins also enhanced minigenome mRNA transcription in the cells expressing viral-sense minigenome RNA transcripts. NSs protein expression increased the RNA replication of minigenomes that originated from S and L RNA segments. Enhancement of minigenome RNA synthesis by NSs protein occurred in cells lacking alpha/beta interferon (IFN-alpha/beta) genes, indicating that the effect of NSs protein on minigenome RNA replication was unrelated to a putative NSs protein-induced inhibition of IFN-alpha/beta production. Our finding that RVFV NSs protein augmented minigenome RNA synthesis was in sharp contrast to reports that Bunyamwera virus (genus Bunyavirus) NSs protein inhibits viral minigenome RNA synthesis, suggesting that RVFV NSs protein and Bunyamwera virus NSs protein have distinctly different biological roles in viral RNA synthesis.

  1. Comparison of various methods of detection of different forms of dengue virus type 2 RNA in cultured cells

    International Nuclear Information System (INIS)

    Liu, H.S.; Lin, Y.L.; Chen, C.C.

    1997-01-01

    In this report, the sensitivity of various methods of detection of dengue virus type 2 (DEN-2) sense, antisense, replicative intermediate (RI) and replicative form (RF) RNAs in infected mosquito Aedes pseudoscutellaris AP-61 and mammalian baby hamster kidney BHK-21 cells is compared. LiCl precipitation was used for separation of viral RF RNA from RI RNA. Our results show that reverse transcription-polymerase chain reaction (RT-PCR) followed by Southern blot analysis and slot blot hybridisation of LiCl-fractionated RNA were the most sensitive methods of detection of viral RNA and determination of its single-stranded form. Northern blot analysis was the least sensitive method of detection of any form of viral RNA. U sing slot blot hybridisation of LiCl-precipitated RNA, viral RI RNA containing de novo synthesised negative strand viral RNA was first detected 30 min after virus inoculation in both cell lines. This is the earliest time of detection of DEN viral RNA synthesis in host cells so far reported. However, RF RNA could not be detected until 24 hrs post infection (p.i.) in AP-61 and 2 days p.i. in BHK-21 cells, respectively. The sequential order of individual forms of viral RNA detected in the infected cells was RI, RF and genomic RNAs. Viral RNA was detected in AP-61 cells always earlier than in BHK-21 cells. Moreover, the level of viral RNA in AP-61 cells was higher than that in BHK-21 cells, suggesting that the virus replicated more actively in AP-61 cells. In conclusion, the LiCl separation of viral RNA followed by slot blot hybridisation was found to be the most sensitive and reliable method of detection of DEN virus RI, RF and genomic RNAs in the infected cells. Moreover, this method can be applied to determine the replication status of any single-stranded RNA virus in the host. (authors)

  2. Persistence of ZIKV-RNA in the cellular fraction of semen is accompanied by a surrogate-marker of viral replication. Diagnostic implications for sexual transmission.

    Science.gov (United States)

    Biava, Mirella; Caglioti, Claudia; Castilletti, Concetta; Bordi, Licia; Carletti, Fabrizio; Colavita, Francesca; Quartu, Serena; Nicastri, Emanuele; Iannetta, Marco; Vairo, Francesco; Liuzzi, Giuseppina; Taglietti, Fabrizio; Ippolito, Giuseppe; Capobianchi, Maria Rosaria; Lalle, Eleonora

    2018-01-01

    As asymptomatic infections represent 80% of ZIKV-infected individuals, sexual transmission is a rising concern. Recent studies highlighted a preferential association of ZIKV with the cellular fraction (CF) of different specimen types. Our aim was to evaluate the presence of ZIKV-RNA in different body fluids, focusing on semen specimens to assess the ZIKV-RNA content in either the unfractionated sample, its CF or seminal plasma (SP). In addition, to establish if the presence of ZIKV genome was associated with active virus replication, we measured the levels of negative-strand ZIKV-RNA. ZIKV total-RNA was detected in blood, urine and unfractionated semen, and neg-RNA in semen CF and SP samples longitudinally collected from two ZIKV-positive men followed at the National Institute for Infectious Diseases "L. Spallanzani", Italy. In both patients, ZIKV total-RNA was detected in CF with ct values always lower than in the corresponding unfractionated samples, and was observed even in the CF from negative unfractionated semen samples. In Patient 2, neg-RNA was also detected in CF, suggesting ongoing viral replication. Our results demonstrate higher clinical sensitivity of CF as compared to whole semen testing, emphasizing the need to extend ZIKV-RNA testing to CF, to rule out virus presence and the possible risk of sexual transmission.

  3. Structural and mutational analyses of cis-acting sequences in the 5'-untranslated region of satellite RNA of bamboo mosaic potexvirus

    International Nuclear Information System (INIS)

    Annamalai, Padmanaban; Hsu, Y.-H.; Liu, Y.-P.; Tsai, C.-H.; Lin, N.-S.

    2003-01-01

    The satellite RNA of Bamboo mosaic virus (satBaMV) contains on open reading frame for a 20-kDa protein that is flanked by a 5'-untranslated region (UTR) of 159 nucleotides (nt) and a 3'-UTR of 129 nt. A secondary structure was predicted for the 5'-UTR of satBaMV RNA, which folds into a large stem-loop (LSL) and a small stem-loop. Enzymatic probing confirmed the existence of LSL (nt 8-138) in the 5'-UTR. The essential cis-acting sequences in the 5'-UTR required for satBaMV RNA replication were determined by deletion and substitution mutagenesis. Their replication efficiencies were analyzed in Nicotiana benthamiana protoplasts and Chenopodium quinoa plants coinoculated with helper BaMV RNA. All deletion mutants abolished the replication of satBaMV RNA, whereas mutations introduced in most of the loop regions and stems showed either no replication or a decreased replication efficiency. Mutations that affected the positive-strand satBaMV RNA accumulation also affected the accumulation of negative-strand RNA; however, the accumulation of genomic and subgenomic RNAs of BaMV were not affected. Moreover, covariation analyses of natural satBaMV variants provide substantial evidence that the secondary structure in the 5'-UTR of satBaMV is necessary for efficient replication

  4. Influenza polymerase encoding mRNAs utilize atypical mRNA nuclear export.

    Science.gov (United States)

    Larsen, Sean; Bui, Steven; Perez, Veronica; Mohammad, Adeba; Medina-Ramirez, Hilario; Newcomb, Laura L

    2014-08-28

    Influenza is a segmented negative strand RNA virus. Each RNA segment is encapsulated by influenza nucleoprotein and bound by the viral RNA dependent RNA polymerase (RdRP) to form viral ribonucleoproteins responsible for RNA synthesis in the nucleus of the host cell. Influenza transcription results in spliced mRNAs (M2 and NS2), intron-containing mRNAs (M1 and NS1), and intron-less mRNAs (HA, NA, NP, PB1, PB2, and PA), all of which undergo nuclear export into the cytoplasm for translation. Most cellular mRNA nuclear export is Nxf1-mediated, while select mRNAs utilize Crm1. Here we inhibited Nxf1 and Crm1 nuclear export prior to infection with influenza A/Udorn/307/1972(H3N2) virus and analyzed influenza intron-less mRNAs using cellular fractionation and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). We examined direct interaction between Nxf1 and influenza intron-less mRNAs using immuno purification of Nxf1 and RT-PCR of associated RNA. Inhibition of Nxf1 resulted in less influenza intron-less mRNA export into the cytoplasm for HA and NA influenza mRNAs in both human embryonic kidney cell line (293 T) and human lung adenocarcinoma epithelial cell line (A549). However, in 293 T cells no change was observed for mRNAs encoding the components of the viral ribonucleoproteins; NP, PA, PB1, and PB2, while in A549 cells, only PA, PB1, and PB2 mRNAs, encoding the RdRP, remained unaffected; NP mRNA was reduced in the cytoplasm. In A549 cells NP, NA, HA, mRNAs were found associated with Nxf1 but PA, PB1, and PB2 mRNAs were not. Crm1 inhibition also resulted in no significant difference in PA, PB1, and PB2 mRNA nuclear export. These results further confirm Nxf1-mediated nuclear export is functional during the influenza life cycle and hijacked for select influenza mRNA nuclear export. We reveal a cell type difference for Nxf1-mediated nuclear export of influenza NP mRNA, a reminder that cell type can influence molecular mechanisms. Importantly, we

  5. RNA oxidation

    DEFF Research Database (Denmark)

    Kjaer, L. K.; Cejvanovic, V.; Henriken, T.

    2015-01-01

    .9 significant hazard ratio for death compared with the quartile with the lowest 8oxoGuo excretion when adjusted for age, sex, BMI, smoker status, s-HbA1c, urine protein excretion and s-cholesterol. We conclude that it is now established that RNA oxidation is an independent risk factor for death in type 2...

  6. An RNA Virome Associated to the Golden Orb-Weaver Spider Nephila clavipes

    Directory of Open Access Journals (Sweden)

    Humberto J. Debat

    2017-10-01

    Full Text Available The golden orb-weaver spider Nephila clavipes, known for its sexual size dimorphism, is abundant and widespread in the New World. The first annotated genome of orb-weaver spiders, exploring N. clavipes, has recently been reported. The study, focused primarily on the diversity of silk specific genes, shed light into the complex evolutionary history of spiders. Furthermore, a robust transcriptome analysis provided a massive resource for N. clavipes RNA survey. Here, I present evidence of viral sequences corresponding to the first 10 extant virus species associated to N. clavipes and indeed, nephilids. The putatively new species are linked to ssRNA positive-strand viruses, such as Picornavirales, and to ssRNA negative-strand and dsRNA viruses. In addition, I detected sequence data of new strains of two recently reported arthropod viruses, which complemented and extended the corresponding sequence references. The identified viruses appear to be complete, potentially functional, and presenting the typical architecture and consistent viral domains. The intrinsic nature of the detected sequences and their absence in the recently generated genome assembly, suggest that they correspond to bona fide RNA virus sequences. The available RNA data allowed for the first time to address a tissue/organ specific analysis of virus loads/presence in spiders, suggesting a complex spatial and differential distribution of the tentative viruses, encompassing the spider brain and also silk and venom glands. Until recently, the virus landscape associated to spiders remained elusive. The discovered viruses described here provide only a fragmented glimpse of the potential magnitude of the Aranea virosphere. Future studies should focus not only on complementing and expanding these findings, but also on addressing the potential ecological role of these viruses, which might influence the biology of these outstanding arthropod species.

  7. Funções de afilamento não segmentadas e segmentadas para Tectona grandis na região centro-sul matogrossense Non-segmented and segmented taper models to Tectona grandis in center-southern region of Mato Grosso

    Directory of Open Access Journals (Sweden)

    Sidney Fernando Caldeira

    2012-12-01

    Full Text Available O objetivo deste estudo foi comparar a acurácia dos modelos polinomiais não segmentados do quinto grau e de Hradetzky de 1976 e os segmentados de Max e Burkhart de1976 e Clark et al. de 1991, na estimativa dos diâmetros ao longo do fuste de Tectona grandis L.f., com ajustes para o conjunto total dos dados e por classe de diâmetro, em um povoamento com 16 anos, na região centro- sul matogrossense. A base de dados foi composta por 114 árvores, cubadas pela metodologia de Hohenadl modificada e distribuídas em classes de diâmetro. O ajuste dos modelos foi avaliado em função do coeficiente de determinação corrigido, erro padrão da estimativa e pela distribuição dos resíduos em porcentagem. A acuracidade dos modelos ao longo do fuste foi avaliada pelo desvio, desvio padrão das diferenças, somatório de quadrado dos resíduos relativos e a porcentagem dos resíduos. A Equação de Hradetzky foi a que apresentou o melhor ajuste para estimar os diâmetros ao longo do fuste de Tectona grandis tanto para o conjunto total dos dados quanto para as classes de diâmetro com os menores valores nas estatísticas auxiliares, exceto na Classe 3, onde a equação selecionada foi a de Clark et al. The aim of this study was to compare the accuracy of the non-segmented polynomial models of Fifth degree and Hradetzky from 1976 and the segmented models of Max and Burkhart from 1976 and Clark et al. from 1991, in estimating diameters along the stem of Tectona grandis L.f., with adjustments for the full set of data and by diameter class in a 16 years old stand in the center–southern region of Mato Grosso State, Brazil. The database consisted of 114 trees, scaled by the modified Hohenadl method and distributed in diameter classes. The models adjustments were evaluated according to the adjusted coefficient of determination, standard eError of estimate and distribution of residuals. The accuracy of the models along the stem was evaluated by deviation

  8. Extracellular RNA Communication (ExRNA)

    Data.gov (United States)

    Federal Laboratory Consortium — Until recently, scientists believed RNA worked mostly inside the cell that produced it. Some types of RNA help translate genes into proteins that are necessary for...

  9. Replication of honey bee-associated RNA viruses across multiple bee species in apple orchards of Georgia, Germany and Kyrgyzstan.

    Science.gov (United States)

    Radzevičiūtė, Rita; Theodorou, Panagiotis; Husemann, Martin; Japoshvili, George; Kirkitadze, Giorgi; Zhusupbaeva, Aigul; Paxton, Robert J

    2017-06-01

    The essential ecosystem service of pollination is provided largely by insects, which are considered threatened by diverse biotic and abiotic global change pressures. RNA viruses are one such pressure, and have risen in prominence as a major threat for honey bees (Apis mellifera) and global apiculture, as well as a risk factor for other bee species through pathogen spill-over between managed honey bees and sympatric wild pollinator communities. Yet despite their potential role in global bee decline, the prevalence of honey bee-associated RNA viruses in wild bees is poorly known from both geographic and taxonomic perspectives. We screened members of pollinator communities (honey bees, bumble bees and other wild bees belonging to four families) collected from apple orchards in Georgia, Germany and Kyrgyzstan for six common honey bee-associated RNA virus complexes encompassing nine virus targets. The Deformed wing virus complex (DWV genotypes A and B) had the highest prevalence across all localities and host species and was the only virus complex found in wild bee species belonging to all four studied families. Based on amplification of negative-strand viral RNA, we found evidence for viral replication in wild bee species of DWV-A/DWV-B (hosts: Andrena haemorrhoa and several Bombus spp.) and Black queen cell virus (hosts: Anthophora plumipes, several Bombus spp., Osmia bicornis and Xylocopa spp.). Viral amplicon sequences revealed that DWV-A and DWV-B are regionally distinct but identical in two or more bee species at any one site, suggesting virus is shared amongst sympatric bee taxa. This study demonstrates that honey bee associated RNA viruses are geographically and taxonomically widespread, likely infective in wild bee species, and shared across bee taxa. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Interferon antagonist NSs of La Crosse virus triggers a DNA damage response-like degradation of transcribing RNA polymerase II.

    Science.gov (United States)

    Verbruggen, Paul; Ruf, Marius; Blakqori, Gjon; Överby, Anna K; Heidemann, Martin; Eick, Dirk; Weber, Friedemann

    2011-02-04

    La Crosse encephalitis virus (LACV) is a mosquito-borne member of the negative-strand RNA virus family Bunyaviridae. We have previously shown that the virulence factor NSs of LACV is an efficient inhibitor of the antiviral type I interferon system. A recombinant virus unable to express NSs (rLACVdelNSs) strongly induced interferon transcription, whereas the corresponding wt virus (rLACV) suppressed it. Here, we show that interferon induction by rLACVdelNSs mainly occurs through the signaling pathway leading from the pattern recognition receptor RIG-I to the transcription factor IRF-3. NSs expressed by rLACV, however, acts downstream of IRF-3 by specifically blocking RNA polymerase II-dependent transcription. Further investigations revealed that NSs induces proteasomal degradation of the mammalian RNA polymerase II subunit RPB1. NSs thereby selectively targets RPB1 molecules of elongating RNA polymerase II complexes, the so-called IIo form. This phenotype has similarities to the cellular DNA damage response, and NSs was indeed found to transactivate the DNA damage response gene pak6. Moreover, NSs expressed by rLACV boosted serine 139 phosphorylation of histone H2A.X, one of the earliest cellular reactions to damaged DNA. However, other DNA damage response markers such as up-regulation and serine 15 phosphorylation of p53 or serine 1524 phosphorylation of BRCA1 were not triggered by LACV infection. Collectively, our data indicate that the strong suppression of interferon induction by LACV NSs is based on a shutdown of RNA polymerase II transcription and that NSs achieves this by exploiting parts of the cellular DNA damage response pathway to degrade IIo-borne RPB1 subunits.

  11. Porcine Reproductive and Respiratory Syndrome Virus Nucleocapsid Protein Interacts with Nsp9 and Cellular DHX9 To Regulate Viral RNA Synthesis.

    Science.gov (United States)

    Liu, Long; Tian, Jiao; Nan, Hao; Tian, Mengmeng; Li, Yuan; Xu, Xiaodong; Huang, Baicheng; Zhou, Enmin; Hiscox, Julian A; Chen, Hongying

    2016-06-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) nucleocapsid (N) protein is the main component of the viral capsid to encapsulate viral RNA, and it is also a multifunctional protein involved in the regulation of host cell processes. Nonstructural protein 9 (Nsp9) is the RNA-dependent RNA polymerase that plays a critical role in viral RNA transcription and replication. In this study, we demonstrate that PRRSV N protein is bound to Nsp9 by protein-protein interaction and that the contacting surface on Nsp9 is located in the two predicted α-helixes formed by 48 residues at the C-terminal end of the protein. Mutagenesis analyses identified E646, E608, and E611 on Nsp9 and Q85 on the N protein as the pivotal residues participating in the N-Nsp9 interaction. By overexpressing the N protein binding fragment of Nsp9 in infected Marc-145 cells, the synthesis of viral RNAs, as well as the production of infectious progeny viruses, was dramatically inhibited, suggesting that Nsp9-N protein association is involved in the process of viral RNA production. In addition, we show that PRRSV N interacts with cellular RNA helicase DHX9 and redistributes the protein into the cytoplasm. Knockdown of DHX9 increased the ratio of short subgenomic mRNAs (sgmRNAs); in contrast, DHX9 overexpression benefited the synthesis of longer sgmRNAs and the viral genomic RNA (gRNA). These results imply that DHX9 is recruited by the N protein in PRRSV infection to regulate viral RNA synthesis. We postulate that N and DHX9 may act as antiattenuation factors for the continuous elongation of nascent transcript during negative-strand RNA synthesis. It is unclear whether the N protein of PRRSV is involved in regulation of the viral RNA production process. In this report, we demonstrate that the N protein of the arterivirus PRRSV participates in viral RNA replication and transcription through interacting with Nsp9 and its RdRp and recruiting cellular RNA helicase to promote the production of

  12. Combinatorics of RNA-RNA interaction

    DEFF Research Database (Denmark)

    Li, Thomas J X; Reidys, Christian

    2012-01-01

    RNA-RNA binding is an important phenomenon observed for many classes of non-coding RNAs and plays a crucial role in a number of regulatory processes. Recently several MFE folding algorithms for predicting the joint structure of two interacting RNA molecules have been proposed. Here joint structure...... means that in a diagram representation the intramolecular bonds of each partner are pseudoknot-free, that the intermolecular binding pairs are noncrossing, and that there is no so-called "zigzag" configuration. This paper presents the combinatorics of RNA interaction structures including...

  13. High antiviral effect of TiO2·PL–DNA nanocomposites targeted to conservative regions of (−RNA and (+RNA of influenza A virus in cell culture

    Directory of Open Access Journals (Sweden)

    Asya S. Levina

    2016-08-01

    Full Text Available Background: The development of new antiviral drugs based on nucleic acids is under scrutiny. An important problem in this aspect is to find the most vulnerable conservative regions in the viral genome as targets for the action of these agents. Another challenge is the development of an efficient system for their delivery into cells. To solve this problem, we proposed a TiO2·PL–DNA nanocomposite consisting of titanium dioxide nanoparticles and polylysine (PL-containing oligonucleotides.Results: The TiO2·PL–DNA nanocomposites bearing the DNA fragments targeted to different conservative regions of (−RNA and (+RNA of segment 5 of influenza A virus (IAV were studied for their antiviral activity in MDCK cells infected with the H1N1, H5N1, and H3N2 virus subtypes. Within the negative strand of each of the studied strains, the efficiency of DNA fragments increased in the direction of its 3’-end. Thus, the DNA fragment aimed at the 3’-noncoding region of (−RNA was the most efficient and inhibited the reproduction of different IAV subtypes by 3–4 orders of magnitude. Although to a lesser extent, the DNA fragments targeted at the AUG region of (+RNA and the corresponding region of (−RNA were also active. For all studied viral subtypes, the nanocomposites bearing the DNA fragments targeted to (−RNA appeared to be more efficient than those containing fragments aimed at the corresponding (+RNA regions.Conclusion: The proposed TiO2·PL–DNA nanocomposites can be successfully used for highly efficient and site-specific inhibition of influenza A virus of different subtypes. Some patterns of localization of the most vulnerable regions in IAV segment 5 for the action of DNA-based drugs were found. The (−RNA strand of IAV segment 5 appeared to be more sensitive as compared to (+RNA.

  14. RNA modifications by oxidation

    DEFF Research Database (Denmark)

    Poulsen, Henrik E; Specht, Elisabeth; Broedbaek, Kasper

    2012-01-01

    to encompass various classes of novel regulatory RNAs, including, e.g., microRNAs. It is well known that DNA is constantly oxidized and repaired by complex genome maintenance mechanisms. Analogously, RNA also undergoes significant oxidation, and there are now convincing data suggesting that oxidation......The past decade has provided exciting insights into a novel class of central (small) RNA molecules intimately involved in gene regulation. Only a small percentage of our DNA is translated into proteins by mRNA, yet 80% or more of the DNA is transcribed into RNA, and this RNA has been found......, and the consequent loss of integrity of RNA, is a mechanism for disease development. Oxidized RNA is found in a large variety of diseases, and interest has been especially devoted to degenerative brain diseases such as Alzheimer disease, in which up to 50-70% of specific mRNA molecules are reported oxidized, whereas...

  15. Working with RNA

    DEFF Research Database (Denmark)

    Nielsen, Henrik

    2011-01-01

    Working with RNA is not a special discipline in molecular biology. However, RNA is chemically and structurally different from DNA and a few simple work rules have to be implemented to maintain the integrity of the RNA. Alkaline pH, high temperatures, and heavy metal ions should be avoided when po...

  16. Reverse genetics of measles virus and resulting multivalent recombinant vaccines: applications of recombinant measles viruses.

    Science.gov (United States)

    Billeter, M A; Naim, H Y; Udem, S A

    2009-01-01

    An overview is given on the development of technologies to allow reverse genetics of RNA viruses, i.e., the rescue of viruses from cDNA, with emphasis on nonsegmented negative-strand RNA viruses (Mononegavirales), as exemplified for measles virus (MV). Primarily, these technologies allowed site-directed mutagenesis, enabling important insights into a variety of aspects of the biology of these viruses. Concomitantly, foreign coding sequences were inserted to (a) allow localization of virus replication in vivo through marker gene expression, (b) develop candidate multivalent vaccines against measles and other pathogens, and (c) create candidate oncolytic viruses. The vector use of these viruses was experimentally encouraged by the pronounced genetic stability of the recombinants unexpected for RNA viruses, and by the high load of insertable genetic material, in excess of 6 kb. The known assets, such as the small genome size of the vector in comparison to DNA viruses proposed as vectors, the extensive clinical experience of attenuated MV as vaccine with a proven record of high safety and efficacy, and the low production cost per vaccination dose are thus favorably complemented.

  17. Whole genome sequence analysis of the arctic-lineage strain responsible for distemper in Italian wolves and dogs through a fast and robust next generation sequencing protocol.

    Science.gov (United States)

    Marcacci, Maurilia; Ancora, Massimo; Mangone, Iolanda; Teodori, Liana; Di Sabatino, Daria; De Massis, Fabrizio; Camma', Cesare; Savini, Giovanni; Lorusso, Alessio

    2014-06-01

    Dynamic surveillance and characterization of canine distemper virus (CDV) circulating strains are essential against possible vaccine breakthroughs events. This study describes the setup of a fast and robust next-generation sequencing (NGS) Ion PGM™ protocol that was used to obtain the complete genome sequence of a CDV isolate (CDV2784/2013). CDV2784/2013 is the prototype of CDV strains responsible for severe clinical distemper in dogs and wolves in Italy during 2013. CDV2784/2013 was isolated on cell culture and total RNA was used for NGS sample preparation. A total of 112.3 Mb of reads were assembled de novo using MIRA version 4.0rc4, which yielded a total number of 403 contigs with 12.1% coverage. The whole genome (15,690 bp) was recovered successfully and compared to those of existing CDV whole genomes. CDV2784/2013 was shown to have 92% nt identity with the Onderstepoort vaccine strain. This study describes for the first time a fast and robust Ion PGM™ platform-based whole genome amplification protocol for non-segmented negative stranded RNA viruses starting from total cell-purified RNA. Additionally, this is the first study reporting the whole genome analysis of an Arctic lineage strain that is known to circulate widely in Europe, Asia and USA. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. The complete genome structure and phylogenetic relationship of infectious hematopoietic necrosis virus

    Science.gov (United States)

    Morzunov , Sergey P.; Winton, James R.; Nichol, Stuart T.

    1995-01-01

    Infectious hematopoietic necrosis virus (IHNV), a member of the family Rhabdoviridae, causes a severe disease with high mortality in salmonid fish. The nucleotide sequence (11, 131 bases) of the entire genome was determined for the pathogenic WRAC strain of IHNV from southern Idaho. This allowed detailed analysis of all 6 genes, the deduced amino acid sequences of their encoded proteins, and important control motifs including leader, trailer and gene junction regions. Sequence analysis revealed that the 6 virus genes are located along the genome in the 3′ to 5′ order: nucleocapsid (N), polymerase-associated phosphoprotein (P or M1), matrix protein (M or M2), surface glycoprotein (G), a unique non-virion protein (NV) and virus polymerase (L). The IHNV genome RNA was found to have highly complementary termini (15 of 16 nucleotides). The gene junction regions display the highly conserved sequence UCURUC(U)7RCCGUG(N)4CACR (in the vRNA sense), which includes the typical rhabdovirus transcription termination/polyadenylation signal and a novel putative transcription initiation signal. Phylogenetic analysis of M, G and L protein sequences allowed insights into the evolutionary and taxonomic relationship of rhabdoviruses of fish relative to those of insects or mammals, and a broader sense of the relationship of non-segmented negative-strand RNA viruses. Based on these data, a new genus, piscivirus, is proposed which will initially contain IHNV, viral hemorrhagic septicemia virus and Hirame rhabdovirus.

  19. Methods for RNA Analysis

    DEFF Research Database (Denmark)

    Olivarius, Signe

    of the transcriptome, 5’ end capture of RNA is combined with next-generation sequencing for high-throughput quantitative assessment of transcription start sites by two different methods. The methods presented here allow for functional investigation of coding as well as noncoding RNA and contribute to future...... RNAs rely on interactions with proteins, the establishment of protein-binding profiles is essential for the characterization of RNAs. Aiming to facilitate RNA analysis, this thesis introduces proteomics- as well as transcriptomics-based methods for the functional characterization of RNA. First, RNA...

  20. Cytoplasmic Z-RNA

    International Nuclear Information System (INIS)

    Zarling, D.A.; Calhoun, C.J.; Hardin, C.C.; Zarling, A.H.

    1987-01-01

    Specific immunochemical probes for Z-RNA were generated and characterized to search for possible Z-RNA-like double helices in cells. Z-RNA was detected in the cytoplasm of fixed protozoan cells by immunofluorescence microscopy using these anti-Z-RNA IgCs. In contrast, autoimmune or experimentally elicited anti-DNA antibodies, specifically reactive with B-DNA or Z-DNA, stained the nuclei. Pre-or nonimmune IgGs did not bind to the cells. RNase A or T1 digestion eliminated anti-Z-RNA IgG binding to cytoplasmic determinants; however, DNase I or mung bean nuclease had no effect. Doxorubicin and ethidium bromide prevented anti-Z-RNA antibody binding; however, actinomycin D, which does not bind double-stranded RNA, did not. Anti-Z-RNA immunofluorescence was specifically blocked in competition assays by synthetic Z-RNA but not Z-DNA, A-RNA, or single-stranded RNAs. Thus, some cytoplasmic sequences in fixed cells exist in the left-handed Z-RNA conformation

  1. Transmission of HCV to a chimpanzee using virus particles produced in an RNA-transfected HepG2 cell culture.

    Science.gov (United States)

    Dash, S; Kalkeri, G; McClure, H M; Garry, R F; Clejan, S; Thung, S N; Murthy, K K

    2001-10-01

    It was demonstrated previously that HepG2 cells produce negative strand RNA and virus-like particles after transfection with RNA transcribed from a full-length hepatitis C virus (HCV) cDNA clone [Dash et al. (1997) American Journal of Pathology, 151:363-373]. To determine in vivo infectivity of these in vitro synthesized viral particles, a chimpanzee was inoculated intravenously with HCV derived from HepG2 cells. The infected chimpanzee was examined serially for elevation of liver enzymes, for the presence of HCV RNA in the serum by reverse transcription nested polymerase chain reaction (RT-PCR), anti-HCV antibodies in the serum, and inflammation in the liver. The chimpanzee developed elevated levels of liver enzymes after the second week, but the levels fluctuated over a 10-week period. HCV RNA was detected in the serum of the chimpanzee at the second, seventh and ninth weeks after inoculation, and remained positive up to 25 weeks. Liver biopsies at Weeks 18 and 19 revealed of mild inflammation. Nucleotide sequence analysis of HCV recovered from the infected chimpanzee at the second and ninth weeks showed 100% sequence homology with the clone used for transfection studies. Serum anti-HCV antibodies were not detected by EIA during the 25 weeks follow-up period. These results suggest that intravenous administration of the virus-like particles derived from RNA-transfected HepG2 cells are infectious, and therefore, the pMO9.6-T7 clone is an infectious clone. These results provide new information that in vitro synthesized HCV particles produced from full-length HCV clone can cause infection in a chimpanzee. This study will facilitate the use of innovative approaches to the study of assembly of HCV particles and mechanisms of virus infectivity in cell culture. Copyright 2001 Wiley-Liss, Inc.

  2. RNA decay by messenger RNA interferases

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Mikkel; Overgaard, Martin; Winther, Kristoffer Skovbo

    2008-01-01

    Two abundant toxin-antitoxin (TA) gene families, relBE and mazEF, encode mRNA cleaving enzymes whose ectopic overexpression abruptly inhibits translation and thereby induces a bacteriostatic condition. Here we describe and discuss protocols for the overproduction, purification, and analysis of mR...... cleaving enzymes such as RelE of Escherichia coli and the corresponding antitoxin RelB. In particular, we describe a set of plasmid vectors useful for the detailed analysis of cleavage sites in model mRNAs.......Two abundant toxin-antitoxin (TA) gene families, relBE and mazEF, encode mRNA cleaving enzymes whose ectopic overexpression abruptly inhibits translation and thereby induces a bacteriostatic condition. Here we describe and discuss protocols for the overproduction, purification, and analysis of mRNA...

  3. Assembly of Ebola virus matrix protein VP40 is regulated by latch-like properties of N and C terminal tails.

    Directory of Open Access Journals (Sweden)

    Leslie P Silva

    Full Text Available The matrix protein VP40 coordinates numerous functions in the viral life cycle of the Ebola virus. These range from the regulation of viral transcription to morphogenesis, packaging and budding of mature virions. Similar to the matrix proteins of other nonsegmented, negative-strand RNA viruses, VP40 proceeds through intermediate states of assembly (e.g. octamers but it remains unclear how these intermediates are coordinated with the various stages of the life cycle. In this study, we investigate the molecular basis of synchronization as governed by VP40. Hydrogen/deuterium exchange mass spectrometry was used to follow induced structural and conformational changes in VP40. Together with computational modeling, we demonstrate that both extreme N and C terminal tail regions stabilize the monomeric state through a direct association. The tails appear to function as a latch, released upon a specific molecular trigger such as RNA ligation. We propose that triggered release of the tails permits the coordination of late-stage events in the viral life cycle, at the inner membrane of the host cell. Specifically, N-tail release exposes the L-domain motifs PTAP/PPEY to the transport and budding complexes, whereas triggered C-tail release could improve association with the site of budding.

  4. Topology of RNA-RNA interaction structures

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Huang, Fenix Wenda; Penner, Robert

    2012-01-01

    Abstract The topological filtration of interacting RNA complexes is studied, and the role is analyzed of certain diagrams called irreducible shadows, which form suitable building blocks for more general structures. We prove that, for two interacting RNAs, called interaction structures, there exist...

  5. RNA Localization in Astrocytes

    DEFF Research Database (Denmark)

    Thomsen, Rune

    2012-01-01

    , regulation of the blood brain barrier and glial scar tissue formation. Despite the involvement in various CNS functions only a limited number of studies have addressed mRNA localization in astrocytes. This PhD project was initially focused on developing and implementing methods that could be used to asses mRNA......Messenger RNA (mRNA) localization is a mechanism by which polarized cells can regulate protein synthesis to specific subcellular compartments in a spatial and temporal manner, and plays a pivotal role in multiple physiological processes from embryonic development to cell differentiation...... localization in astrocyte protrusions, and following look into the subcellular localization pattern of specific mRNA species of both primary astrocytes isolated from cortical hemispheres of newborn mice, and the mouse astrocyte cell line, C8S. The Boyden chamber cell fractionation assay was optimized, in a way...

  6. An Amino Acid of Human Parainfluenza Virus Type 3 Nucleoprotein Is Critical for Template Function and Cytoplasmic Inclusion Body Formation

    Science.gov (United States)

    Zhang, Shengwei; Chen, Longyun; Zhang, Guangyuan; Yan, Qin; Yang, Xiaodan; Ding, Binbin; Tang, Qiaopeng; Sun, Shengjun; Hu, Zhulong

    2013-01-01

    The nucleoprotein (N) and phosphoprotein (P) interaction of nonsegmented negative-strand RNA viruses is essential for viral replication; this includes N0-P (N0, free of RNA) interaction and the interaction of N-RNA with P. The precise site(s) within N that mediates the N-P interaction and the detailed regulating mechanism, however, are less clear. Using a human parainfluenza virus type 3 (HPIV3) minigenome assay, we found that an N mutant (NL478A) did not support reporter gene expression. Using in vivo and in vitro coimmunoprecipitation, we found that NL478A maintains the ability to form NL478A0-P, to self-assemble, and to form NL478A-RNA but that NL478A-RNA does not interact with P. Using an immunofluorescence assay, we found that N-P interaction provides the minimal requirement for the formation of cytoplasmic inclusion bodies, which contain viral RNA, N, P, and polymerase in HPIV3-infected cells. NL478A was unable to form inclusion bodies when coexpressed with P, but the presence of N rescued the ability of NL478A to form inclusion bodies and the transcriptional function of NL478A, thereby suggesting that hetero-oligomers formed by N and NL478A are functional and competent to form inclusion bodies. Furthermore, we found that NL478A is also defective in virus growth. To our knowledge, we are the first to use a paramyxovirus to identify a precise amino acid within N that is critical for N-RNA and P interaction but not for N0-P interaction for the formation of inclusion bodies, which appear to be bona fide sites of RNA synthesis. PMID:24027324

  7. Assembling RNA Nanoparticles.

    Science.gov (United States)

    Xiao, Shou-Jun

    2017-01-01

    RNA nanoparticles are designed and self-assembled according to noncanonical interactions of naturally conserved RNA motifs and/or canonical Watson-Crick base-pairing interactions, which have potential applications in gene therapy and nanomedicine. These artificially engineered nanoparticles are mainly synthesized from in vitro transcribed RNAs, purified by denaturing and native polyacrylamide gel electrophoresis (PAGE), and characterized with native PAGE, AFM, and TEM technologies. The protocols of in vitro transcription, denaturing and native PAGE, and RNA nanoparticle self-assembly are described in detail.

  8. Plant RNA binding proteins for control of RNA virus infection

    Directory of Open Access Journals (Sweden)

    Sung Un eHuh

    2013-12-01

    Full Text Available Plant RNA viruses have effective strategies to infect host plants through either direct or indirect interactions with various host proteins, thus suppressing the host immune system. When plant RNA viruses enter host cells exposed RNAs of viruses are recognized by the host immune system through processes such as siRNA-dependent silencing. Interestingly, some host RNA binding proteins have been involved in the inhibition of RNA virus replication, movement, and translation through RNA-specific binding. Host plants intensively use RNA binding proteins for defense against viral infections in nature. In this mini review, we will summarize the function of some host RNA binding proteins which act in a sequence-specific binding manner to the infecting virus RNA. It is important to understand how plants effectively suppresses RNA virus infections via RNA binding proteins, and this defense system can be potentially developed as a synthetic virus defense strategy for use in crop engineering.

  9. Shapes of interacting RNA complexes

    DEFF Research Database (Denmark)

    Fu, Benjamin Mingming; Reidys, Christian

    2014-01-01

    Shapes of interacting RNA complexes are studied using a filtration via their topological genus. A shape of an RNA complex is obtained by (iteratively) collapsing stacks and eliminating hairpin loops.This shape-projection preserves the topological core of the RNA complex and for fixed topological...... genus there are only finitely many such shapes. Our main result is a new bijection that relates the shapes of RNA complexes with shapes of RNA structures. This allows to compute the shape polynomial of RNA complexes via the shape polynomial of RNA structures. We furthermore present a linear time uniform...... sampling algorithm for shapes of RNA complexes of fixed topological genus....

  10. Remote Network Access (RNA)

    National Research Council Canada - National Science Library

    2002-01-01

    .... Remote Network Access (RNA) includes or is associated with all communication devices/software, firewalls, intrusion detection systems and virus protection applications to ensure security of the OIG, DoD, Network from remote...

  11. RNA/PNA Approach

    Indian Academy of Sciences (India)

    In this approach we want to develop structural analogue of the leader that might have higher affinity towards the Phosphoprotein, but would impair the dimerization process and viral leader RNA binding.

  12. Switching off small RNA regulation with trap-mRNA

    DEFF Research Database (Denmark)

    Overgaard, Martin; Johansen, Jesper; Møller-Jensen, Jakob

    2009-01-01

    to operate at the level of transcription initiation. By employing a highly sensitive genetic screen we uncovered a novel RNA-based regulatory principle in which induction of a trap-mRNA leads to selective degradation of a small regulatory RNA molecule, thereby abolishing the sRNA-based silencing of its...

  13. Characterization of a viral phosphoprotein binding site on the surface of the respiratory syncytial nucleoprotein.

    Science.gov (United States)

    Galloux, Marie; Tarus, Bogdan; Blazevic, Ilfad; Fix, Jenna; Duquerroy, Stéphane; Eléouët, Jean-François

    2012-08-01

    The human respiratory syncytial virus (HRSV) genome is composed of a negative-sense single-stranded RNA that is tightly associated with the nucleoprotein (N). This ribonucleoprotein (RNP) complex is the template for replication and transcription by the viral RNA-dependent RNA polymerase. RNP recognition by the viral polymerase involves a specific interaction between the C-terminal domain of the phosphoprotein (P) (P(CTD)) and N. However, the P binding region on N remains to be identified. In this study, glutathione S-transferase (GST) pulldown assays were used to identify the N-terminal core domain of HRSV N (N(NTD)) as a P binding domain. A biochemical characterization of the P(CTD) and molecular modeling of the N(NTD) allowed us to define four potential candidate pockets on N (pocket I [PI] to PIV) as hydrophobic sites surrounded by positively charged regions, which could constitute sites complementary to the P(CTD) interaction domain. The role of selected amino acids in the recognition of the N-RNA complex by P was first screened for by site-directed mutagenesis using a polymerase activity assay, based on an HRSV minigenome containing a luciferase reporter gene. When changed to Ala, most of the residues of PI were found to be critical for viral RNA synthesis, with the R132A mutant having the strongest effect. These mutations also reduced or abolished in vitro and in vivo P-N interactions, as determined by GST pulldown and immunoprecipitation experiments. The pocket formed by these residues is critical for P binding to the N-RNA complex, is specific for pneumovirus N proteins, and is clearly distinct from the P binding sites identified so far for other nonsegmented negative-strand viruses.

  14. A ribosome without RNA

    Directory of Open Access Journals (Sweden)

    Harold S Bernhardt

    2015-11-01

    Full Text Available It was Francis Crick who first asked why the ribosome contains so much RNA, and discussed the implications of this for the direct flow of genetic information from DNA to protein. Remarkable advances in our understanding of the ribosome and protein synthesis, including the recent publication of two mammalian mitochondrial ribosome structures, have shed new light on this intriguing aspect of evolution in molecular biology. We examine here whether RNA is indispensable for coded protein synthesis, or whether an all-protein ‘ribosome’ (or ‘synthosome’ might be possible, with a protein enzyme catalyzing peptide synthesis, and release factor-like protein adaptors able to read a message composed of deoxyribonucleotides. We also compare the RNA world hypothesis with the alternative ‘proteins first’ hypothesis in terms of their different understandings of the evolution of the ribosome, and whether this might have been preceded by an ancestral form of nonribosomal peptide synthesis catalyzed by protein enzymes.

  15. Pyrite footprinting of RNA

    International Nuclear Information System (INIS)

    Schlatterer, Jörg C.; Wieder, Matthew S.; Jones, Christopher D.; Pollack, Lois; Brenowitz, Michael

    2012-01-01

    Highlights: ► RNA structure is mapped by pyrite mediated · OH footprinting. ► Repetitive experiments can be done in a powdered pyrite filled cartridge. ► High · OH reactivity of nucleotides imply dynamic role in Diels–Alderase catalysis. -- Abstract: In RNA, function follows form. Mapping the surface of RNA molecules with chemical and enzymatic probes has revealed invaluable information about structure and folding. Hydroxyl radicals ( · OH) map the surface of nucleic acids by cutting the backbone where it is accessible to solvent. Recent studies showed that a microfluidic chip containing pyrite (FeS 2 ) can produce sufficient · OH to footprint DNA. The 49-nt Diels–Alder RNA enzyme catalyzes the C–C bond formation between a diene and a dienophile. A crystal structure, molecular dynamics simulation and atomic mutagenesis studies suggest that nucleotides of an asymmetric bulge participate in the dynamic architecture of the ribozyme’s active center. Of note is that residue U42 directly interacts with the product in the crystallized RNA/product complex. Here, we use powdered pyrite held in a commercially available cartridge to footprint the Diels–Alderase ribozyme with single nucleotide resolution. Residues C39 to U42 are more reactive to · OH than predicted by the solvent accessibility calculated from the crystal structure suggesting that this loop is dynamic in solution. The loop’s flexibility may contribute to substrate recruitment and product release. Our implementation of pyrite-mediated · OH footprinting is a readily accessible approach to gleaning information about the architecture of small RNA molecules.

  16. RNA Regulation of Estrogen

    Science.gov (United States)

    2010-08-01

    Berglund, Rodger Voelker, Paul Barber and Julien Diegel 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING...estrogen  receptors  [reviewed  in  (3,  4)],  also   functions   by  interacting  directly  with  RNA  to  alter  RNA...Mog myelin oligodendrocyte glycoprotein 6.06 207115_x_at mbtd1 mbt domain containing 1 6.06 208004_at Prol1 proline rich, lacrimal 1 6.06 205247_at

  17. RNA Regulation by Estrogen

    Science.gov (United States)

    2011-08-01

    Julien Diegel, Amy Mahady, and Micah Bodner 5e. TASK NUMBER E-Mail: aberglund@molbio.uoregon.edu 5f. WORK UNIT NUMBER 7. PERFORMING...4)],  also   functions   by  interacting  directly  with  RNA  to  alter  RNA  processing  events  such  as  splicing...1 6.06 208004_at Prol1 proline rich, lacrimal 1 6.06 205247_at NOTCH4 Notch homolog 4 (Drosophila) 6.06 211203_s_at Cntn1 contactin 1 6.06 220689_at

  18. Sensing of RNA viruses

    DEFF Research Database (Denmark)

    Jensen, Søren; Thomsen, Allan Randrup

    2012-01-01

    pathogen-associated molecular patterns have emerged in great detail. This review presents an overview of our current knowledge regarding the receptors used to detect RNA virus invasion, the molecular structures these receptors sense, and the involved downstream signaling pathways.......Our knowledge regarding the contribution of the innate immune system in recognizing and subsequently initiating a host response to an invasion of RNA virus has been rapidly growing over the last decade. Descriptions of the receptors involved and the molecular mechanisms they employ to sense viral...

  19. RNA STRAND: The RNA Secondary Structure and Statistical Analysis Database

    Directory of Open Access Journals (Sweden)

    Andronescu Mirela

    2008-08-01

    Full Text Available Abstract Background The ability to access, search and analyse secondary structures of a large set of known RNA molecules is very important for deriving improved RNA energy models, for evaluating computational predictions of RNA secondary structures and for a better understanding of RNA folding. Currently there is no database that can easily provide these capabilities for almost all RNA molecules with known secondary structures. Results In this paper we describe RNA STRAND – the RNA secondary STRucture and statistical ANalysis Database, a curated database containing known secondary structures of any type and organism. Our new database provides a wide collection of known RNA secondary structures drawn from public databases, searchable and downloadable in a common format. Comprehensive statistical information on the secondary structures in our database is provided using the RNA Secondary Structure Analyser, a new tool we have developed to analyse RNA secondary structures. The information thus obtained is valuable for understanding to which extent and with which probability certain structural motifs can appear. We outline several ways in which the data provided in RNA STRAND can facilitate research on RNA structure, including the improvement of RNA energy models and evaluation of secondary structure prediction programs. In order to keep up-to-date with new RNA secondary structure experiments, we offer the necessary tools to add solved RNA secondary structures to our database and invite researchers to contribute to RNA STRAND. Conclusion RNA STRAND is a carefully assembled database of trusted RNA secondary structures, with easy on-line tools for searching, analyzing and downloading user selected entries, and is publicly available at http://www.rnasoft.ca/strand.

  20. Studying RNA-protein interactions in vivo by RNA immunoprecipitation

    DEFF Research Database (Denmark)

    Selth, Luke A; Close, Pierre; Svejstrup, Jesper Q

    2011-01-01

    and have significant effects on gene expression. RNA immunoprecipitation (RIP) is a powerful technique used to detect direct and indirect interactions between individual proteins and specific RNA molecules in vivo. Here, we describe RIP methods for both yeast and mammalian cells.......The crucial roles played by RNA-binding proteins in all aspects of RNA metabolism, particularly in the regulation of transcription, have become increasingly evident. Moreover, other factors that do not directly interact with RNA molecules can nevertheless function proximally to RNA polymerases...

  1. Branched RNA: A New Architecture for RNA Interference

    Directory of Open Access Journals (Sweden)

    Anna Aviñó

    2011-01-01

    Full Text Available Branched RNAs with two and four strands were synthesized. These structures were used to obtain branched siRNA. The branched siRNA duplexes had similar inhibitory capacity as those of unmodified siRNA duplexes, as deduced from gene silencing experiments of the TNF-α protein. Branched RNAs are considered novel structures for siRNA technology, and they provide an innovative tool for specific gene inhibition. As the method described here is compatible with most RNA modifications described to date, these compounds may be further functionalized to obtain more potent siRNA derivatives and can be attached to suitable delivery systems.

  2. The RNA gene information: retroelement-microRNA entangling as the RNA quantum code.

    Science.gov (United States)

    Fujii, Yoichi Robertus

    2013-01-01

    MicroRNA (miRNA) and retroelements may be a master of regulator in our life, which are evolutionally involved in the origin of species. To support the Darwinism from the aspect of molecular evolution process, it has tremendously been interested in the molecular information of naive RNA. The RNA wave model 2000 consists of four concepts that have altered from original idea of the miRNA genes for crosstalk among embryonic stem cells, their niche cells, and retroelements as a carrier vesicle of the RNA genes. (1) the miRNA gene as a mobile genetic element induces transcriptional and posttranscriptional silencing via networking-processes (no hierarchical architecture); (2) the RNA information supplied by the miRNA genes expands to intracellular, intercellular, intraorgan, interorgan, intraspecies, and interspecies under the cycle of life into the global environment; (3) the mobile miRNAs can self-proliferate; and (4) cells contain two types information as resident and genomic miRNAs. Based on RNA wave, we have developed an interest in investigation of the transformation from RNA information to quantum bits as physicochemical characters of RNA with the measurement of RNA electron spin. When it would have been given that the fundamental bases for the acquired characters in genetics can be controlled by RNA gene information, it may be available to apply for challenging against RNA gene diseases, such as stress-induced diseases.

  3. Plant RNA Regulatory Network and RNA Granules in Virus Infection

    Directory of Open Access Journals (Sweden)

    Kristiina Mäkinen

    2017-12-01

    Full Text Available Regulation of post-transcriptional gene expression on mRNA level in eukaryotic cells includes translocation, translation, translational repression, storage, mRNA decay, RNA silencing, and nonsense-mediated decay. These processes are associated with various RNA-binding proteins and cytoplasmic ribonucleoprotein complexes many of which are conserved across eukaryotes. Microscopically visible aggregations formed by ribonucleoprotein complexes are termed RNA granules. Stress granules where the translationally inactive mRNAs are stored and processing bodies where mRNA decay may occur present the most studied RNA granule types. Diverse RNP-granules are increasingly being assigned important roles in viral infections. Although the majority of the molecular level studies on the role of RNA granules in viral translation and replication have been conducted in mammalian systems, some studies link also plant virus infection to RNA granules. An increasing body of evidence indicates that plant viruses require components of stress granules and processing bodies for their replication and translation, but how extensively the cellular mRNA regulatory network is utilized by plant viruses has remained largely enigmatic. Antiviral RNA silencing, which is an important regulator of viral RNA stability and expression in plants, is commonly counteracted by viral suppressors of RNA silencing. Some of the RNA silencing suppressors localize to cellular RNA granules and have been proposed to carry out their suppression functions there. Moreover, plant nucleotide-binding leucine-rich repeat protein-mediated virus resistance has been linked to enhanced processing body formation and translational repression of viral RNA. Many interesting questions relate to how the pathways of antiviral RNA silencing leading to viral RNA degradation and/or repression of translation, suppression of RNA silencing and viral RNA translation converge in plants and how different RNA granules and

  4. Plant RNA Regulatory Network and RNA Granules in Virus Infection.

    Science.gov (United States)

    Mäkinen, Kristiina; Lõhmus, Andres; Pollari, Maija

    2017-01-01

    Regulation of post-transcriptional gene expression on mRNA level in eukaryotic cells includes translocation, translation, translational repression, storage, mRNA decay, RNA silencing, and nonsense-mediated decay. These processes are associated with various RNA-binding proteins and cytoplasmic ribonucleoprotein complexes many of which are conserved across eukaryotes. Microscopically visible aggregations formed by ribonucleoprotein complexes are termed RNA granules. Stress granules where the translationally inactive mRNAs are stored and processing bodies where mRNA decay may occur present the most studied RNA granule types. Diverse RNP-granules are increasingly being assigned important roles in viral infections. Although the majority of the molecular level studies on the role of RNA granules in viral translation and replication have been conducted in mammalian systems, some studies link also plant virus infection to RNA granules. An increasing body of evidence indicates that plant viruses require components of stress granules and processing bodies for their replication and translation, but how extensively the cellular mRNA regulatory network is utilized by plant viruses has remained largely enigmatic. Antiviral RNA silencing, which is an important regulator of viral RNA stability and expression in plants, is commonly counteracted by viral suppressors of RNA silencing. Some of the RNA silencing suppressors localize to cellular RNA granules and have been proposed to carry out their suppression functions there. Moreover, plant nucleotide-binding leucine-rich repeat protein-mediated virus resistance has been linked to enhanced processing body formation and translational repression of viral RNA. Many interesting questions relate to how the pathways of antiviral RNA silencing leading to viral RNA degradation and/or repression of translation, suppression of RNA silencing and viral RNA translation converge in plants and how different RNA granules and their individual

  5. RNA-Catalyzed Polymerization and Replication of RNA

    Science.gov (United States)

    Horning, D. P.; Samantha, B.; Tjhung, K. F.; Joyce, G. F.

    2017-07-01

    In an effort to reconstruct RNA-based life, in vitro evolution was used to obtain an RNA polymerase ribozyme that can synthesize a variety of complex functional RNAs and can catalyze the exponential amplification of short RNAs.

  6. Natural RNA circles function as efficient microRNA sponges

    DEFF Research Database (Denmark)

    Hansen, Thomas Birkballe; Jensen, Trine I; Clausen, Bettina Hjelm

    2013-01-01

    MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression that act by direct base pairing to target sites within untranslated regions of messenger RNAs. Recently, miRNA activity has been shown to be affected by the presence of miRNA sponge transcripts, the so-called comp......MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression that act by direct base pairing to target sites within untranslated regions of messenger RNAs. Recently, miRNA activity has been shown to be affected by the presence of miRNA sponge transcripts, the so......-called competing endogenous RNA in humans and target mimicry in plants. We previously identified a highly expressed circular RNA (circRNA) in human and mouse brain. Here we show that this circRNA acts as a miR-7 sponge; we term this circular transcript ciRS-7 (circular RNA sponge for miR-7). ciRS-7 contains more...... sponge, suggesting that miRNA sponge effects achieved by circRNA formation are a general phenomenon. This study serves as the first, to our knowledge, functional analysis of a naturally expressed circRNA....

  7. RNA Interference - Towards RNA becoming a Medicine -42 ...

    Indian Academy of Sciences (India)

    research. A brief history of the development ofRNAi is shown in. Box 2. Mechanism of ... new RNA strand using target RNA as the template and thereby converting it ... thought to excise precursor stRNA from their -70 nt stem loop precursor to ...

  8. Semiautomated improvement of RNA alignments

    DEFF Research Database (Denmark)

    Andersen, Ebbe Sloth; Lind-Thomsen, Allan; Knudsen, Bjarne

    2007-01-01

    connects to external tools to provide a flexible semiautomatic editing environment. A new method, Pcluster, is introduced for dividing the sequences of an RNA alignment into subgroups with secondary structure differences. Pcluster was used to evaluate 574 seed alignments obtained from the Rfam database...... and we identified 71 alignments with significant prediction of inconsistent base pairs and 102 alignments with significant prediction of novel base pairs. Four RNA families were used to illustrate how SARSE can be used to manually or automatically correct the inconsistent base pairs detected by Pcluster......: the mir-399 RNA, vertebrate telomase RNA (vert-TR), bacterial transfer-messenger RNA (tmRNA), and the signal recognition particle (SRP) RNA. The general use of the method is illustrated by the ability to accommodate pseudoknots and handle even large and divergent RNA families. The open architecture...

  9. Comparative RNA genomics

    DEFF Research Database (Denmark)

    Backofen, Rolf; Gorodkin, Jan; Hofacker, Ivo L.

    2018-01-01

    Over the last two decades it has become clear that RNA is much more than just a boring intermediate in protein expression. Ancient RNAs still appear in the core information metabolism and comprise a surprisingly large component in bacterial gene regulation. A common theme with these types of mostly...... small RNAs is their reliance of conserved secondary structures. Large scale sequencing projects, on the other hand, have profoundly changed our understanding of eukaryotic genomes. Pervasively transcribed, they give rise to a plethora of large and evolutionarily extremely flexible noncoding RNAs...... that exert a vastly diverse array of molecule functions. In this chapter we provide a—necessarily incomplete—overview of the current state of comparative analysis of noncoding RNAs, emphasizing computational approaches as a means to gain a global picture of the modern RNA world....

  10. MicroRNA from tuberculosis RNA: A bioinformatics study

    OpenAIRE

    Wiwanitkit, Somsri; Wiwanitkit, Viroj

    2012-01-01

    The role of microRNA in the pathogenesis of pulmonary tuberculosis is the interesting topic in chest medicine at present. Recently, it was proposed that the microRNA can be a useful biomarker for monitoring of pulmonary tuberculosis and might be the important part in pathogenesis of disease. Here, the authors perform a bioinformatics study to assess the microRNA within known tuberculosis RNA. The microRNA part can be detected and this can be important key information in further study of the p...

  11. Genetic relatedness of orbiviruses by RNA-RNA blot hybridization

    International Nuclear Information System (INIS)

    Bodkin, D.K.

    1985-01-01

    RNA-RNA blot hybridization was developed in order to identify type-specific genes among double-stranded (ds) RNA viruses, to assess the genetic relatedness of dsRNA viruses and to classify new strains. Viral dsRNA segments were electrophoresed through 10% polyacrylamide gels, transferred to membranes, and hybridized to [5' 32 P]-pCp labeled genomic RNA from a related strain. Hybridization was performed at 52 0 C, 50% formamide, 5X SSC. Under these conditions heterologous RNA species must share ≥ 74% sequence homology in order to form stable dsRNA hybrids. Cognate genes of nine members of the Palyam serogroup of orbiviruses were identified and their sequence relatedness to the prototype. Palyam virus, was determined. Reciprocal blot hybridizations were performed using radiolabeled genomic RNA of all members of the Palyam serogroup. Unique and variant genes were identified by lack of cross-homology or by weak homology between segments. Since genes 2 and 6 exhibited the highest degree of sequence variability, response to the vertebrate immune system may be a major cause of sequence divergence among members of a single serogroup. Changuinola serogroup isolates were compared by dot-blot hybridization, while Colorado tick fever (CTF) serogroup isolates were compared by the RNA-RNA blot hybridization procedure described for reovirus and Palyam serogroup isolates. Preliminary blot hybridization data were also obtained on the relatedness of members of different Orbivirus serogroups

  12. RNA-SSPT: RNA Secondary Structure Prediction Tools.

    Science.gov (United States)

    Ahmad, Freed; Mahboob, Shahid; Gulzar, Tahsin; Din, Salah U; Hanif, Tanzeela; Ahmad, Hifza; Afzal, Muhammad

    2013-01-01

    The prediction of RNA structure is useful for understanding evolution for both in silico and in vitro studies. Physical methods like NMR studies to predict RNA secondary structure are expensive and difficult. Computational RNA secondary structure prediction is easier. Comparative sequence analysis provides the best solution. But secondary structure prediction of a single RNA sequence is challenging. RNA-SSPT is a tool that computationally predicts secondary structure of a single RNA sequence. Most of the RNA secondary structure prediction tools do not allow pseudoknots in the structure or are unable to locate them. Nussinov dynamic programming algorithm has been implemented in RNA-SSPT. The current studies shows only energetically most favorable secondary structure is required and the algorithm modification is also available that produces base pairs to lower the total free energy of the secondary structure. For visualization of RNA secondary structure, NAVIEW in C language is used and modified in C# for tool requirement. RNA-SSPT is built in C# using Dot Net 2.0 in Microsoft Visual Studio 2005 Professional edition. The accuracy of RNA-SSPT is tested in terms of Sensitivity and Positive Predicted Value. It is a tool which serves both secondary structure prediction and secondary structure visualization purposes.

  13. RNA meets disease in paradise.

    Science.gov (United States)

    Winter, Julia; Roth, Anna; Diederichs, Sven

    2011-01-01

    Getting off the train in Jena-Paradies, 60 participants joined for the 12 (th) Young Scientist Meeting of the German Society for Cell Biology (DGZ) entitled "RNA & Disease". Excellent speakers from around the world, graduate students, postdocs and young group leaders enjoyed a meeting in a familiar atmosphere to exchange inspiring new data and vibrant scientific discussions about the fascinating history and exciting future of non-coding RNA research including microRNA, piRNA and long non-coding RNA as well as their function in cancer, diabetes and neurodegenerative diseases.

  14. From "Cellular" RNA to "Smart" RNA: Multiple Roles of RNA in Genome Stability and Beyond.

    Science.gov (United States)

    Michelini, Flavia; Jalihal, Ameya P; Francia, Sofia; Meers, Chance; Neeb, Zachary T; Rossiello, Francesca; Gioia, Ubaldo; Aguado, Julio; Jones-Weinert, Corey; Luke, Brian; Biamonti, Giuseppe; Nowacki, Mariusz; Storici, Francesca; Carninci, Piero; Walter, Nils G; Fagagna, Fabrizio d'Adda di

    2018-03-30

    Coding for proteins has been considered the main function of RNA since the "central dogma" of biology was proposed. The discovery of noncoding transcripts shed light on additional roles of RNA, ranging from the support of polypeptide synthesis, to the assembly of subnuclear structures, to gene expression modulation. Cellular RNA has therefore been recognized as a central player in often unanticipated biological processes, including genomic stability. This ever-expanding list of functions inspired us to think of RNA as a "smart" phone, which has replaced the older obsolete "cellular" phone. In this review, we summarize the last two decades of advances in research on the interface between RNA biology and genome stability. We start with an account of the emergence of noncoding RNA, and then we discuss the involvement of RNA in DNA damage signaling and repair, telomere maintenance, and genomic rearrangements. We continue with the depiction of single-molecule RNA detection techniques, and we conclude by illustrating the possibilities of RNA modulation in hopes of creating or improving new therapies. The widespread biological functions of RNA have made this molecule a reoccurring theme in basic and translational research, warranting it the transcendence from classically studied "cellular" RNA to "smart" RNA.

  15. Transfer RNA and human disease

    Directory of Open Access Journals (Sweden)

    Jamie A Abbott

    2014-06-01

    Full Text Available Pathological mutations in tRNA genes and tRNA processing enzymes are numerous and result in very complicated clinical phenotypes. Mitochondrial tRNA (mt-tRNA genes are hotspots for pathological mutations and over 200 mt-tRNA mutations have been linked to various disease states. Often these mutations prevent tRNA aminoacylation. Disrupting this primary function affects protein synthesis and the expression, folding, and function of oxidative phosphorylation enzymes. Mitochondrial tRNA mutations manifest in a wide panoply of diseases related to cellular energetics, including COX deficiency (cytochrome C oxidase, mitochondrial myopathy, MERRF (Myoclonic Epilepsy with Ragged Red Fibers, and MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes. Diseases caused by mt-tRNA mutations can also affect very specific tissue types, as in the case of neurosensory non-syndromic hearing loss and pigmentary retinopathy, diabetes mellitus, and hypertrophic cardiomyopathy. Importantly, mitochondrial heteroplasmy plays a role in disease severity and age of onset as well. Not surprisingly, mutations in enzymes that modify cytoplasmic and mitochondrial tRNAs are also linked to a diverse range of clinical phenotypes. In addition to compromised aminoacylation of the tRNAs, mutated modifying enzymes can also impact tRNA expression and abundance, tRNA modifications, tRNA folding, and even tRNA maturation (e.g., splicing. Some of these pathological mutations in tRNAs and processing enzymes are likely to affect non-canonical tRNA functions, and contribute to the diseases without significantly impacting on translation. This chapter will review recent literature on the relation of mitochondrial and cytoplasmic tRNA, and enzymes that process tRNAs, to human disease. We explore the mechanisms involved in the clinical presentation of these various diseases with an emphasis on neurological disease.

  16. Transfer RNA and human disease.

    Science.gov (United States)

    Abbott, Jamie A; Francklyn, Christopher S; Robey-Bond, Susan M

    2014-01-01

    Pathological mutations in tRNA genes and tRNA processing enzymes are numerous and result in very complicated clinical phenotypes. Mitochondrial tRNA (mt-tRNA) genes are "hotspots" for pathological mutations and over 200 mt-tRNA mutations have been linked to various disease states. Often these mutations prevent tRNA aminoacylation. Disrupting this primary function affects protein synthesis and the expression, folding, and function of oxidative phosphorylation enzymes. Mitochondrial tRNA mutations manifest in a wide panoply of diseases related to cellular energetics, including COX deficiency (cytochrome C oxidase), mitochondrial myopathy, MERRF (Myoclonic Epilepsy with Ragged Red Fibers), and MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes). Diseases caused by mt-tRNA mutations can also affect very specific tissue types, as in the case of neurosensory non-syndromic hearing loss and pigmentary retinopathy, diabetes mellitus, and hypertrophic cardiomyopathy. Importantly, mitochondrial heteroplasmy plays a role in disease severity and age of onset as well. Not surprisingly, mutations in enzymes that modify cytoplasmic and mitochondrial tRNAs are also linked to a diverse range of clinical phenotypes. In addition to compromised aminoacylation of the tRNAs, mutated modifying enzymes can also impact tRNA expression and abundance, tRNA modifications, tRNA folding, and even tRNA maturation (e.g., splicing). Some of these pathological mutations in tRNAs and processing enzymes are likely to affect non-canonical tRNA functions, and contribute to the diseases without significantly impacting on translation. This chapter will review recent literature on the relation of mitochondrial and cytoplasmic tRNA, and enzymes that process tRNAs, to human disease. We explore the mechanisms involved in the clinical presentation of these various diseases with an emphasis on neurological disease.

  17. RNA Thermodynamic Structural Entropy.

    Science.gov (United States)

    Garcia-Martin, Juan Antonio; Clote, Peter

    2015-01-01

    Conformational entropy for atomic-level, three dimensional biomolecules is known experimentally to play an important role in protein-ligand discrimination, yet reliable computation of entropy remains a difficult problem. Here we describe the first two accurate and efficient algorithms to compute the conformational entropy for RNA secondary structures, with respect to the Turner energy model, where free energy parameters are determined from UV absorption experiments. An algorithm to compute the derivational entropy for RNA secondary structures had previously been introduced, using stochastic context free grammars (SCFGs). However, the numerical value of derivational entropy depends heavily on the chosen context free grammar and on the training set used to estimate rule probabilities. Using data from the Rfam database, we determine that both of our thermodynamic methods, which agree in numerical value, are substantially faster than the SCFG method. Thermodynamic structural entropy is much smaller than derivational entropy, and the correlation between length-normalized thermodynamic entropy and derivational entropy is moderately weak to poor. In applications, we plot the structural entropy as a function of temperature for known thermoswitches, such as the repression of heat shock gene expression (ROSE) element, we determine that the correlation between hammerhead ribozyme cleavage activity and total free energy is improved by including an additional free energy term arising from conformational entropy, and we plot the structural entropy of windows of the HIV-1 genome. Our software RNAentropy can compute structural entropy for any user-specified temperature, and supports both the Turner'99 and Turner'04 energy parameters. It follows that RNAentropy is state-of-the-art software to compute RNA secondary structure conformational entropy. Source code is available at https://github.com/clotelab/RNAentropy/; a full web server is available at http

  18. RNA Thermodynamic Structural Entropy.

    Directory of Open Access Journals (Sweden)

    Juan Antonio Garcia-Martin

    Full Text Available Conformational entropy for atomic-level, three dimensional biomolecules is known experimentally to play an important role in protein-ligand discrimination, yet reliable computation of entropy remains a difficult problem. Here we describe the first two accurate and efficient algorithms to compute the conformational entropy for RNA secondary structures, with respect to the Turner energy model, where free energy parameters are determined from UV absorption experiments. An algorithm to compute the derivational entropy for RNA secondary structures had previously been introduced, using stochastic context free grammars (SCFGs. However, the numerical value of derivational entropy depends heavily on the chosen context free grammar and on the training set used to estimate rule probabilities. Using data from the Rfam database, we determine that both of our thermodynamic methods, which agree in numerical value, are substantially faster than the SCFG method. Thermodynamic structural entropy is much smaller than derivational entropy, and the correlation between length-normalized thermodynamic entropy and derivational entropy is moderately weak to poor. In applications, we plot the structural entropy as a function of temperature for known thermoswitches, such as the repression of heat shock gene expression (ROSE element, we determine that the correlation between hammerhead ribozyme cleavage activity and total free energy is improved by including an additional free energy term arising from conformational entropy, and we plot the structural entropy of windows of the HIV-1 genome. Our software RNAentropy can compute structural entropy for any user-specified temperature, and supports both the Turner'99 and Turner'04 energy parameters. It follows that RNAentropy is state-of-the-art software to compute RNA secondary structure conformational entropy. Source code is available at https://github.com/clotelab/RNAentropy/; a full web server is available at http

  19. Identifying microRNA/mRNA dysregulations in ovarian cancer.

    Science.gov (United States)

    Miles, Gregory D; Seiler, Michael; Rodriguez, Lorna; Rajagopal, Gunaretnam; Bhanot, Gyan

    2012-03-27

    MicroRNAs are a class of noncoding RNA molecules that co-regulate the expression of multiple genes via mRNA transcript degradation or translation inhibition. Since they often target entire pathways, they may be better drug targets than genes or proteins. MicroRNAs are known to be dysregulated in many tumours and associated with aggressive or poor prognosis phenotypes. Since they regulate mRNA in a tissue specific manner, their functional mRNA targets are poorly understood. In previous work, we developed a method to identify direct mRNA targets of microRNA using patient matched microRNA/mRNA expression data using an anti-correlation signature. This method, applied to clear cell Renal Cell Carcinoma (ccRCC), revealed many new regulatory pathways compromised in ccRCC. In the present paper, we apply this method to identify dysregulated microRNA/mRNA mechanisms in ovarian cancer using data from The Cancer Genome Atlas (TCGA). TCGA Microarray data was normalized and samples whose class labels (tumour or normal) were ambiguous with respect to consensus ensemble K-Means clustering were removed. Significantly anti-correlated and correlated genes/microRNA differentially expressed between tumour and normal samples were identified. TargetScan was used to identify gene targets of microRNA. We identified novel microRNA/mRNA mechanisms in ovarian cancer. For example, the expression level of RAD51AP1 was found to be strongly anti-correlated with the expression of hsa-miR-140-3p, which was significantly down-regulated in the tumour samples. The anti-correlation signature was present separately in the tumour and normal samples, suggesting a direct causal dysregulation of RAD51AP1 by hsa-miR-140-3p in the ovary. Other pairs of potentially biological relevance include: hsa-miR-145/E2F3, hsa-miR-139-5p/TOP2A, and hsa-miR-133a/GCLC. We also identified sets of positively correlated microRNA/mRNA pairs that are most likely result from indirect regulatory mechanisms. Our findings identify

  20. RNA-PAIRS: RNA probabilistic assignment of imino resonance shifts

    International Nuclear Information System (INIS)

    Bahrami, Arash; Clos, Lawrence J.; Markley, John L.; Butcher, Samuel E.; Eghbalnia, Hamid R.

    2012-01-01

    The significant biological role of RNA has further highlighted the need for improving the accuracy, efficiency and the reach of methods for investigating RNA structure and function. Nuclear magnetic resonance (NMR) spectroscopy is vital to furthering the goals of RNA structural biology because of its distinctive capabilities. However, the dispersion pattern in the NMR spectra of RNA makes automated resonance assignment, a key step in NMR investigation of biomolecules, remarkably challenging. Herein we present RNA Probabilistic Assignment of Imino Resonance Shifts (RNA-PAIRS), a method for the automated assignment of RNA imino resonances with synchronized verification and correction of predicted secondary structure. RNA-PAIRS represents an advance in modeling the assignment paradigm because it seeds the probabilistic network for assignment with experimental NMR data, and predicted RNA secondary structure, simultaneously and from the start. Subsequently, RNA-PAIRS sets in motion a dynamic network that reverberates between predictions and experimental evidence in order to reconcile and rectify resonance assignments and secondary structure information. The procedure is halted when assignments and base-parings are deemed to be most consistent with observed crosspeaks. The current implementation of RNA-PAIRS uses an initial peak list derived from proton-nitrogen heteronuclear multiple quantum correlation ( 1 H– 15 N 2D HMQC) and proton–proton nuclear Overhauser enhancement spectroscopy ( 1 H– 1 H 2D NOESY) experiments. We have evaluated the performance of RNA-PAIRS by using it to analyze NMR datasets from 26 previously studied RNAs, including a 111-nucleotide complex. For moderately sized RNA molecules, and over a range of comparatively complex structural motifs, the average assignment accuracy exceeds 90%, while the average base pair prediction accuracy exceeded 93%. RNA-PAIRS yielded accurate assignments and base pairings consistent with imino resonances for a

  1. RNA-PAIRS: RNA probabilistic assignment of imino resonance shifts

    Energy Technology Data Exchange (ETDEWEB)

    Bahrami, Arash; Clos, Lawrence J.; Markley, John L.; Butcher, Samuel E. [National Magnetic Resonance Facility at Madison (United States); Eghbalnia, Hamid R., E-mail: eghbalhd@uc.edu [University of Cincinnati, Department of Molecular and Cellular Physiology (United States)

    2012-04-15

    The significant biological role of RNA has further highlighted the need for improving the accuracy, efficiency and the reach of methods for investigating RNA structure and function. Nuclear magnetic resonance (NMR) spectroscopy is vital to furthering the goals of RNA structural biology because of its distinctive capabilities. However, the dispersion pattern in the NMR spectra of RNA makes automated resonance assignment, a key step in NMR investigation of biomolecules, remarkably challenging. Herein we present RNA Probabilistic Assignment of Imino Resonance Shifts (RNA-PAIRS), a method for the automated assignment of RNA imino resonances with synchronized verification and correction of predicted secondary structure. RNA-PAIRS represents an advance in modeling the assignment paradigm because it seeds the probabilistic network for assignment with experimental NMR data, and predicted RNA secondary structure, simultaneously and from the start. Subsequently, RNA-PAIRS sets in motion a dynamic network that reverberates between predictions and experimental evidence in order to reconcile and rectify resonance assignments and secondary structure information. The procedure is halted when assignments and base-parings are deemed to be most consistent with observed crosspeaks. The current implementation of RNA-PAIRS uses an initial peak list derived from proton-nitrogen heteronuclear multiple quantum correlation ({sup 1}H-{sup 15}N 2D HMQC) and proton-proton nuclear Overhauser enhancement spectroscopy ({sup 1}H-{sup 1}H 2D NOESY) experiments. We have evaluated the performance of RNA-PAIRS by using it to analyze NMR datasets from 26 previously studied RNAs, including a 111-nucleotide complex. For moderately sized RNA molecules, and over a range of comparatively complex structural motifs, the average assignment accuracy exceeds 90%, while the average base pair prediction accuracy exceeded 93%. RNA-PAIRS yielded accurate assignments and base pairings consistent with imino

  2. RNA SURVEILLANCE– AN EMERGING ROLE FOR RNA REGULATORY NETWORKS IN AGING

    OpenAIRE

    Montano, Monty; Long, Kimberly

    2010-01-01

    In this review, we describe recent advances in the field of RNA regulatory biology and relate these advances to aging science. We introduce a new term, RNA surveillance, an RNA regulatory process that is conserved in metazoans, and describe how RNA surveillance represents molecular cross-talk between two emerging RNA regulatory systems – RNA interference and RNA editing. We discuss how RNA surveillance mechanisms influence mRNA and microRNA expression and activity during lifespan. Additionall...

  3. On RNA-RNA interaction structures of fixed topological genus.

    Science.gov (United States)

    Fu, Benjamin M M; Han, Hillary S W; Reidys, Christian M

    2015-04-01

    Interacting RNA complexes are studied via bicellular maps using a filtration via their topological genus. Our main result is a new bijection for RNA-RNA interaction structures and a linear time uniform sampling algorithm for RNA complexes of fixed topological genus. The bijection allows to either reduce the topological genus of a bicellular map directly, or to lose connectivity by decomposing the complex into a pair of single stranded RNA structures. Our main result is proved bijectively. It provides an explicit algorithm of how to rewire the corresponding complexes and an unambiguous decomposition grammar. Using the concept of genus induction, we construct bicellular maps of fixed topological genus g uniformly in linear time. We present various statistics on these topological RNA complexes and compare our findings with biological complexes. Furthermore we show how to construct loop-energy based complexes using our decomposition grammar. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. antaRNA: ant colony-based RNA sequence design.

    Science.gov (United States)

    Kleinkauf, Robert; Mann, Martin; Backofen, Rolf

    2015-10-01

    RNA sequence design is studied at least as long as the classical folding problem. Although for the latter the functional fold of an RNA molecule is to be found ,: inverse folding tries to identify RNA sequences that fold into a function-specific target structure. In combination with RNA-based biotechnology and synthetic biology ,: reliable RNA sequence design becomes a crucial step to generate novel biochemical components. In this article ,: the computational tool antaRNA is presented. It is capable of compiling RNA sequences for a given structure that comply in addition with an adjustable full range objective GC-content distribution ,: specific sequence constraints and additional fuzzy structure constraints. antaRNA applies ant colony optimization meta-heuristics and its superior performance is shown on a biological datasets. http://www.bioinf.uni-freiburg.de/Software/antaRNA CONTACT: backofen@informatik.uni-freiburg.de Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press.

  5. RNA İNTERFERANS (RNAİ)

    OpenAIRE

    GÜNDOĞDU, Ramazan; ÇELİK, Venhar

    2009-01-01

    RNA interferans, uygun çift zincirli RNA’nın hücreye girdiği zaman, endojenik komplementer mRNA dizisinin parçalanmasına yol açan, transkripsiyon sonrası gen susturma mekanizmasıdır. RNA interferans, Dicer adı verilen bir RNase III enzimi tarafından çift zincirli RNA’nın küçük engelleyici RNA’lara (siRNA) kesilmesi ile başlamaktadır. Bu siRNA’lar daha sonra, bir multiprotein-RNA nükleaz kompleksi olan, RNA- indükleyici baskılama kompleksine (RISC) bağlanır. RISC, siRNA’ları komplementer mRNA’...

  6. Radiation sensitivity of messenger RNA

    International Nuclear Information System (INIS)

    Ponta, H.; Pfennig-Yeh, M.L.; Herrlich, P.; Karlsruhe Univ.; Wagner, E.F.; Schweiger, M.

    1979-01-01

    Messenger RNA function is inactivated by irradiation with ultraviolet light. A unit length mRNA (in bases) is 2-3 times more sensitive than a unit length of DNA (in base pairs) with respect to the inactivation of template function. These data stem from four experimental systems all of which do not repair DNA: the translation of E. coli mRNA in rifampicin-treated cells, of T7 mRNA in infected E.coli, of f2 phage RNA in vivo, and of stable mRNA in chromosomeless minicells. The comparison of relative sensitivities to UV is relevant to the technique of UV mapping of transcription units which enjoys increasing popularity in pro- and eukaryotic genetic research. (orig.) [de

  7. Radiation sensitivity of messenger RNA

    Energy Technology Data Exchange (ETDEWEB)

    Ponta, H; Pfennig-Yeh, M L; Herrlich, P [Kernforschungszentrum Karlsruhe G.m.b.H. (Germany, F.R.). Inst. fuer Genetik und Toxikologie von Spaltstoffen; Karlsruhe Univ. (TH) (Germany, F.R.). Inst. fuer Genetik); Wagner, E F; Schweiger, M [Innsbruck Univ. (Austria). Inst. fuer Biochemie

    1979-08-01

    Messenger RNA function is inactivated by irradiation with ultraviolet light. A unit length mRNA (in bases) is 2-3 times more sensitive than a unit length of DNA (in base pairs) with respect to the inactivation of template function. These data stem from four experimental systems all of which do not repair DNA: the translation of E. coli mRNA in rifampicin-treated cells, of T7 mRNA in infected E.coli, of f2 phage RNA in vivo, and of stable mRNA in chromosomeless minicells. The comparison of relative sensitivities to UV is relevant to the technique of UV mapping of transcription units which enjoys increasing popularity in pro- and eukaryotic genetic research.

  8. Generation of a non-transmissive Borna disease virus vector lacking both matrix and glycoprotein genes.

    Science.gov (United States)

    Fujino, Kan; Yamamoto, Yusuke; Daito, Takuji; Makino, Akiko; Honda, Tomoyuki; Tomonaga, Keizo

    2017-09-01

    Borna disease virus (BoDV), a prototype of mammalian bornavirus, is a non-segmented, negative strand RNA virus that often causes severe neurological disorders in infected animals, including horses and sheep. Unique among animal RNA viruses, BoDV transcribes and replicates non-cytopathically in the cell nucleus, leading to establishment of long-lasting persistent infection. This striking feature of BoDV indicates its potential as an RNA virus vector system. It has previously been demonstrated by our team that recombinant BoDV (rBoDV) lacking an envelope glycoprotein (G) gene develops persistent infections in transduced cells without loss of the viral genome. In this study, a novel non-transmissive rBoDV, rBoDV ΔMG, which lacks both matrix (M) and G genes in the genome, is reported. rBoDV-ΔMG expressing green fluorescence protein (GFP), rBoDV ΔMG-GFP, was efficiently generated in Vero/MG cells stably expressing both BoDV M and G proteins. Infection with rBoDV ΔMG-GFP was persistently maintained in the parent Vero cells without propagation within cell culture. The optimal ratio of M and G for efficient viral particle production by transient transfection of M and G expression plasmids into cells persistently infected with rBoDV ΔMG-GFP was also demonstrated. These findings indicate that the rBoDV ΔMG-based BoDV vector may provide an extremely safe virus vector system and could be a novel strategy for investigating the function of M and G proteins and the host range of bornaviruses. © 2017 The Societies and John Wiley & Sons Australia, Ltd.

  9. RNase-assisted RNA chromatography

    Science.gov (United States)

    Michlewski, Gracjan; Cáceres, Javier F.

    2010-01-01

    RNA chromatography combined with mass spectrometry represents a widely used experimental approach to identify RNA-binding proteins that recognize specific RNA targets. An important drawback of most of these protocols is the high background due to direct or indirect nonspecific binding of cellular proteins to the beads. In many cases this can hamper the detection of individual proteins due to their low levels and/or comigration with contaminating proteins. Increasing the salt concentration during washing steps can reduce background, but at the cost of using less physiological salt concentrations and the likely loss of important RNA-binding proteins that are less stringently bound to a given RNA, as well as the disassembly of protein or ribonucleoprotein complexes. Here, we describe an improved RNA chromatography method that relies on the use of a cocktail of RNases in the elution step. This results in the release of proteins specifically associated with the RNA ligand and almost complete elimination of background noise, allowing a more sensitive and thorough detection of RNA-binding proteins recognizing a specific RNA transcript. PMID:20571124

  10. RNA interference in Lepidoptera

    DEFF Research Database (Denmark)

    Terenius, Ole; Papanicolaou, Alexie; Garbutt, Jennie S.

    2011-01-01

    in RNAi experiments in Lepidoptera are discussed. The review also points to a need to further investigate the mechanism of RNAi in lepidopteran insects and its possible connection to the innate immune response. Our general understanding of RNAi in Lepidoptera will be further aided in the future as our...... experiments have not been collected in such a way that they are possible to analyze. In this review, we have collected detailed data from more than 150 experiments including all to date published and many unpublished experiments. Despite a large variation in the data, trends that are found are that RNAi...... is particularly successful in the family Saturniidae and in genes involved in immunity. On the contrary, gene expression in epidermal tissues seems to be most difficult to silence. In addition, gene silencing by feeding dsRNA requires high concentrations for success. Possible causes for the variability of success...

  11. Detection of negative and positive RNA strand of poliovirus Sabin 1 and echovirus E19 by a stem-loop reverse transcription PCR.

    Science.gov (United States)

    Fikatas, A; Dimitriou, T G; Kyriakopoulou, Z; Moschonas, G D; Amoutzias, G D; Mossialos, D; Gartzonika, C; Levidiotou-Stefanou, S; Markoulatos, P

    2017-09-01

    In this report a strand specific RT-PCR was established for the detection of the replicative negative RNA strand of poliovirus sabin 1 (Sabin1) and Echovirus 19 (E19) strains. The key for the successful conduction of the assay was the use of a specific reverse transcription primer targeting the 5'-UTR of enteroviruses that consisted of a stem-loop structure at the 5'-end and an enteroviral-specific sequence at the 3'-end. The stem loop RT-PCR was found to be an accurate and sensitive method, detecting even 10 -2 CCID 50 of poliovirus sabin 1 (Sabin1) and E19 strains 6 h postinfection (p.i.), while CPE appeared 3 days later. This assay was also validated in SiHa and Caski cell lines that are not used for the detection of enteroviruses. The negative RNA strand was detected 6 h and 12 h p.i. in SiHa and Caski cells, when these cell lines were inoculated with 10 5 and 1 CCID 50 respectively, whereas CPE was observed 5 days p.i for SiHa cells and 8 days p.i for Caski cells and that only at 10 5 CCID 50 . The results show that this approach may be used for replacing the time-consuming cell cultures in order to detect the active replication of enteroviruses. Enteroviruses are positive stranded RNA viruses that may cause severe diseases. The conventional method for detection of active viral replication involves virus isolation in sensitive cell cultures followed by titration and seroneutralization. In this report, we describe the use of a stem-loop secondary structured oligonucleotide in RT-PCR assay for the detection of the replicative negative strand of the positive-stranded RNA of poliovirus sabin 1 and E19 strains. This approach proved to be a useful tool that may be used for replacing the time-consuming cell culture assays in order to detect the active replication of enteroviruses. © 2017 The Society for Applied Microbiology.

  12. Concepts and introduction to RNA bioinformatics

    DEFF Research Database (Denmark)

    Gorodkin, Jan; Hofacker, Ivo L.; Ruzzo, Walter L.

    2014-01-01

    RNA bioinformatics and computational RNA biology have emerged from implementing methods for predicting the secondary structure of single sequences. The field has evolved to exploit multiple sequences to take evolutionary information into account, such as compensating (and structure preserving) base...... for interactions between RNA and proteins.Here, we introduce the basic concepts of predicting RNA secondary structure relevant to the further analyses of RNA sequences. We also provide pointers to methods addressing various aspects of RNA bioinformatics and computational RNA biology....

  13. Identification of Subtype Specific miRNA-mRNA Functional Regulatory Modules in Matched miRNA-mRNA Expression Data: Multiple Myeloma as a Case

    OpenAIRE

    Zhang, Yunpeng; Liu, Wei; Xu, Yanjun; Li, Chunquan; Wang, Yingying; Yang, Haixiu; Zhang, Chunlong; Su, Fei; Li, Yixue; Li, Xia

    2015-01-01

    Identification of miRNA-mRNA modules is an important step to elucidate their combinatorial effect on the pathogenesis and mechanisms underlying complex diseases. Current identification methods primarily are based upon miRNA-target information and matched miRNA and mRNA expression profiles. However, for heterogeneous diseases, the miRNA-mRNA regulatory mechanisms may differ between subtypes, leading to differences in clinical behavior. In order to explore the pathogenesis of each subtype, it i...

  14. Bifurcations in the interplay of messenger RNA, protein and nonprotein coding RNA

    International Nuclear Information System (INIS)

    Zhdanov, Vladimir P

    2008-01-01

    The interplay of messenger RNA (mRNA), protein, produced via translation of this RNA, and nonprotein coding RNA (ncRNA) may include regulation of the ncRNA production by protein and (i) ncRNA-protein association resulting in suppression of the protein regulatory activity or (ii) ncRNA-mRNA association resulting in degradation of the miRNA-mRNA complex. The kinetic models describing these two scenarios are found to predict bistability provided that protein suppresses the ncRNA formation

  15. 34A, miRNA-944, miRNA-101 and miRNA-218 in cervical cancer

    African Journals Online (AJOL)

    RNAs (21 - 24 nucleotides in length) that are critical for many important processes such as development, ... RNA extraction and reverse transcription. Total RNA was extracted from each of the experimental groups using ... used as an endogenous control to normalize the expression of miRNA-143, miRNA-34A, miRNA-.

  16. Nuclear Export of Messenger RNA

    Directory of Open Access Journals (Sweden)

    Jun Katahira

    2015-03-01

    Full Text Available Transport of messenger RNA (mRNA from the nucleus to the cytoplasm is an essential step of eukaryotic gene expression. In the cell nucleus, a precursor mRNA undergoes a series of processing steps, including capping at the 5' ends, splicing and cleavage/polyadenylation at the 3' ends. During this process, the mRNA associates with a wide variety of proteins, forming a messenger ribonucleoprotein (mRNP particle. Association with factors involved in nuclear export also occurs during transcription and processing, and thus nuclear export is fully integrated into mRNA maturation. The coupling between mRNA maturation and nuclear export is an important mechanism for providing only fully functional and competent mRNA to the cytoplasmic translational machinery, thereby ensuring accuracy and swiftness of gene expression. This review describes the molecular mechanism of nuclear mRNA export mediated by the principal transport factors, including Tap-p15 and the TREX complex.

  17. RNA viruses in the sea.

    Science.gov (United States)

    Lang, Andrew S; Rise, Matthew L; Culley, Alexander I; Steward, Grieg F

    2009-03-01

    Viruses are ubiquitous in the sea and appear to outnumber all other forms of marine life by at least an order of magnitude. Through selective infection, viruses influence nutrient cycling, community structure, and evolution in the ocean. Over the past 20 years we have learned a great deal about the diversity and ecology of the viruses that constitute the marine virioplankton, but until recently the emphasis has been on DNA viruses. Along with expanding knowledge about RNA viruses that infect important marine animals, recent isolations of RNA viruses that infect single-celled eukaryotes and molecular analyses of the RNA virioplankton have revealed that marine RNA viruses are novel, widespread, and genetically diverse. Discoveries in marine RNA virology are broadening our understanding of the biology, ecology, and evolution of viruses, and the epidemiology of viral diseases, but there is still much that we need to learn about the ecology and diversity of RNA viruses before we can fully appreciate their contributions to the dynamics of marine ecosystems. As a step toward making sense of how RNA viruses contribute to the extraordinary viral diversity in the sea, we summarize in this review what is currently known about RNA viruses that infect marine organisms.

  18. Nuclear Export of Messenger RNA

    Science.gov (United States)

    Katahira, Jun

    2015-01-01

    Transport of messenger RNA (mRNA) from the nucleus to the cytoplasm is an essential step of eukaryotic gene expression. In the cell nucleus, a precursor mRNA undergoes a series of processing steps, including capping at the 5' ends, splicing and cleavage/polyadenylation at the 3' ends. During this process, the mRNA associates with a wide variety of proteins, forming a messenger ribonucleoprotein (mRNP) particle. Association with factors involved in nuclear export also occurs during transcription and processing, and thus nuclear export is fully integrated into mRNA maturation. The coupling between mRNA maturation and nuclear export is an important mechanism for providing only fully functional and competent mRNA to the cytoplasmic translational machinery, thereby ensuring accuracy and swiftness of gene expression. This review describes the molecular mechanism of nuclear mRNA export mediated by the principal transport factors, including Tap-p15 and the TREX complex. PMID:25836925

  19. Transfecting Human Monocytes with RNA.

    Science.gov (United States)

    Dannull, Jens; Nair, Smita K

    2016-01-01

    Targeting monocytes as a delivery system for drugs or nucleic acids, and thereby harnessing their natural tissue-infiltrating capacity, has become an area of intense investigation in both basic and clinical research. Herein we describe an efficient method to deliver mRNA (messenger RNA) or siRNA (small interfering RNA) into human monocytes by electroporation. This method can be applied in the laboratory to monocytes isolated via magnetic bead-based techniques, or in a clinical setting using monocytes that were collected via counterflow centrifugation elutriation using the Elutra(®) Cell Separation System. We further demonstrate that electroporation of monocytes with RNA represents a robust and highly relevant approach to modify monocytes for cell-based therapies. Last, the procedure described can readily be adapted to monocytes from different species, hence facilitating research in animal models.

  20. Fast prediction of RNA-RNA interaction using heuristic algorithm.

    Science.gov (United States)

    Montaseri, Soheila

    2015-01-01

    Interaction between two RNA molecules plays a crucial role in many medical and biological processes such as gene expression regulation. In this process, an RNA molecule prohibits the translation of another RNA molecule by establishing stable interactions with it. Some algorithms have been formed to predict the structure of the RNA-RNA interaction. High computational time is a common challenge in most of the presented algorithms. In this context, a heuristic method is introduced to accurately predict the interaction between two RNAs based on minimum free energy (MFE). This algorithm uses a few dot matrices for finding the secondary structure of each RNA and binding sites between two RNAs. Furthermore, a parallel version of this method is presented. We describe the algorithm's concurrency and parallelism for a multicore chip. The proposed algorithm has been performed on some datasets including CopA-CopT, R1inv-R2inv, Tar-Tar*, DIS-DIS, and IncRNA54-RepZ in Escherichia coli bacteria. The method has high validity and efficiency, and it is run in low computational time in comparison to other approaches.

  1. Generation of miRNA sponge constructs

    NARCIS (Netherlands)

    Kluiver, Joost; Slezak-Prochazka, Izabella; Smigielska-Czepiel, Katarzyna; Halsema, Nancy; Kroesen, Bart-Jan; van den Berg, Anke

    2012-01-01

    MicroRNA (miRNA) sponges are RNA molecules with repeated miRNA antisense sequences that can sequester miRNAs from their endogenous targets and thus serve as a decoy. Stably expressed miRNA sponges are especially valuable for long-term loss-of-function studies and can be used in vitro and in vivo. We

  2. microRNA-independent recruitment of Argonaute 1 to nanos mRNA through the Smaug RNA-binding protein

    OpenAIRE

    Pinder, Benjamin D; Smibert, Craig A

    2012-01-01

    Argonaute 1 directly interacts with the RNA binding protein Smaug in Drosophila, is thereby recruited to the Smaug target nanos mRNA and is required for Smaug-mediated translational repression of the nanos mRNA.

  3. IntaRNA 2.0: enhanced and customizable prediction of RNA-RNA interactions.

    Science.gov (United States)

    Mann, Martin; Wright, Patrick R; Backofen, Rolf

    2017-07-03

    The IntaRNA algorithm enables fast and accurate prediction of RNA-RNA hybrids by incorporating seed constraints and interaction site accessibility. Here, we introduce IntaRNAv2, which enables enhanced parameterization as well as fully customizable control over the prediction modes and output formats. Based on up to date benchmark data, the enhanced predictive quality is shown and further improvements due to more restrictive seed constraints are highlighted. The extended web interface provides visualizations of the new minimal energy profiles for RNA-RNA interactions. These allow a detailed investigation of interaction alternatives and can reveal potential interaction site multiplicity. IntaRNAv2 is freely available (source and binary), and distributed via the conda package manager. Furthermore, it has been included into the Galaxy workflow framework and its already established web interface enables ad hoc usage. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  4. Direct, rapid RNA sequence analysis

    International Nuclear Information System (INIS)

    Peattie, D.A.

    1987-01-01

    The original methods of RNA sequence analysis were based on enzymatic production and chromatographic separation of overlapping oligonucleotide fragments from within an RNA molecule followed by identification of the mononucleotides comprising the oligomer. Over the past decade the field of nucleic acid sequencing has changed dramatically, however, and RNA molecules now can be sequenced in a variety of more streamlined fashions. Most of the more recent advances in RNA sequencing have involved one-dimensional electrophoretic separation of 32 P-end-labeled oligoribonucleotides on polyacrylamide gels. In this chapter the author discusses two of these methods for determining the nucleotide sequences of RNA molecules rapidly: the chemical method and the enzymatic method. Both methods are direct and degradative, i.e., they rely on fragmatic and chemical approaches should be utilized. The single-strand-specific ribonucleases (A, T 1 , T 2 , and S 1 ) provide an efficient means to locate double-helical regions rapidly, and the chemical reactions provide a means to determine the RNA sequence within these regions. In addition, the chemical reactions allow one to assign interactions to specific atoms and to distinguish secondary interactions from tertiary ones. If the RNA molecule is small enough to be sequenced directly by the enzymatic or chemical method, the probing reactions can be done easily at the same time as sequencing reactions

  5. Cofactors in the RNA World

    Science.gov (United States)

    Ditzler, Mark A.

    2014-01-01

    RNA world theories figure prominently in many scenarios for the origin and early evolution of life. These theories posit that RNA molecules played a much larger role in ancient biology than they do now, acting both as the dominant biocatalysts and as the repository of genetic information. Many features of modern RNA biology are potential examples of molecular fossils from an RNA world, such as the pervasive involvement of nucleotides in coenzymes, the existence of natural aptamers that bind these coenzymes, the existence of natural ribozymes, a biosynthetic pathway in which deoxynucleotides are produced from ribonucleotides, and the central role of ribosomal RNA in protein synthesis in the peptidyl transferase center of the ribosome. Here, we uses both a top-down approach that evaluates RNA function in modern biology and a bottom-up approach that examines the capacities of RNA independent of modern biology. These complementary approaches exploit multiple in vitro evolution techniques coupled with high-throughput sequencing and bioinformatics analysis. Together these complementary approaches advance our understanding of the most primitive organisms, their early evolution, and their eventual transition to modern biochemistry.

  6. Efficient RNA structure comparison algorithms.

    Science.gov (United States)

    Arslan, Abdullah N; Anandan, Jithendar; Fry, Eric; Monschke, Keith; Ganneboina, Nitin; Bowerman, Jason

    2017-12-01

    Recently proposed relative addressing-based ([Formula: see text]) RNA secondary structure representation has important features by which an RNA structure database can be stored into a suffix array. A fast substructure search algorithm has been proposed based on binary search on this suffix array. Using this substructure search algorithm, we present a fast algorithm that finds the largest common substructure of given multiple RNA structures in [Formula: see text] format. The multiple RNA structure comparison problem is NP-hard in its general formulation. We introduced a new problem for comparing multiple RNA structures. This problem has more strict similarity definition and objective, and we propose an algorithm that solves this problem efficiently. We also develop another comparison algorithm that iteratively calls this algorithm to locate nonoverlapping large common substructures in compared RNAs. With the new resulting tools, we improved the RNASSAC website (linked from http://faculty.tamuc.edu/aarslan ). This website now also includes two drawing tools: one specialized for preparing RNA substructures that can be used as input by the search tool, and another one for automatically drawing the entire RNA structure from a given structure sequence.

  7. Structure of the Paramyxovirus Parainfluenza Virus 5 Nucleoprotein in Complex with an Amino-Terminal Peptide of the Phosphoprotein

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, Megha; Leser, George P.; Kors, Christopher A.; Lamb, Robert A.; Sundquist, Wesley I.

    2017-12-13

    Parainfluenza virus 5 (PIV5) belongs to the familyParamyxoviridae, which consists of enveloped viruses with a nonsegmented negative-strand RNA genome encapsidated by the nucleoprotein (N). Paramyxovirus replication is regulated by the phosphoprotein (P) through protein-protein interactions with N and the RNA polymerase (L). The chaperone activity of P is essential to maintain the unassembled RNA-free form of N in order to prevent nonspecific RNA binding and premature N oligomerization. Here, we determined the crystal structure of unassembled PIV5 N in complex with a P peptide (N0P) derived from the N terminus of P (P50) at 2.65 Å. The PIV5 N0P consists of two domains: an N-terminal domain (NTD) and a C-terminal domain (CTD) separated by a hinge region. The cleft at the hinge region of RNA-bound PIV5 N was previously shown to be an RNA binding site. The N0P structure shows that the P peptide binds to the CTD of N and extends toward the RNA binding site to inhibit N oligomerization and, hence, RNA binding. Binding of P peptide also keeps the PIV5 N in the open form. A molecular dynamics (MD) analysis of both the open and closed forms of N shows the flexibility of the CTD and the preference of the N protein to be in an open conformation. The gradual opening of the hinge region, to release the RNA, was also observed. Together, these results advance our knowledge of the conformational swapping of N required for the highly regulated paramyxovirus replication.

    IMPORTANCEParamyxovirus replication is regulated by the interaction of P with N and L proteins. Here, we report the crystal structure of unassembled parainfluenza virus 5 (PIV5) N chaperoned with P peptide. Our results provide a detailed understanding of the binding of P to N. The conformational switching of N between closed and open forms during its initial interaction with P, as well as

  8. Identification of Interferon-Stimulated Gene Proteins That Inhibit Human Parainfluenza Virus Type 3.

    Science.gov (United States)

    Rabbani, M A G; Ribaudo, Michael; Guo, Ju-Tao; Barik, Sailen

    2016-12-15

    A major arm of cellular innate immunity is type I interferon (IFN), represented by IFN-α and IFN-β. Type I IFN transcriptionally induces a large number of cellular genes, collectively known as IFN-stimulated gene (ISG) proteins, which act as antivirals. The IFIT (interferon-induced proteins with tetratricopeptide repeats) family proteins constitute a major subclass of ISG proteins and are characterized by multiple tetratricopeptide repeats (TPRs). In this study, we have interrogated IFIT proteins for the ability to inhibit the growth of human parainfluenza virus type 3 (PIV3), a nonsegmented negative-strand RNA virus of the Paramyxoviridae family and a major cause of respiratory disease in children. We found that IFIT1 significantly inhibited PIV3, whereas IFIT2, IFIT3, and IFIT5 were less effective or not at all. In further screening a set of ISG proteins we discovered that several other such proteins also inhibited PIV3, including IFITM1, IDO (indoleamine 2,3-dioxygenase), PKR (protein kinase, RNA activated), and viperin (virus inhibitory protein, endoplasmic reticulum associated, interferon inducible)/Cig5. The antiviral effect of IDO, the enzyme that catalyzes the first step of tryptophan degradation, could be counteracted by tryptophan. These results advance our knowledge of diverse ISG proteins functioning as antivirals and may provide novel approaches against PIV3. The innate immunity of the host, typified by interferon (IFN), is a major antiviral defense. IFN inhibits virus growth by inducing a large number of IFN-stimulated gene (ISG) proteins, several of which have been shown to have specific antiviral functions. Parainfluenza virus type 3 (PIV3) is major pathogen of children, and no reliable vaccine or specific antiviral against it currently exists. In this article, we report several ISG proteins that strongly inhibit PIV3 growth, the use of which may allow a better antiviral regimen targeting PIV3. Copyright © 2016, American Society for Microbiology

  9. Lyssavirus Detection and Typing Using Pyrosequencing▿#‖

    Science.gov (United States)

    De Benedictis, Paola; De Battisti, Cristian; Dacheux, Laurent; Marciano, Sabrina; Ormelli, Silvia; Salomoni, Angela; Caenazzo, Silvia Tiozzo; Lepelletier, Anthony; Bourhy, Hervé; Capua, Ilaria; Cattoli, Giovanni

    2011-01-01

    Rabies is a fatal zoonosis caused by a nonsegmented negative-strand RNA virus, namely, rabies virus (RABV). Apart from RABV, at least 10 additional species are known as rabies-related lyssaviruses (RRVs), and some of them are responsible for occasional spillovers into humans. More lyssaviruses have also been detected recently in different bat ecosystems, thanks to the application of molecular diagnostic methods. Due to the variety of the members of the genus Lyssavirus, there is the necessity to develop a reliable molecular assay for rabies diagnosis able to detect and differentiate among the existing rabies and rabies-related viruses. In the present study, a pyrosequencing protocol targeting the 3′ terminus of the nucleoprotein (N) gene was applied for the rapid characterization of lyssaviruses. Correct identification of species was achieved for each sample tested. Results from the pyrosequencing assay were also confirmed by those obtained using the Sanger sequencing method. A pan-lyssavirus one-step reverse transcription (RT)-PCR was developed within the framework of the pyrosequencing procedure. The sensitivity (Se) of the one-step RT-PCR assay was determined by using in vitro-transcribed RNA and serial dilutions of titrated viruses. The assay demonstrated high analytical and relative specificity (Sp) (98.94%) and sensitivity (99.71%). To date, this is the first case in which pyrosequencing has been applied for lyssavirus identification using a cheaper diagnostic approach than the one for all the other protocols for rapid typing that we are acquainted with. Results from this study indicate that this procedure is suitable for lyssavirus detection in samples of both human and animal origin. PMID:21389152

  10. Alternative RNA splicing and cancer

    Science.gov (United States)

    Liu, Sali; Cheng, Chonghui

    2015-01-01

    Alternative splicing of pre-messenger RNA (mRNA) is a fundamental mechanism by which a gene can give rise to multiple distinct mRNA transcripts, yielding protein isoforms with different, even opposing, functions. With the recognition that alternative splicing occurs in nearly all human genes, its relationship with cancer-associated pathways has emerged as a rapidly growing field. In this review, we summarize recent findings that have implicated the critical role of alternative splicing in cancer and discuss current understandings of the mechanisms underlying dysregulated alternative splicing in cancer cells. PMID:23765697

  11. The ViennaRNA web services.

    Science.gov (United States)

    Gruber, Andreas R; Bernhart, Stephan H; Lorenz, Ronny

    2015-01-01

    The ViennaRNA package is a widely used collection of programs for thermodynamic RNA secondary structure prediction. Over the years, many additional tools have been developed building on the core programs of the package to also address issues related to noncoding RNA detection, RNA folding kinetics, or efficient sequence design considering RNA-RNA hybridizations. The ViennaRNA web services provide easy and user-friendly web access to these tools. This chapter describes how to use this online platform to perform tasks such as prediction of minimum free energy structures, prediction of RNA-RNA hybrids, or noncoding RNA detection. The ViennaRNA web services can be used free of charge and can be accessed via http://rna.tbi.univie.ac.at.

  12. Rapid Generation of MicroRNA Sponges for MicroRNA Inhibition

    NARCIS (Netherlands)

    Kluiver, Joost; Gibcus, Johan H.; Hettinga, Chris; Adema, Annelies; Richter, Mareike K. S.; Halsema, Nancy; Slezak-Prochazka, Izabella; Ding, Ye; Kroesen, Bart-Jan; van den Berg, Anke

    2012-01-01

    MicroRNA (miRNA) sponges are transcripts with repeated miRNA antisense sequences that can sequester miRNAs from endogenous targets. MiRNA sponges are valuable tools for miRNA loss-of-function studies both in vitro and in vivo. We developed a fast and flexible method to generate miRNA sponges and

  13. Identification of Subtype Specific miRNA-mRNA Functional Regulatory Modules in Matched miRNA-mRNA Expression Data: Multiple Myeloma as a Case

    Directory of Open Access Journals (Sweden)

    Yunpeng Zhang

    2015-01-01

    Full Text Available Identification of miRNA-mRNA modules is an important step to elucidate their combinatorial effect on the pathogenesis and mechanisms underlying complex diseases. Current identification methods primarily are based upon miRNA-target information and matched miRNA and mRNA expression profiles. However, for heterogeneous diseases, the miRNA-mRNA regulatory mechanisms may differ between subtypes, leading to differences in clinical behavior. In order to explore the pathogenesis of each subtype, it is important to identify subtype specific miRNA-mRNA modules. In this study, we integrated the Ping-Pong algorithm and multiobjective genetic algorithm to identify subtype specific miRNA-mRNA functional regulatory modules (MFRMs through integrative analysis of three biological data sets: GO biological processes, miRNA target information, and matched miRNA and mRNA expression data. We applied our method on a heterogeneous disease, multiple myeloma (MM, to identify MM subtype specific MFRMs. The constructed miRNA-mRNA regulatory networks provide modular outlook at subtype specific miRNA-mRNA interactions. Furthermore, clustering analysis demonstrated that heterogeneous MFRMs were able to separate corresponding MM subtypes. These subtype specific MFRMs may aid in the further elucidation of the pathogenesis of each subtype and may serve to guide MM subtype diagnosis and treatment.

  14. Alternate capping mechanisms for transcription of spring viremia of carp virus: evidence for independent mRNA initiation.

    Science.gov (United States)

    Gupta, K C; Roy, P

    1980-01-01

    , ed., Control Processes in Virus Multiplication, Cambridge University Press, Cambridge, 1975; D. H. L. Bishop and M. S. Smith, in D. Nayak, ed., The Molecular Biology of Animal Viruses, Marcel Dekker, New York, 1977; P. Roy and D. H. L. Bishop, J. Virol. 11:487-501, 1973) in which mRNA synthesis is initiated independently; they do not support a model for transcripts being synthesized by plus-strand cleavage (A. K. Banerjee, G. Abraham, and R. J. Colonno, J. Gen. Virol. 34:1-8, 1977; A. K. Banerjee, R. J. Colonno, D. Testa, and M. T. Franze-Fernandez, in B. M. J. Mahy and R. D. Barry, ed., Negative Strand Viruses and the Host Cells, Academic Press, London, 1978).

  15. Predicting and Modeling RNA Architecture

    Science.gov (United States)

    Westhof, Eric; Masquida, Benoît; Jossinet, Fabrice

    2011-01-01

    SUMMARY A general approach for modeling the architecture of large and structured RNA molecules is described. The method exploits the modularity and the hierarchical folding of RNA architecture that is viewed as the assembly of preformed double-stranded helices defined by Watson-Crick base pairs and RNA modules maintained by non-Watson-Crick base pairs. Despite the extensive molecular neutrality observed in RNA structures, specificity in RNA folding is achieved through global constraints like lengths of helices, coaxiality of helical stacks, and structures adopted at the junctions of helices. The Assemble integrated suite of computer tools allows for sequence and structure analysis as well as interactive modeling by homology or ab initio assembly with possibilities for fitting within electronic density maps. The local key role of non-Watson-Crick pairs guides RNA architecture formation and offers metrics for assessing the accuracy of three-dimensional models in a more useful way than usual root mean square deviation (RMSD) values. PMID:20504963

  16. Shielding the messenger (RNA): microRNA-based anticancer therapies

    Science.gov (United States)

    Sotillo, Elena; Thomas-Tikhonenko, Andrei

    2011-01-01

    It has been a decade since scientists realized that microRNAs (miRNAs) are not an oddity invented by worms to regulate gene expression at post-transcriptional levels. Rather, many of these 21–22-nucleotide-short RNAs exist in invertebrates and vertebrates alike and some of them are in fact highly conserved. miRNAs are now recognized as an important class of non-coding small RNAs that inhibit gene expression by targeting mRNA stability and translation. In the last ten years, our knowledge of the miRNAs world was expanding at vertiginous speed, propelled by the development of computational engines for miRNA identification and target prediction, biochemical tools and techniques to modulate miRNA activity, and last but not least, the emergence of miRNA-centric animal models. One important conclusion that has emerged from this effort is that many microRNAs and their cognate targets are strongly implicated in cancer, either as oncogenes or tumor and metastasis suppressors. In this review we will discuss the diverse role that miRNAs play in cancer initiation and progression and also the tools with which miRNA expression could be corrected in vivo. While the idea of targeting microRNAs towards therapeutic ends is getting considerable traction, basic, translational, and clinical research done in the next few years will tell whether this promise is well-founded. PMID:21514318

  17. Chaperoning 5S RNA assembly.

    Science.gov (United States)

    Madru, Clément; Lebaron, Simon; Blaud, Magali; Delbos, Lila; Pipoli, Juliana; Pasmant, Eric; Réty, Stéphane; Leulliot, Nicolas

    2015-07-01

    In eukaryotes, three of the four ribosomal RNAs (rRNAs)—the 5.8S, 18S, and 25S/28S rRNAs—are processed from a single pre-rRNA transcript and assembled into ribosomes. The fourth rRNA, the 5S rRNA, is transcribed by RNA polymerase III and is assembled into the 5S ribonucleoprotein particle (RNP), containing ribosomal proteins Rpl5/uL18 and Rpl11/uL5, prior to its incorporation into preribosomes. In mammals, the 5S RNP is also a central regulator of the homeostasis of the tumor suppressor p53. The nucleolar localization of the 5S RNP and its assembly into preribosomes are performed by a specialized complex composed of Rpf2 and Rrs1 in yeast or Bxdc1 and hRrs1 in humans. Here we report the structural and functional characterization of the Rpf2-Rrs1 complex alone, in complex with the 5S RNA, and within pre-60S ribosomes. We show that the Rpf2-Rrs1 complex contains a specialized 5S RNA E-loop-binding module, contacts the Rpl5 protein, and also contacts the ribosome assembly factor Rsa4 and the 25S RNA. We propose that the Rpf2-Rrs1 complex establishes a network of interactions that guide the incorporation of the 5S RNP in preribosomes in the initial conformation prior to its rotation to form the central protuberance found in the mature large ribosomal subunit. © 2015 Madru et al.; Published by Cold Spring Harbor Laboratory Press.

  18. Differential Regulation of rRNA and tRNA Transcription from the rRNA-tRNA Composite Operon in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Hiraku Takada

    Full Text Available Escherichia coli contains seven rRNA operons, each consisting of the genes for three rRNAs (16S, 23S and 5S rRNA in this order and one or two tRNA genes in the spacer between 16S and 23S rRNA genes and one or two tRNA genes in the 3' proximal region. All of these rRNA and tRNA genes are transcribed from two promoters, P1 and P2, into single large precursors that are afterward processed to individual rRNAs and tRNAs by a set of RNases. In the course of Genomic SELEX screening of promoters recognized by RNA polymerase (RNAP holoenzyme containing RpoD sigma, a strong binding site was identified within 16S rRNA gene in each of all seven rRNA operons. The binding in vitro of RNAP RpoD holoenzyme to an internal promoter, referred to the promoter of riRNA (an internal RNA of the rRNA operon, within each 16S rRNA gene was confirmed by gel shift assay and AFM observation. Using this riRNA promoter within the rrnD operon as a representative, transcription in vitro was detected with use of the purified RpoD holoenzyme, confirming the presence of a constitutive promoter in this region. LacZ reporter assay indicated that this riRNA promoter is functional in vivo. The location of riRNA promoter in vivo as identified using a set of reporter plasmids agrees well with that identified in vitro. Based on transcription profile in vitro and Northern blot analysis in vivo, the majority of transcript initiated from this riRNA promoter was estimated to terminate near the beginning of 23S rRNA gene, indicating that riRNA leads to produce the spacer-coded tRNA. Under starved conditions, transcription of the rRNA operon is markedly repressed to reduce the intracellular level of ribosomes, but the levels of both riRNA and its processed tRNAGlu stayed unaffected, implying that riRNA plays a role in the continued steady-state synthesis of tRNAs from the spacers of rRNA operons. We then propose that the tRNA genes organized within the spacers of rRNA-tRNA composite operons

  19. RegRNA: an integrated web server for identifying regulatory RNA motifs and elements

    OpenAIRE

    Huang, Hsi-Yuan; Chien, Chia-Hung; Jen, Kuan-Hua; Huang, Hsien-Da

    2006-01-01

    Numerous regulatory structural motifs have been identified as playing essential roles in transcriptional and post-transcriptional regulation of gene expression. RegRNA is an integrated web server for identifying the homologs of regulatory RNA motifs and elements against an input mRNA sequence. Both sequence homologs and structural homologs of regulatory RNA motifs can be recognized. The regulatory RNA motifs supported in RegRNA are categorized into several classes: (i) motifs in mRNA 5′-untra...

  20. MicroRNA mimicry blocks pulmonary fibrosis

    NARCIS (Netherlands)

    Montgomery, Rusty L; Yu, Guoying; Latimer, Paul A; Stack, Christianna; Robinson, Kathryn; Dalby, Christina M; Kaminski, Naftali; van Rooij, Eva

    2014-01-01

    Over the last decade, great enthusiasm has evolved for microRNA (miRNA) therapeutics. Part of the excitement stems from the fact that a miRNA often regulates numerous related mRNAs. As such, modulation of a single miRNA allows for parallel regulation of multiple genes involved in a particular

  1. Biochemistry and Function of the RNA Exosomes

    DEFF Research Database (Denmark)

    Lubas, Michal Szymon; Chlebowski, Aleksander; Dziembowski, Andrzej

    2012-01-01

    Discovery of the evolutionary conserved RNA exosome was a milestone in RNA biology. First identified as an activity essential for the processing of ribosomal RNA, the exosome has since proved to be central for RNA processing and degradation in both the nucleus and the cytoplasm of eukaryotic cell...

  2. The crystal structure of tRNA

    Indian Academy of Sciences (India)

    Madhu

    of yeast alanine tRNA by Robert Holley's group at Cornell. University ... decode nonsense codons) with John Smith and Brenner. However, my ... tRNA from 10 g of unfractionated tRNA. ... tRNA crystals were, in fact, protein (Hendrikson et al.

  3. A discontinuous RNA platform mediates RNA virus replication: building an integrated model for RNA-based regulation of viral processes.

    Directory of Open Access Journals (Sweden)

    Baodong Wu

    2009-03-01

    Full Text Available Plus-strand RNA viruses contain RNA elements within their genomes that mediate a variety of fundamental viral processes. The traditional view of these elements is that of local RNA structures. This perspective, however, is changing due to increasing discoveries of functional viral RNA elements that are formed by long-range RNA-RNA interactions, often spanning thousands of nucleotides. The plus-strand RNA genomes of tombusviruses exemplify this concept by possessing different long-range RNA-RNA interactions that regulate both viral translation and transcription. Here we report that a third fundamental tombusvirus process, viral genome replication, requires a long-range RNA-based interaction spanning approximately 3000 nts. In vivo and in vitro analyses suggest that the discontinuous RNA platform formed by the interaction facilitates efficient assembly of the viral RNA replicase. This finding has allowed us to build an integrated model for the role of global RNA structure in regulating the reproduction of a eukaryotic RNA virus, and the insights gained have extended our understanding of the multifunctional nature of viral RNA genomes.

  4. Glia to axon RNA transfer.

    Science.gov (United States)

    Sotelo, José Roberto; Canclini, Lucía; Kun, Alejandra; Sotelo-Silveira, José Roberto; Calliari, Aldo; Cal, Karina; Bresque, Mariana; Dipaolo, Andrés; Farias, Joaquina; Mercer, John A

    2014-03-01

    The existence of RNA in axons has been a matter of dispute for decades. Evidence for RNA and ribosomes has now accumulated to a point at which it is difficult to question, much of the disputes turned to the origin of these axonal RNAs. In this review, we focus on studies addressing the origin of axonal RNAs and ribosomes. The neuronal soma as the source of most axonal RNAs has been demonstrated and is indisputable. However, the surrounding glial cells may be a supplemental source of axonal RNAs, a matter scarcely investigated in the literature. Here, we review the few papers that have demonstrated that glial-to-axon RNA transfer is not only feasible, but likely. We describe this process in both invertebrate axons and vertebrate axons. Schwann cell to axon ribosomes transfer was conclusively demonstrated (Court et al. [2008]: J. Neurosci 28:11024-11029; Court et al. [2011]: Glia 59:1529-1539). However, mRNA transfer still remains to be demonstrated in a conclusive way. The intercellular transport of mRNA has interesting implications, particularly with respect to the integration of glial and axonal function. This evolving field is likely to impact our understanding of the cell biology of the axon in both normal and pathological conditions. Most importantly, if the synthesis of proteins in the axon can be controlled by interacting glia, the possibilities for clinical interventions in injury and neurodegeneration are greatly increased. Copyright © 2013 Wiley Periodicals, Inc.

  5. On topological RNA interaction structures.

    Science.gov (United States)

    Qin, Jing; Reidys, Christian M

    2013-07-01

    Recently a folding algorithm of topological RNA pseudoknot structures was presented in Reidys et al. (2011). This algorithm folds single-stranded γ-structures, that is, RNA structures composed by distinct motifs of bounded topological genus. In this article, we set the theoretical foundations for the folding of the two backbone analogues of γ structures: the RNA γ-interaction structures. These are RNA-RNA interaction structures that are constructed by a finite number of building blocks over two backbones having genus at most γ. Combinatorial properties of γ-interaction structures are of practical interest since they have direct implications for the folding of topological interaction structures. We compute the generating function of γ-interaction structures and show that it is algebraic, which implies that the numbers of interaction structures can be computed recursively. We obtain simple asymptotic formulas for 0- and 1-interaction structures. The simplest class of interaction structures are the 0-interaction structures, which represent the two backbone analogues of secondary structures.

  6. Tapping the RNA world for therapeutics.

    Science.gov (United States)

    Lieberman, Judy

    2018-04-16

    A recent revolution in RNA biology has led to the identification of new RNA classes with unanticipated functions, new types of RNA modifications, an unexpected multiplicity of alternative transcripts and widespread transcription of extragenic regions. This development in basic RNA biology has spawned a corresponding revolution in RNA-based strategies to generate new types of therapeutics. Here, I review RNA-based drug design and discuss barriers to broader applications and possible ways to overcome them. Because they target nucleic acids rather than proteins, RNA-based drugs promise to greatly extend the domain of 'druggable' targets beyond what can be achieved with small molecules and biologics.

  7. RNA-Based Vaccines in Cancer Immunotherapy

    Directory of Open Access Journals (Sweden)

    Megan A. McNamara

    2015-01-01

    Full Text Available RNA vaccines traditionally consist of messenger RNA synthesized by in vitro transcription using a bacteriophage RNA polymerase and template DNA that encodes the antigen(s of interest. Once administered and internalized by host cells, the mRNA transcripts are translated directly in the cytoplasm and then the resulting antigens are presented to antigen presenting cells to stimulate an immune response. Alternatively, dendritic cells can be loaded with either tumor associated antigen mRNA or total tumor RNA and delivered to the host to elicit a specific immune response. In this review, we will explain why RNA vaccines represent an attractive platform for cancer immunotherapy, discuss modifications to RNA structure that have been developed to optimize mRNA vaccine stability and translational efficiency, and describe strategies for nonviral delivery of mRNA vaccines, highlighting key preclinical and clinical data related to cancer immunotherapy.

  8. A Regulatory RNA Inducing Transgenerationally Inherited Phenotypes

    DEFF Research Database (Denmark)

    Jensen, Lea Møller

    . The variation in Arabidopsis enables different regulatory networks and mechanisms to shape the phenotypic characteristics. The thesis describes the identification of regulatory RNA encoded by an enzyme encoding gene. The RNA regulates by inducing transgenerationally inherited phenotypes. The function of the RNA...... is dependent on the genetic background illustrating that polymorphisms are found in either interactors or target genes of the RNA. Furthermore, the RNA provides a mechanistic link between accumulation of glucosinolate and onset of flowering....

  9. Screening of Modified RNA duplexes

    DEFF Research Database (Denmark)

    Schyth, Brian Dall; Bramsen, Jesper Bertram; Kjems, Jørgen

    protection against a fish pathogenic virus. This protection corresponded with an interferon response in the fish. Here we use this fish model to screen siRNAs containing various chemical modifications of the RNA backbone for their antiviral activity, the overall aim being identification of an siRNA form......Because of sequence specific gene targeting activity siRNAs are regarded as promising active compounds in gene medicine. But one serious problem with delivering siRNAs as treatment is the now well-established non-specific activities of some RNA duplexes. Cellular reactions towards double stranded...... RNAs include the 2´-5´ oligoadenylate synthetase system, the protein kinase R, RIG-I and Toll-like receptor activated pathways all resulting in antiviral defence mechanism. We have previously shown that antiviral innate immune reactions against double stranded RNAs could be detected in vivo as partial...

  10. TargetRNA: a tool for predicting targets of small RNA action in bacteria

    OpenAIRE

    Tjaden, Brian

    2008-01-01

    Many small RNA (sRNA) genes in bacteria act as posttranscriptional regulators of target messenger RNAs. Here, we present TargetRNA, a web tool for predicting mRNA targets of sRNA action in bacteria. TargetRNA takes as input a genomic sequence that may correspond to an sRNA gene. TargetRNA then uses a dynamic programming algorithm to search each annotated message in a specified genome for mRNAs that evince basepair-binding potential to the input sRNA sequence. Based on the calculated basepair-...

  11. RNA-dependent RNA polymerases from cowpea mosaic virus-infected cowpea leaves

    NARCIS (Netherlands)

    Dorssers, L.

    1983-01-01

    The aim of the research described in this thesis was the purification and identification of the RNA-dependent RNA polymerase engaged in replicating viral RNA in cowpea mosaic virus (CPMV)- infected cowpea leaves.

    Previously, an RNA-dependent RNA polymerase produced upon infection of

  12. RNA Study Using DNA Nanotechnology.

    Science.gov (United States)

    Tadakuma, Hisashi; Masubuchi, Takeya; Ueda, Takuya

    2016-01-01

    Transcription is one of the fundamental steps of gene expression, where RNA polymerases (RNAPs) bind to their template genes and make RNAs. In addition to RNAP and the template gene, many molecules such as transcription factors are involved. The interaction and the effect of these factors depend on the geometry. Molecular layout of these factors, RNAP and gene is thus important. DNA nanotechnology is a promising technology that allows controlling of the molecular layout in the range of nanometer to micrometer scale with nanometer resolution; thus, it is expected to expand the RNA study beyond the current limit. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Isolation of Microarray-Grade Total RNA, MicroRNA, and DNA from a Single PAXgene Blood RNA Tube

    DEFF Research Database (Denmark)

    Kruhøffer, Mogens; Andersen, Lars Dyrskjøt; Voss, Thorsten

    2007-01-01

    We have developed a procedure for isolation of microRNA and genomic DNA in addition to total RNA from whole blood stabilized in PAXgene Blood RNA tubes. The procedure is based on automatic extraction on a BioRobot MDx and includes isolation of DNA from a fraction of the stabilized blood...... and recovery of small RNA species that are otherwise lost. The procedure presented here is suitable for large-scale experiments and is amenable to further automation. Procured total RNA and DNA was tested using Affymetrix Expression and single-nucleotide polymorphism GeneChips, respectively, and isolated micro......RNA was tested using spotted locked nucleic acid-based microarrays. We conclude that the yield and quality of total RNA, microRNA, and DNA from a single PAXgene blood RNA tube is sufficient for downstream microarray analysis....

  14. microRNA-independent recruitment of Argonaute 1 to nanos mRNA through the Smaug RNA-binding protein.

    Science.gov (United States)

    Pinder, Benjamin D; Smibert, Craig A

    2013-01-01

    Argonaute (Ago) proteins are typically recruited to target messenger RNAs via an associated small RNA such as a microRNA (miRNA). Here, we describe a new mechanism of Ago recruitment through the Drosophila Smaug RNA-binding protein. We show that Smaug interacts with the Ago1 protein, and that Ago1 interacts with and is required for the translational repression of the Smaug target, nanos mRNA. The Ago1/nanos mRNA interaction does not require a miRNA, but it does require Smaug. Taken together, our data suggest a model whereby Smaug directly recruits Ago1 to nanos mRNA in a miRNA-independent manner, thereby repressing translation.

  15. Cyclophilin B stimulates RNA synthesis by the HCV RNA dependent RNA polymerase.

    Science.gov (United States)

    Heck, Julie A; Meng, Xiao; Frick, David N

    2009-04-01

    Cyclophilins are cellular peptidyl isomerases that have been implicated in regulating hepatitis C virus (HCV) replication. Cyclophilin B (CypB) is a target of cyclosporin A (CsA), an immunosuppressive drug recently shown to suppress HCV replication in cell culture. Watashi et al. recently demonstrated that CypB is important for efficient HCV replication, and proposed that it mediates the anti-HCV effects of CsA through an interaction with NS5B [Watashi K, Ishii N, Hijikata M, Inoue D, Murata T, Miyanari Y, et al. Cyclophilin B is a functional regulator of hepatitis C virus RNA polymerase. Mol Cell 2005;19:111-22]. We examined the effects of purified CypB proteins on the enzymatic activity of NS5B. Recombinant CypB purified from insect cells directly stimulated NS5B-catalyzed RNA synthesis. CypB increased RNA synthesis by NS5B derived from genotype 1a, 1b, and 2a HCV strains. Stimulation appears to arise from an increase in productive RNA binding. NS5B residue Pro540, a previously proposed target of CypB peptidyl-prolyl isomerase activity, is not required for stimulation of RNA synthesis.

  16. Role of CBCA in RNA biogenesis

    DEFF Research Database (Denmark)

    Iasillo, Claudia

    RNA transcription and RNA processing are key steps in eukaryotic gene expression, which includes, therefore, RNA synthesis by RNA polymerase enzymes and a range of modifications of the pre-mRNA before the transcript can leave the nucleus and reach the cytoplasm for translation. Interestingly......, a large body of evidence suggests that these RNA processing events occur often already during transcription. One of these modifications, the co-transcriptional 5’ end capping of a nascent RNA, is occurring specifically during RNA polymerase II (RNAPII) transcription. The 5’ cap exerts its role via...... the nuclear Cap Binding Complex (CBC). This thesis focuses on the protein ARS2, which binds the CBC to form the CBCA complex. CBCA can further associate with different proteins playing different roles in RNA metabolism. For example, CBCA binds the Nuclear Exosome Targeting Complex (NEXT), which...

  17. Hydration dependent dynamics in RNA

    International Nuclear Information System (INIS)

    Olsen, Greg L.; Bardaro, Michael F.; Echodu, Dorothy C.; Drobny, Gary P.; Varani, Gabriele

    2009-01-01

    The essential role played by local and collective motions in RNA function has led to a growing interest in the characterization of RNA dynamics. Recent investigations have revealed that even relatively simple RNAs experience complex motions over multiple time scales covering the entire ms-ps motional range. In this work, we use deuterium solid-state NMR to systematically investigate motions in HIV-1 TAR RNA as a function of hydration. We probe dynamics at three uridine residues in different structural environments ranging from helical to completely unrestrained. We observe distinct and substantial changes in 2 H solid-state relaxation times and lineshapes at each site as hydration levels increase. By comparing solid-state and solution state 13 C relaxation measurements, we establish that ns-μs motions that may be indicative of collective dynamics suddenly arise in the RNA as hydration reaches a critical point coincident with the onset of bulk hydration. Beyond that point, we observe smaller changes in relaxation rates and lineshapes in these highly hydrated solid samples, compared to the dramatic activation of motion occurring at moderate hydration

  18. RNA Editing in Plant Mitochondria

    Science.gov (United States)

    Hiesel, Rudolf; Wissinger, Bernd; Schuster, Wolfgang; Brennicke, Axel

    1989-12-01

    Comparative sequence analysis of genomic and complementary DNA clones from several mitochondrial genes in the higher plant Oenothera revealed nucleotide sequence divergences between the genomic and the messenger RNA-derived sequences. These sequence alterations could be most easily explained by specific post-transcriptional nucleotide modifications. Most of the nucleotide exchanges in coding regions lead to altered codons in the mRNA that specify amino acids better conserved in evolution than those encoded by the genomic DNA. Several instances show that the genomic arginine codon CGG is edited in the mRNA to the tryptophan codon TGG in amino acid positions that are highly conserved as tryptophan in the homologous proteins of other species. This editing suggests that the standard genetic code is used in plant mitochondria and resolves the frequent coincidence of CGG codons and tryptophan in different plant species. The apparently frequent and non-species-specific equivalency of CGG and TGG codons in particular suggests that RNA editing is a common feature of all higher plant mitochondria.

  19. Nucleocapsid-Independent Specific Viral RNA Packaging via Viral Envelope Protein and Viral RNA Signal

    OpenAIRE

    Narayanan, Krishna; Chen, Chun-Jen; Maeda, Junko; Makino, Shinji

    2003-01-01

    For any of the enveloped RNA viruses studied to date, recognition of a specific RNA packaging signal by the virus's nucleocapsid (N) protein is the first step described in the process of viral RNA packaging. In the murine coronavirus a selective interaction between the viral transmembrane envelope protein M and the viral ribonucleoprotein complex, composed of N protein and viral RNA containing a short cis-acting RNA element, the packaging signal, determines the selective RNA packaging into vi...

  20. Modular arrangement of regulatory RNA elements.

    Science.gov (United States)

    Roßmanith, Johanna; Narberhaus, Franz

    2017-03-04

    Due to their simple architecture and control mechanism, regulatory RNA modules are attractive building blocks in synthetic biology. This is especially true for riboswitches, which are natural ligand-binding regulators of gene expression. The discovery of various tandem riboswitches inspired the design of combined RNA modules with activities not yet found in nature. Riboswitches were placed in tandem or in combination with a ribozyme or temperature-responsive RNA thermometer resulting in new functionalities. Here, we compare natural examples of tandem riboswitches with recently designed artificial RNA regulators suggesting substantial modularity of regulatory RNA elements. Challenges associated with modular RNA design are discussed.

  1. MicroRNA Delivery for Regenerative Medicine

    OpenAIRE

    Peng, Bo; Chen, Yongming; Leong, Kam W.

    2015-01-01

    MicroRNA (miRNA) directs post-transcriptional regulation of a network of genes by targeting mRNA. Although relatively recent in development, many miRNAs direct differentiation of various stem cells including induced pluripotent stem cells (iPSCs), a major player in regenerative medicine. An effective and safe delivery of miRNA holds the key to translating miRNA technologies. Both viral and nonviral delivery systems have seen success in miRNA delivery, and each approach possesses advantages an...

  2. iDoRNA: An Interacting Domain-based Tool for Designing RNA-RNA Interaction Systems

    Directory of Open Access Journals (Sweden)

    Jittrawan Thaiprasit

    2016-03-01

    Full Text Available RNA-RNA interactions play a crucial role in gene regulation in living organisms. They have gained increasing interest in the field of synthetic biology because of their potential applications in medicine and biotechnology. However, few novel regulators based on RNA-RNA interactions with desired structures and functions have been developed due to the challenges of developing design tools. Recently, we proposed a novel tool, called iDoDe, for designing RNA-RNA interacting sequences by first decomposing RNA structures into interacting domains and then designing each domain using a stochastic algorithm. However, iDoDe did not provide an optimal solution because it still lacks a mechanism to optimize the design. In this work, we have further developed the tool by incorporating a genetic algorithm (GA to find an RNA solution with maximized structural similarity and minimized hybridized RNA energy, and renamed the tool iDoRNA. A set of suitable parameters for the genetic algorithm were determined and found to be a weighting factor of 0.7, a crossover rate of 0.9, a mutation rate of 0.1, and the number of individuals per population set to 8. We demonstrated the performance of iDoRNA in comparison with iDoDe by using six RNA-RNA interaction models. It was found that iDoRNA could efficiently generate all models of interacting RNAs with far more accuracy and required far less computational time than iDoDe. Moreover, we compared the design performance of our tool against existing design tools using forty-four RNA-RNA interaction models. The results showed that the performance of iDoRNA is better than RiboMaker when considering the ensemble defect, the fitness score and computation time usage. However, it appears that iDoRNA is outperformed by NUPACK and RNAiFold 2.0 when considering the ensemble defect. Nevertheless, iDoRNA can still be an useful alternative tool for designing novel RNA-RNA interactions in synthetic biology research. The source code of iDoRNA

  3. Comprehensive characterization of lncRNA-mRNA related ceRNA network across 12 major cancers

    Science.gov (United States)

    Feng, Li; Li, Feng; Sun, Zeguo; Wu, Tan; Shi, Xinrui; Li, Jing; Li, Xia

    2016-01-01

    Recent studies indicate that long noncoding RNAs (lncRNAs) can act as competing endogenous RNAs (ceRNAs) to indirectly regulate mRNAs through shared microRNAs, which represents a novel layer of RNA crosstalk and plays critical roles in the development of tumor. However, the global regulation landscape and characterization of these lncRNA related ceRNA crosstalk in cancers is still largely unknown. Here, we systematically characterized the lncRNA related ceRNA interactions across 12 major cancers and the normal physiological states by integrating multidimensional molecule profiles of more than 5000 samples. Our study suggest the large difference of ceRNA regulation between normal and tumor states and the higher similarity across similar tissue origin of tumors. The ceRNA related molecules have more conserved features in tumor networks and they play critical roles in both the normal and tumorigenesis processes. Besides, lncRNAs in the pan-cancer ceRNA network may be potential biomarkers of tumor. By exploring hub lncRNAs, we found that these conserved key lncRNAs dominate variable tumor hallmark processes across pan-cancers. Network dynamic analysis highlights the critical roles of ceRNA regulation in tumorigenesis. By analyzing conserved ceRNA interactions, we found that miRNA mediate ceRNA regulation showed different patterns across pan-cancer; while analyzing the cancer specific ceRNA interactions reveal that lncRNAs synergistically regulated tumor driver genes of cancer hallmarks. Finally, we found that ceRNA modules have the potential to predict patient survival. Overall, our study systematically dissected the lncRNA related ceRNA networks in pan-cancer that shed new light on understanding the molecular mechanism of tumorigenesis. PMID:27580177

  4. Application of Live-Cell RNA Imaging Techniques to the Study of Retroviral RNA Trafficking

    Directory of Open Access Journals (Sweden)

    Darrin V. Bann

    2012-06-01

    Full Text Available Retroviruses produce full-length RNA that serves both as a genomic RNA (gRNA, which is encapsidated into virus particles, and as an mRNA, which directs the synthesis of viral structural proteins. However, we are only beginning to understand the cellular and viral factors that influence trafficking of retroviral RNA and the selection of the RNA for encapsidation or translation. Live cell imaging studies of retroviral RNA trafficking have provided important insight into many aspects of the retrovirus life cycle including transcription dynamics, nuclear export of viral RNA, translational regulation, membrane targeting, and condensation of the gRNA during virion assembly. Here, we review cutting-edge techniques to visualize single RNA molecules in live cells and discuss the application of these systems to studying retroviral RNA trafficking.

  5. How the RNA isolation method can affect microRNA microarray results

    DEFF Research Database (Denmark)

    Podolska, Agnieszka; Kaczkowski, Bogumil; Litman, Thomas

    2011-01-01

    RNA microarray analysis on porcine brain tissue. One method is a phenol-guanidine isothiocyanate-based procedure that permits isolation of total RNA. The second method, miRVana™ microRNA isolation, is column based and recovers the small RNA fraction alone. We found that microarray analyses give different results...... that depend on the RNA fraction used, in particular because some microRNAs appear very sensitive to the RNA isolation method. We conclude that precautions need to be taken when comparing microarray studies based on RNA isolated with different methods.......The quality of RNA is crucial in gene expression experiments. RNA degradation interferes in the measurement of gene expression, and in this context, microRNA quantification can lead to an incorrect estimation. In the present study, two different RNA isolation methods were used to perform micro...

  6. Topology and prediction of RNA pseudoknots

    DEFF Research Database (Denmark)

    Reidys, Christian; Huang, Fenix; Andersen, Jørgen Ellegaard

    2011-01-01

    Motivation: Several dynamic programming algorithms for predicting RNA structures with pseudoknots have been proposed that differ dramatically from one another in the classes of structures considered. Results: Here, we use the natural topological classification of RNA structures in terms...

  7. RNA Structural Alignments, Part I

    DEFF Research Database (Denmark)

    Havgaard, Jakob Hull; Gorodkin, Jan

    2014-01-01

    Simultaneous alignment and secondary structure prediction of RNA sequences is often referred to as "RNA structural alignment." A class of the methods for structural alignment is based on the principles proposed by Sankoff more than 25 years ago. The Sankoff algorithm simultaneously folds and aligns...... is so high that it took more than a decade before the first implementation of a Sankoff style algorithm was published. However, with the faster computers available today and the improved heuristics used in the implementations the Sankoff-based methods have become practical. This chapter describes...... the methods based on the Sankoff algorithm. All the practical implementations of the algorithm use heuristics to make them run in reasonable time and memory. These heuristics are also described in this chapter....

  8. Fatgraph models of RNA structure

    Directory of Open Access Journals (Sweden)

    Huang Fenix

    2017-01-01

    Full Text Available In this review paper we discuss fatgraphs as a conceptual framework for RNA structures. We discuss various notions of coarse-grained RNA structures and relate them to fatgraphs.We motivate and discuss the main intuition behind the fatgraph model and showcase its applicability to canonical as well as noncanonical base pairs. Recent discoveries regarding novel recursions of pseudoknotted (pk configurations as well as their translation into context-free grammars for pk-structures are discussed. This is shown to allow for extending the concept of partition functions of sequences w.r.t. a fixed structure having non-crossing arcs to pk-structures. We discuss minimum free energy folding of pk-structures and combine these above results outlining how to obtain an inverse folding algorithm for PK structures.

  9. RNA

    African Journals Online (AJOL)

    SARAH

    30 nov. 2013 ... Keywords: FMNR, mode of management, re-greening, leadership, evolutionary trend. INTRODUCTION .... régénération : L'évolution de la densité des ligneux entre. 2005 et 2012 ..... la production et la qualité fourragères de la.

  10. Nonradioactive RNA mobility shift with chemiluminescent detection ...

    African Journals Online (AJOL)

    hesham

    RNA mobility shift is one among many procedures used to study RNA-protein interaction. Yet, there are some limitations for the radioactive RNA mobility shift including; 1) the risk of using radiolabeled nucleotides, 2) the long time to get the results; this could range from days to weeks, and 3) its high cost as compared to ...

  11. Optimization of chemiluminescent detection of mitochondrial RNA ...

    African Journals Online (AJOL)

    RNA mobility shift is one among many procedures used to study RNA-protein interaction. Yet, there are some limitations for the radioactive RNA mobility shift including; 1) the risk of using radiolabeled nucleotides, 2) the long time to get the results; this could range from days to weeks, and 3) its high cost as compared to ...

  12. RNA polymerase activity of Ustilago maydis virus

    Energy Technology Data Exchange (ETDEWEB)

    Yie, S.W.

    1986-01-01

    Ustilago maydis virus has an RNA polymerase enzyme which is associated with virion capsids. In the presence of Mg/sup 2 +/ ion and ribonucleotide triphosphate, the enzyme catalyzes the in vitro synthesis of mRNA by using dsRNA as a template. The products of the UmV RNA polymerase were both ssRNA and dsRNA. The dsRNA was determined by characteristic mobilities in gel electrophoresis, lack of sensitivity to RNase, and specific hybridization tests. The ssRNAs were identified by elution from a CF-11 column and by their RNase sensitivity. On the basis of the size of ssRNAs, it was concluded that partial transcripts were produced from H dsRNA segments, and full length transcripts were produced from M and L dsRNA segments. The following observations indicates that transcription occurs by strand displacement; (1) Only the positive strand of M2 dsRNA was labeled by the in vitro reaction. (2) The M2 dsRNA which had been labeled with /sup 32/''P-UTP in vitro could be chased from dsRNA with unlabeled UTP. The transcription products of three UmV strains were compared, and the overall pattern of transcription was very similar among them.

  13. Analysis of RNA metabolism in fission yeast

    DEFF Research Database (Denmark)

    Wise, Jo Ann; Nielsen, Olaf

    2017-01-01

    Here we focus on the biogenesis and function of messenger RNA (mRNA) in fission yeast cells. Following a general introduction that also briefly touches on other classes of RNA, we provide an overview of methods used to analyze mRNAs throughout their life cycles....

  14. A Specific Hepatic Transfer RNA for Phosphoserine*

    Science.gov (United States)

    Mäenpää, Pekka H.; Bernfield, Merton R.

    1970-01-01

    Radioactive O-phosphoryl-L-serine was detected after alkaline deacylation of rat and rooster liver [3H]seryl-tRNA acylated in vitro with homologous synthetases. Ribonuclease treatment of this tRNA yielded a compound with the properties of phosphoseryl-adenosine. Benzoylated DEAE-cellulose chromatography of seryl-tRNA yielded four distinct peaks, only one of which contained phosphoserine. A unique fraction for phosphoserine was also found on chromatography of nonacylated tRNA. In ribosome binding studies, this fraction responded very slightly with poly(U,C), but not with any of the known serine trinucleotide codons. Substantial incorporation of [3H]-serine into protein from this tRNA species was observed in an aminoacyl-tRNA dependent polysomal system derived from chick oviducts. No phosphoserine was found in Escherichia coli or yeast seryl-tRNA acylated with homologous enzymes, nor in E. coli seryl-tRNA acylated with liver synthetase. In the absence of tRNA, free phosphoserine was not formed in reaction mixtures, which suggests that phosphoseryl-tRNA arises by phosphorylation of the unique seryl-tRNA species. These results demonstrate a discrete tRNASer species in rat and rooster liver containing phosphoserine and suggest that this tRNA is involved in ribosomal polypeptide synthesis. PMID:4943179

  15. Cisplatin Targeting of Bacterial Ribosomal RNA Hairpins

    Directory of Open Access Journals (Sweden)

    Gayani N. P. Dedduwa-Mudalige

    2015-09-01

    Full Text Available Cisplatin is a clinically important chemotherapeutic agent known to target purine bases in nucleic acids. In addition to major deoxyribonucleic acid (DNA intrastrand cross-links, cisplatin also forms stable adducts with many types of ribonucleic acid (RNA including siRNA, spliceosomal RNAs, tRNA, and rRNA. All of these RNAs play vital roles in the cell, such as catalysis of protein synthesis by rRNA, and therefore serve as potential drug targets. This work focused on platination of two highly conserved RNA hairpins from E. coli ribosomes, namely pseudouridine-modified helix 69 from 23S rRNA and the 790 loop of helix 24 from 16S rRNA. RNase T1 probing, MALDI mass spectrometry, and dimethyl sulfate mapping revealed platination at GpG sites. Chemical probing results also showed platination-induced RNA structural changes. These findings reveal solvent and structural accessibility of sites within bacterial RNA secondary structures that are functionally significant and therefore viable targets for cisplatin as well as other classes of small molecules. Identifying target preferences at the nucleotide level, as well as determining cisplatin-induced RNA conformational changes, is important for the design of more potent drug molecules. Furthermore, the knowledge gained through studies of RNA-targeting by cisplatin is applicable to a broad range of organisms from bacteria to human.

  16. Supplementary data: Materials and methods RNA expression ...

    Indian Academy of Sciences (India)

    ritt8

    Supplementary data: Materials and methods. RNA expression analysis. Freshly collected tissue was taken in TRIzol reagent for total RNA isolation according to the manufacturer's protocol. The cDNA synthesis was carried out in 1 μg total RNA using Random hexamer (Invitrogen, Carlsbad, USA) and Superscript III ...

  17. Regulatory RNAs derived from transfer RNA?

    Science.gov (United States)

    Pederson, Thoru

    2010-10-01

    Four recent studies suggest that cleavages of transfer RNAs generate products with microRNA-like features, with some evidence of function. If their regulatory functions were to be confirmed, these newly revealed RNAs would add to the expanding repertoire of small noncoding RNAs and would also provide new perspectives on the coevolution of transfer RNA and messenger RNA.

  18. Regulatory BC1 RNA in Cognitive Control

    Science.gov (United States)

    Iacoangeli, Anna; Dosunmu, Aderemi; Eom, Taesun; Stefanov, Dimitre G.; Tiedge, Henri

    2017-01-01

    Dendritic regulatory BC1 RNA is a non-protein-coding (npc) RNA that operates in the translational control of gene expression. The absence of BC1 RNA in BC1 knockout (KO) animals causes translational dysregulation that entails neuronal phenotypic alterations including prolonged epileptiform discharges, audiogenic seizure activity in vivo, and…

  19. Primer-dependent and primer-independent initiation of double stranded RNA synthesis by purified arabidopsis RNA-dependent RNA polymerases RDR2 and RDR6

    DEFF Research Database (Denmark)

    Devert, Anthony; Fabre, Nicolas; Floris, Maina Huguette Joséphine

    2015-01-01

    ) targeted by RNA silencing. The dsRNA is subsequently cleaved by the ribonuclease DICER-like into secondary small interfering RNAs (siRNAs) that reinforce and/or maintain the silenced state of the target RNA. Models of RNA silencing propose that RDRs could use primer-independent and primer......Cellular RNA-dependent RNA polymerases (RDRs) are fundamental components of RNA silencing in plants and many other eukaryotes. In Arabidopsis thaliana genetic studies have demonstrated that RDR2 and RDR6 are involved in the synthesis of double stranded RNA (dsRNA) from single stranded RNA (ssRNA......-dependent initiation to generate dsRNA from a transcript targeted by primary siRNA or microRNA (miRNA). However, the biochemical activities of RDR proteins are still partly understood. Here, we obtained active recombinant RDR2 and RDR6 in a purified form. We demonstrate that RDR2 and RDR6 have primer...

  20. Effective Anti-miRNA Oligonucleotides Show High Releasing Rate of MicroRNA from RNA-Induced Silencing Complex.

    Science.gov (United States)

    Ariyoshi, Jumpei; Matsuyama, Yohei; Kobori, Akio; Murakami, Akira; Sugiyama, Hiroshi; Yamayoshi, Asako

    2017-10-01

    MicroRNAs (miRNAs) regulate gene expression by forming RNA-induced silencing complexes (RISCs) and have been considered as promising therapeutic targets. MiRNA is an essential component of RISC for the modulation of gene expression. Therefore, the release of miRNA from RISC is considered as an effective method for the inhibition of miRNA functions. In our previous study, we reported that anti-miRNA oligonucleotides (AMOs), which are composed of the 2'-O-methyl (2'-OMe) RNA, could induce the release of miRNA from RISC. However, the mechanisms underlying the miRNA-releasing effects of chemically modified AMOs, which are conventionally used as anti-cancer drugs, are still unclear. In this study, we investigated the relationship between the miRNA releasing rate from RISC and the inhibitory effect on RISC activity (IC 50 ) using conventional chemically modified AMOs. We demonstrated that the miRNA-releasing effects of AMOs are directly proportional to the IC 50 values, and AMOs, which have an ability to promote the release of miRNA from RISC, can effectively inhibit RISC activity in living cells.

  1. Diverging affinity of tospovirus RNA silencing suppressor proteins, NSs, for various RNA duplex molecules.

    Science.gov (United States)

    Schnettler, Esther; Hemmes, Hans; Huismann, Rik; Goldbach, Rob; Prins, Marcel; Kormelink, Richard

    2010-11-01

    The tospovirus NSs protein was previously shown to suppress the antiviral RNA silencing mechanism in plants. Here the biochemical analysis of NSs proteins from different tospoviruses, using purified NSs or NSs containing cell extracts, is described. The results showed that all tospoviral NSs proteins analyzed exhibited affinity to small double-stranded RNA molecules, i.e., small interfering RNAs (siRNAs) and micro-RNA (miRNA)/miRNA* duplexes. Interestingly, the NSs proteins from tomato spotted wilt virus (TSWV), impatiens necrotic spot virus (INSV), and groundnut ringspot virus (GRSV) also showed affinity to long double-stranded RNA (dsRNA), whereas tomato yellow ring virus (TYRV) NSs did not. The TSWV NSs protein was shown to be capable of inhibiting Dicer-mediated cleavage of long dsRNA in vitro. In addition, it suppressed the accumulation of green fluorescent protein (GFP)-specific siRNAs during coinfiltration with an inverted-repeat-GFP RNA construct in Nicotiana benthamiana. In vivo interference of TSWV NSs in the miRNA pathway was shown by suppression of an enhanced GFP (eGFP) miRNA sensor construct. The ability to stabilize miRNA/miRNA* by different tospovirus NSs proteins in vivo was demonstrated by increased accumulation and detection of both miRNA171c and miRNA171c* in tospovirus-infected N. benthamiana. All together, these data suggest that tospoviruses interfere in the RNA silencing pathway by sequestering siRNA and miRNA/miRNA* molecules before they are uploaded into their respective RNA-induced silencing complexes. The observed affinity to long dsRNA for only a subset of the tospoviruses studied is discussed in light of evolutional divergence and their ancestral relation to the animal-infecting members of the Bunyaviridae.

  2. Targeted CRISPR disruption reveals a role for RNase MRP RNA in human preribosomal RNA processing.

    Science.gov (United States)

    Goldfarb, Katherine C; Cech, Thomas R

    2017-01-01

    MRP RNA is an abundant, essential noncoding RNA whose functions have been proposed in yeast but are incompletely understood in humans. Mutations in the genomic locus for MRP RNA cause pleiotropic human diseases, including cartilage hair hypoplasia (CHH). Here we applied CRISPR-Cas9 genome editing to disrupt the endogenous human MRP RNA locus, thereby attaining what has eluded RNAi and RNase H experiments: elimination of MRP RNA in the majority of cells. The resulting accumulation of ribosomal RNA (rRNA) precursor-analyzed by RNA fluorescent in situ hybridization (FISH), Northern blots, and RNA sequencing-implicates MRP RNA in pre-rRNA processing. Amelioration of pre-rRNA imbalance is achieved through rescue of MRP RNA levels by ectopic expression. Furthermore, affinity-purified MRP ribonucleoprotein (RNP) from HeLa cells cleaves the human pre-rRNA in vitro at at least one site used in cells, while RNP isolated from cells with CRISPR-edited MRP loci loses this activity, and ectopic MRP RNA expression restores cleavage activity. Thus, a role for RNase MRP in human pre-rRNA processing is established. As demonstrated here, targeted CRISPR disruption is a valuable tool for functional studies of essential noncoding RNAs that are resistant to RNAi and RNase H-based degradation. © 2017 Goldfarb and Cech; Published by Cold Spring Harbor Laboratory Press.

  3. The early history of tRNA recognition by aminoacyl-tRNA synthetases

    Indian Academy of Sciences (India)

    Madhu

    2006-10-04

    Oct 4, 2006 ... Discovery of aminoacyl-tRNA synthetases and importance ... The pioneering work of Fritz Lipmann on the high-energy ... the peculiar structural and functional relationships tRNAs ... a bulk of only 20 families of tRNA molecules in contrast ...... balance of tRNA and aminoacyl-tRNA synthetase; Science 242.

  4. Cooperation of an RNA Packaging Signal and a Viral Envelope Protein in Coronavirus RNA Packaging

    OpenAIRE

    Narayanan, Krishna; Makino, Shinji

    2001-01-01

    Murine coronavirus mouse hepatitis virus (MHV) produces a genome-length mRNA, mRNA 1, and six or seven species of subgenomic mRNAs in infected cells. Among these mRNAs, only mRNA 1 is efficiently packaged into MHV particles. MHV N protein binds to all MHV mRNAs, whereas envelope M protein interacts only with mRNA 1. This M protein-mRNA 1 interaction most probably determines the selective packaging of mRNA 1 into MHV particles. A short cis-acting MHV RNA packaging signal is necessary and suffi...

  5. Sequence analysis of RNase MRP RNA reveals its origination from eukaryotic RNase P RNA

    Science.gov (United States)

    Zhu, Yanglong; Stribinskis, Vilius; Ramos, Kenneth S.; Li, Yong

    2006-01-01

    RNase MRP is a eukaryote-specific endoribonuclease that generates RNA primers for mitochondrial DNA replication and processes precursor rRNA. RNase P is a ubiquitous endoribonuclease that cleaves precursor tRNA transcripts to produce their mature 5′ termini. We found extensive sequence homology of catalytic domains and specificity domains between their RNA subunits in many organisms. In Candida glabrata, the internal loop of helix P3 is 100% conserved between MRP and P RNAs. The helix P8 of MRP RNA from microsporidia Encephalitozoon cuniculi is identical to that of P RNA. Sequence homology can be widely spread over the whole molecule of MRP RNA and P RNA, such as those from Dictyostelium discoideum. These conserved nucleotides between the MRP and P RNAs strongly support the hypothesis that the MRP RNA is derived from the P RNA molecule in early eukaryote evolution. PMID:16540690

  6. RNA polymerase II mediated transcription from the polymerase III promoters in short hairpin RNA expression vector

    International Nuclear Information System (INIS)

    Rumi, Mohammad; Ishihara, Shunji; Aziz, Monowar; Kazumori, Hideaki; Ishimura, Norihisa; Yuki, Takafumi; Kadota, Chikara; Kadowaki, Yasunori; Kinoshita, Yoshikazu

    2006-01-01

    RNA polymerase III promoters of human ribonuclease P RNA component H1, human U6, and mouse U6 small nuclear RNA genes are commonly used in short hairpin RNA (shRNA) expression vectors due their precise initiation and termination sites. During transient transfection of shRNA vectors, we observed that H1 or U6 promoters also express longer transcripts enough to express several reporter genes including firefly luciferase, green fluorescent protein EGFP, and red fluorescent protein JRed. Expression of such longer transcripts was augmented by upstream RNA polymerase II enhancers and completely inhibited by downstream polyA signal sequences. Moreover, the transcription of firefly luciferase from human H1 promoter was sensitive to RNA polymerase II inhibitor α-amanitin. Our findings suggest that commonly used polymerase III promoters in shRNA vectors are also prone to RNA polymerase II mediated transcription, which may have negative impacts on their targeted use

  7. Using RNA Interference to Study Protein Function

    OpenAIRE

    Curtis, Carol D.; Nardulli, Ann M.

    2009-01-01

    RNA interference can be extremely useful in determining the function of an endogenously-expressed protein in its normal cellular environment. In this chapter, we describe a method that uses small interfering RNA (siRNA) to knock down mRNA and protein expression in cultured cells so that the effect of a putative regulatory protein on gene expression can be delineated. Methods of assessing the effectiveness of the siRNA procedure using real time quantitative PCR and Western analysis are also in...

  8. Analysis of extracellular RNA by digital PCR

    Directory of Open Access Journals (Sweden)

    Kenji eTakahashi

    2014-06-01

    Full Text Available The transfer of extracellular RNA is emerging as an important mechanism for intracellular communication. The ability for the transfer of functionally active RNA molecules from one cell to another within vesicles such as exosomes enables a cell to modulate cellular signaling and biological processes within recipient cells. The study of extracellular RNA requires sensitive methods for the detection of these molecules. In this methods article, we will describe protocols for the detection of such extracellular RNA using sensitive detection technologies such as digital PCR. These protocols should be valuable to researchers interested in the role and contribution of extracellular RNA to tumor cell biology.

  9. Characteristics and Prediction of RNA Structure

    Directory of Open Access Journals (Sweden)

    Hengwu Li

    2014-01-01

    Full Text Available RNA secondary structures with pseudoknots are often predicted by minimizing free energy, which is NP-hard. Most RNAs fold during transcription from DNA into RNA through a hierarchical pathway wherein secondary structures form prior to tertiary structures. Real RNA secondary structures often have local instead of global optimization because of kinetic reasons. The performance of RNA structure prediction may be improved by considering dynamic and hierarchical folding mechanisms. This study is a novel report on RNA folding that accords with the golden mean characteristic based on the statistical analysis of the real RNA secondary structures of all 480 sequences from RNA STRAND, which are validated by NMR or X-ray. The length ratios of domains in these sequences are approximately 0.382L, 0.5L, 0.618L, and L, where L is the sequence length. These points are just the important golden sections of sequence. With this characteristic, an algorithm is designed to predict RNA hierarchical structures and simulate RNA folding by dynamically folding RNA structures according to the above golden section points. The sensitivity and number of predicted pseudoknots of our algorithm are better than those of the Mfold, HotKnots, McQfold, ProbKnot, and Lhw-Zhu algorithms. Experimental results reflect the folding rules of RNA from a new angle that is close to natural folding.

  10. siRNA and innate immunity.

    Science.gov (United States)

    Robbins, Marjorie; Judge, Adam; MacLachlan, Ian

    2009-06-01

    Canonical small interfering RNA (siRNA) duplexes are potent activators of the mammalian innate immune system. The induction of innate immunity by siRNA is dependent on siRNA structure and sequence, method of delivery, and cell type. Synthetic siRNA in delivery vehicles that facilitate cellular uptake can induce high levels of inflammatory cytokines and interferons after systemic administration in mammals and in primary human blood cell cultures. This activation is predominantly mediated by immune cells, normally via a Toll-like receptor (TLR) pathway. The siRNA sequence dependency of these pathways varies with the type and location of the TLR involved. Alternatively nonimmune cell activation may also occur, typically resulting from siRNA interaction with cytoplasmic RNA sensors such as RIG1. As immune activation by siRNA-based drugs represents an undesirable side effect due to the considerable toxicities associated with excessive cytokine release in humans, understanding and abrogating this activity will be a critical component in the development of safe and effective therapeutics. This review describes the intracellular mechanisms of innate immune activation by siRNA, the design of appropriate sequences and chemical modification approaches, and suitable experimental methods for studying their effects, with a view toward reducing siRNA-mediated off-target effects.

  11. TruSeq Stranded mRNA and Total RNA Sample Preparation Kits

    Science.gov (United States)

    Total RNA-Seq enabled by ribosomal RNA (rRNA) reduction is compatible with formalin-fixed paraffin embedded (FFPE) samples, which contain potentially critical biological information. The family of TruSeq Stranded Total RNA sample preparation kits provides a unique combination of unmatched data quality for both mRNA and whole-transcriptome analyses, robust interrogation of both standard and low-quality samples and workflows compatible with a wide range of study designs.

  12. MysiRNA-designer: a workflow for efficient siRNA design.

    Directory of Open Access Journals (Sweden)

    Mohamed Mysara

    Full Text Available The design of small interfering RNA (siRNA is a multi factorial problem that has gained the attention of many researchers in the area of therapeutic and functional genomics. MysiRNA score was previously introduced that improves the correlation of siRNA activity prediction considering state of the art algorithms. In this paper, a new program, MysiRNA-Designer, is described which integrates several factors in an automated work-flow considering mRNA transcripts variations, siRNA and mRNA target accessibility, and both near-perfect and partial off-target matches. It also features the MysiRNA score, a highly ranked correlated siRNA efficacy prediction score for ranking the designed siRNAs, in addition to top scoring models Biopredsi, DISR, Thermocomposition21 and i-Score, and integrates them in a unique siRNA score-filtration technique. This multi-score filtration layer filters siRNA that passes the 90% thresholds calculated from experimental dataset features. MysiRNA-Designer takes an accession, finds conserved regions among its transcript space, finds accessible regions within the mRNA, designs all possible siRNAs for these regions, filters them based on multi-scores thresholds, and then performs SNP and off-target filtration. These strict selection criteria were tested against human genes in which at least one active siRNA was designed from 95.7% of total genes. In addition, when tested against an experimental dataset, MysiRNA-Designer was found capable of rejecting 98% of the false positive siRNAs, showing superiority over three state of the art siRNA design programs. MysiRNA is a freely accessible (Microsoft Windows based desktop application that can be used to design siRNA with a high accuracy and specificity. We believe that MysiRNA-Designer has the potential to play an important role in this area.

  13. 5S rRNA and ribosome.

    Science.gov (United States)

    Gongadze, G M

    2011-12-01

    5S rRNA is an integral component of the ribosome of all living organisms. It is known that the ribosome without 5S rRNA is functionally inactive. However, the question about the specific role of this RNA in functioning of the translation apparatus is still open. This review presents a brief history of the discovery of 5S rRNA and studies of its origin and localization in the ribosome. The previously expressed hypotheses about the role of this RNA in the functioning of the ribosome are discussed considering the unique location of 5S rRNA in the ribosome and its intermolecular contacts. Based on analysis of the current data on ribosome structure and its functional complexes, the role of 5S rRNA as an intermediary between ribosome functional domains is discussed.

  14. Kin Selection in the RNA World.

    Science.gov (United States)

    Levin, Samuel R; West, Stuart A

    2017-12-05

    Various steps in the RNA world required cooperation. Why did life's first inhabitants, from polymerases to synthetases, cooperate? We develop kin selection models of the RNA world to answer these questions. We develop a very simple model of RNA cooperation and then elaborate it to model three relevant issues in RNA biology: (1) whether cooperative RNAs receive the benefits of cooperation; (2) the scale of competition in RNA populations; and (3) explicit replicator diffusion and survival. We show: (1) that RNAs are likely to express partial cooperation; (2) that RNAs will need mechanisms for overcoming local competition; and (3) in a specific example of RNA cooperation, persistence after replication and offspring diffusion allow for cooperation to overcome competition. More generally, we show how kin selection can unify previously disparate answers to the question of RNA world cooperation.

  15. MicroRNA and cancer

    DEFF Research Database (Denmark)

    Jansson, Martin D; Lund, Anders H

    2012-01-01

    biological phenomena and pathologies. The best characterized non-coding RNA family consists in humans of about 1400 microRNAs for which abundant evidence have demonstrated fundamental importance in normal development, differentiation, growth control and in human diseases such as cancer. In this review, we...... summarize the current knowledge and concepts concerning the involvement of microRNAs in cancer, which have emerged from the study of cell culture and animal model systems, including the regulation of key cancer-related pathways, such as cell cycle control and the DNA damage response. Importantly, micro...

  16. RNA2DMut: a web tool for the design and analysis of RNA structure mutations.

    Science.gov (United States)

    Moss, Walter N

    2018-03-01

    With the widespread application of high-throughput sequencing, novel RNA sequences are being discovered at an astonishing rate. The analysis of function, however, lags behind. In both the cis - and trans -regulatory functions of RNA, secondary structure (2D base-pairing) plays essential regulatory roles. In order to test RNA function, it is essential to be able to design and analyze mutations that can affect structure. This was the motivation for the creation of the RNA2DMut web tool. With RNA2DMut, users can enter in RNA sequences to analyze, constrain mutations to specific residues, or limit changes to purines/pyrimidines. The sequence is analyzed at each base to determine the effect of every possible point mutation on 2D structure. The metrics used in RNA2DMut rely on the calculation of the Boltzmann structure ensemble and do not require a robust 2D model of RNA structure for designing mutations. This tool can facilitate a wide array of uses involving RNA: for example, in designing and evaluating mutants for biological assays, interrogating RNA-protein interactions, identifying key regions to alter in SELEX experiments, and improving RNA folding and crystallization properties for structural biology. Additional tools are available to help users introduce other mutations (e.g., indels and substitutions) and evaluate their effects on RNA structure. Example calculations are shown for five RNAs that require 2D structure for their function: the MALAT1 mascRNA, an influenza virus splicing regulatory motif, the EBER2 viral noncoding RNA, the Xist lncRNA repA region, and human Y RNA 5. RNA2DMut can be accessed at https://rna2dmut.bb.iastate.edu/. © 2018 Moss; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  17. RNA versatility, flexibility, and thermostability for practice in RNA nanotechnology and biomedical applications.

    Science.gov (United States)

    Haque, Farzin; Pi, Fengmei; Zhao, Zhengyi; Gu, Shanqing; Hu, Haibo; Yu, Hang; Guo, Peixuan

    2018-01-01

    In recent years, RNA has attracted widespread attention as a unique biomaterial with distinct biophysical properties for designing sophisticated architectures in the nanometer scale. RNA is much more versatile in structure and function with higher thermodynamic stability compared to its nucleic acid counterpart DNA. Larger RNA molecules can be viewed as a modular structure built from a combination of many 'Lego' building blocks connected via different linker sequences. By exploiting the diversity of RNA motifs and flexibility of structure, varieties of RNA architectures can be fabricated with precise control of shape, size, and stoichiometry. Many structural motifs have been discovered and characterized over the years and the crystal structures of many of these motifs are available for nanoparticle construction. For example, using the flexibility and versatility of RNA structure, RNA triangles, squares, pentagons, and hexagons can be constructed from phi29 pRNA three-way-junction (3WJ) building block. This review will focus on 2D RNA triangles, squares, and hexamers; 3D and 4D structures built from basic RNA building blocks; and their prospective applications in vivo as imaging or therapeutic agents via specific delivery and targeting. Methods for intracellular cloning and expression of RNA molecules and the in vivo assembly of RNA nanoparticles will also be reviewed. WIREs RNA 2018, 9:e1452. doi: 10.1002/wrna.1452 This article is categorized under: RNA Methods > RNA Nanotechnology RNA Structure and Dynamics > RNA Structure, Dynamics and Chemistry RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs. © 2017 Wiley Periodicals, Inc.

  18. Evaluation of microRNA alignment techniques

    Science.gov (United States)

    Kaspi, Antony; El-Osta, Assam

    2016-01-01

    Genomic alignment of small RNA (smRNA) sequences such as microRNAs poses considerable challenges due to their short length (∼21 nucleotides [nt]) as well as the large size and complexity of plant and animal genomes. While several tools have been developed for high-throughput mapping of longer mRNA-seq reads (>30 nt), there are few that are specifically designed for mapping of smRNA reads including microRNAs. The accuracy of these mappers has not been systematically determined in the case of smRNA-seq. In addition, it is unknown whether these aligners accurately map smRNA reads containing sequence errors and polymorphisms. By using simulated read sets, we determine the alignment sensitivity and accuracy of 16 short-read mappers and quantify their robustness to mismatches, indels, and nontemplated nucleotide additions. These were explored in the context of a plant genome (Oryza sativa, ∼500 Mbp) and a mammalian genome (Homo sapiens, ∼3.1 Gbp). Analysis of simulated and real smRNA-seq data demonstrates that mapper selection impacts differential expression results and interpretation. These results will inform on best practice for smRNA mapping and enable more accurate smRNA detection and quantification of expression and RNA editing. PMID:27284164

  19. MicroRNA mimicry blocks pulmonary fibrosis

    Science.gov (United States)

    Montgomery, Rusty L; Yu, Guoying; Latimer, Paul A; Stack, Christianna; Robinson, Kathryn; Dalby, Christina M; Kaminski, Naftali; van Rooij, Eva

    2014-01-01

    Over the last decade, great enthusiasm has evolved for microRNA (miRNA) therapeutics. Part of the excitement stems from the fact that a miRNA often regulates numerous related mRNAs. As such, modulation of a single miRNA allows for parallel regulation of multiple genes involved in a particular disease. While many studies have shown therapeutic efficacy using miRNA inhibitors, efforts to restore or increase the function of a miRNA have been lagging behind. The miR-29 family has gained a lot of attention for its clear function in tissue fibrosis. This fibroblast-enriched miRNA family is downregulated in fibrotic diseases which induces a coordinate increase of many extracellular matrix genes. Here, we show that intravenous injection of synthetic RNA duplexes can increase miR-29 levels in vivo for several days. Moreover, therapeutic delivery of these miR-29 mimics during bleomycin-induced pulmonary fibrosis restores endogenous miR-29 function whereby decreasing collagen expression and blocking and reversing pulmonary fibrosis. Our data support the feasibility of using miRNA mimics to therapeutically increase miRNAs and indicate miR-29 to be a potent therapeutic miRNA for treating pulmonary fibrosis. PMID:25239947

  20. Modulation of RNA function by aminoglycoside antibiotics.

    Science.gov (United States)

    Schroeder, R; Waldsich, C; Wank, H

    2000-01-04

    One of the most important families of antibiotics are the aminoglycosides, including drugs such as neomycin B, paromomycin, gentamicin and streptomycin. With the discovery of the catalytic potential of RNA, these antibiotics became very popular due to their RNA-binding capacity. They serve for the analysis of RNA function as well as for the study of RNA as a potential therapeutic target. Improvements in RNA structure determination recently provided first insights into the decoding site of the ribosome at high resolution and how aminoglycosides might induce misreading of the genetic code. In addition to inhibiting prokaryotic translation, aminoglycosides inhibit several catalytic RNAs such as self-splicing group I introns, RNase P and small ribozymes in vitro. Furthermore, these antibiotics interfere with human immunodeficiency virus (HIV) replication by disrupting essential RNA-protein contacts. Most exciting is the potential of many RNA-binding antibiotics to stimulate RNA activities, conceiving small-molecule partners for the hypothesis of an ancient RNA world. SELEX (systematic evolution of ligands by exponential enrichment) has been used in this evolutionary game leading to small synthetic RNAs, whose NMR structures gave valuable information on how aminoglycosides interact with RNA, which could possibly be used in applied science.

  1. Movement of regulatory RNA between animal cells.

    Science.gov (United States)

    Jose, Antony M

    2015-07-01

    Recent studies suggest that RNA can move from one cell to another and regulate genes through specific base-pairing. Mechanisms that modify or select RNA for secretion from a cell are unclear. Secreted RNA can be stable enough to be detected in the extracellular environment and can enter the cytosol of distant cells to regulate genes. Mechanisms that import RNA into the cytosol of an animal cell can enable uptake of RNA from many sources including other organisms. This role of RNA is akin to that of steroid hormones, which cross cell membranes to regulate genes. The potential diagnostic use of RNA in human extracellular fluids has ignited interest in understanding mechanisms that enable the movement of RNA between animal cells. Genetic model systems will be essential to gain more confidence in proposed mechanisms of RNA transport and to connect an extracellular RNA with a specific biological function. Studies in the worm C. elegans and in other animals have begun to reveal parts of this novel mechanism of cell-to-cell communication. Here, I summarize the current state of this nascent field, highlight the many unknowns, and suggest future directions. © 2015 Wiley Periodicals, Inc.

  2. Comparison of protocols and RNA carriers for plasma miRNA isolation. Unraveling RNA carrier influence on miRNA isolation

    Science.gov (United States)

    Martos, Laura; Fernández-Pardo, Álvaro; Oto, Julia; Medina, Pilar; España, Francisco; Navarro, Silvia

    2017-01-01

    microRNAs are promising biomarkers in biological fluids in several diseases. Different plasma RNA isolation protocols and carriers are available, but their efficiencies have been scarcely compared. Plasma microRNAs were isolated using a phenol and column-based procedure and a column-based procedure, in the presence or absence of two RNA carriers (yeast RNA and MS2 RNA). We evaluated the presence of PCR inhibitors and the relative abundance of certain microRNAs by qRT-PCR. Furthermore, we analyzed the association between different isolation protocols, the relative abundance of the miRNAs in the sample, the GC content and the free energy of microRNAs. In all microRNAs analyzed, the addition of yeast RNA as a carrier in the different isolation protocols used gave lower raw Cq values, indicating higher microRNA recovery. Moreover, this increase in microRNAs recovery was dependent on their own relative abundance in the sample, their GC content and the free-energy of their own most stable secondary structure. Furthermore, the normalization of microRNA levels by an endogenous microRNA is more reliable than the normalization by plasma volume, as it reduced the difference in microRNA fold abundance between the different isolation protocols evaluated. Our thorough study indicates that a standardization of pre- and analytical conditions is necessary to obtain reproducible inter-laboratory results in plasma microRNA studies. PMID:29077772

  3. Henipavirus RNA in African bats.

    Directory of Open Access Journals (Sweden)

    Jan Felix Drexler

    Full Text Available BACKGROUND: Henipaviruses (Hendra and Nipah virus are highly pathogenic members of the family Paramyxoviridae. Fruit-eating bats of the Pteropus genus have been suggested as their natural reservoir. Human Henipavirus infections have been reported in a region extending from Australia via Malaysia into Bangladesh, compatible with the geographic range of Pteropus. These bats do not occur in continental Africa, but a whole range of other fruit bats is encountered. One of the most abundant is Eidolon helvum, the African Straw-coloured fruit bat. METHODOLOGY/PRINCIPAL FINDINGS: Feces from E. helvum roosting in an urban setting in Kumasi/Ghana were tested for Henipavirus RNA. Sequences of three novel viruses in phylogenetic relationship to known Henipaviruses were detected. Virus RNA concentrations in feces were low. CONCLUSIONS/SIGNIFICANCE: The finding of novel putative Henipaviruses outside Australia and Asia contributes a significant extension of the region of potential endemicity of one of the most pathogenic virus genera known in humans.

  4. REDIdb: the RNA editing database.

    Science.gov (United States)

    Picardi, Ernesto; Regina, Teresa Maria Rosaria; Brennicke, Axel; Quagliariello, Carla

    2007-01-01

    The RNA Editing Database (REDIdb) is an interactive, web-based database created and designed with the aim to allocate RNA editing events such as substitutions, insertions and deletions occurring in a wide range of organisms. The database contains both fully and partially sequenced DNA molecules for which editing information is available either by experimental inspection (in vitro) or by computational detection (in silico). Each record of REDIdb is organized in a specific flat-file containing a description of the main characteristics of the entry, a feature table with the editing events and related details and a sequence zone with both the genomic sequence and the corresponding edited transcript. REDIdb is a relational database in which the browsing and identification of editing sites has been simplified by means of two facilities to either graphically display genomic or cDNA sequences or to show the corresponding alignment. In both cases, all editing sites are highlighted in colour and their relative positions are detailed by mousing over. New editing positions can be directly submitted to REDIdb after a user-specific registration to obtain authorized secure access. This first version of REDIdb database stores 9964 editing events and can be freely queried at http://biologia.unical.it/py_script/search.html.

  5. 5S rRNA-derived and tRNA-derived SINEs in fruit bats.

    Science.gov (United States)

    Gogolevsky, Konstantin P; Vassetzky, Nikita S; Kramerov, Dmitri A

    2009-05-01

    Most short retroposons (SINEs) descend from cellular tRNA of 7SL RNA. Here, four new SINEs were found in megabats (Megachiroptera) but neither in microbats nor in other mammals. Two of them, MEG-RS and MEG-RL, descend from another cellular RNA, 5S rRNA; one (MEG-T2) is a tRNA-derived SINE; and MEG-TR is a hybrid tRNA/5S rRNA SINE. Insertion locus analysis suggests that these SINEs were active in the recent fruit bat evolution. Analysis of MEG-RS and MEG-RL in comparison with other few 5S rRNA-derived SINEs demonstrates that the internal RNA polymerase III promoter is their most invariant region, while the secondary structure is more variable. The mechanisms underlying the modular structure of these and other SINEs as well as their variation are discussed. The scenario of evolution of MEG SINEs is proposed.

  6. RNA-Binding Proteins Revisited – The Emerging Arabidopsis mRNA Interactome

    KAUST Repository

    Kö ster, Tino; Marondedze, Claudius; Meyer, Katja; Staiger, Dorothee

    2017-01-01

    RNA–protein interaction is an important checkpoint to tune gene expression at the RNA level. Global identification of proteins binding in vivo to mRNA has been possible through interactome capture – where proteins are fixed to target RNAs by UV crosslinking and purified through affinity capture of polyadenylated RNA. In Arabidopsis over 500 RNA-binding proteins (RBPs) enriched in UV-crosslinked samples have been identified. As in mammals and yeast, the mRNA interactomes came with a few surprises. For example, a plethora of the proteins caught on RNA had not previously been linked to RNA-mediated processes, for example proteins of intermediary metabolism. Thus, the studies provide unprecedented insights into the composition of the mRNA interactome, highlighting the complexity of RNA-mediated processes.

  7. RNA-Binding Proteins Revisited – The Emerging Arabidopsis mRNA Interactome

    KAUST Repository

    Köster, Tino

    2017-04-13

    RNA–protein interaction is an important checkpoint to tune gene expression at the RNA level. Global identification of proteins binding in vivo to mRNA has been possible through interactome capture – where proteins are fixed to target RNAs by UV crosslinking and purified through affinity capture of polyadenylated RNA. In Arabidopsis over 500 RNA-binding proteins (RBPs) enriched in UV-crosslinked samples have been identified. As in mammals and yeast, the mRNA interactomes came with a few surprises. For example, a plethora of the proteins caught on RNA had not previously been linked to RNA-mediated processes, for example proteins of intermediary metabolism. Thus, the studies provide unprecedented insights into the composition of the mRNA interactome, highlighting the complexity of RNA-mediated processes.

  8. Construction of RNA nanocages by re-engineering the packaging RNA of Phi29 bacteriophage

    Science.gov (United States)

    Hao, Chenhui; Li, Xiang; Tian, Cheng; Jiang, Wen; Wang, Guansong; Mao, Chengde

    2014-05-01

    RNA nanotechnology promises rational design of RNA nanostructures with wide array of structural diversities and functionalities. Such nanostructures could be used in applications such as small interfering RNA delivery and organization of in vivo chemical reactions. Though having impressive development in recent years, RNA nanotechnology is still quite limited and its programmability and complexity could not rival the degree of its closely related cousin: DNA nanotechnology. Novel strategies are needed for programmed RNA self-assembly. Here, we have assembled RNA nanocages by re-engineering a natural, biological RNA motif: the packaging RNA of phi29 bacteriophage. The resulting RNA nanostructures have been thoroughly characterized by gel electrophoresis, cryogenic electron microscopy imaging and dynamic light scattering.

  9. Role of RNase MRP in viral RNA degradation and RNA recombination.

    Science.gov (United States)

    Jaag, Hannah M; Lu, Qiasheng; Schmitt, Mark E; Nagy, Peter D

    2011-01-01

    RNA degradation, together with RNA synthesis, controls the steady-state level of viral RNAs in infected cells. The endoribonucleolytic cleavage of viral RNA is important not only for viral RNA degradation but for RNA recombination as well, due to the participation of some RNA degradation products in the RNA recombination process. To identify host endoribonucleases involved in degradation of Tomato bushy stunt virus (TBSV) in a Saccharomyces cerevisiae model host, we tested eight known endoribonucleases. Here we report that downregulation of SNM1, encoding a component of the RNase MRP, and a temperature-sensitive mutation in the NME1 gene, coding for the RNA component of RNase MRP, lead to reduced production of the endoribonucleolytically cleaved TBSV RNA in yeast. We also show that the highly purified yeast RNase MRP cleaves the TBSV RNA in vitro, resulting in TBSV RNA degradation products similar in size to those observed in yeast cells. Knocking down the NME1 homolog in Nicotiana benthamiana also led to decreased production of the cleaved TBSV RNA, suggesting that in plants, RNase MRP is involved in TBSV RNA degradation. Altogether, this work suggests a role for the host endoribonuclease RNase MRP in viral RNA degradation and recombination.

  10. Fragment-based modelling of single stranded RNA bound to RNA recognition motif containing proteins

    Science.gov (United States)

    de Beauchene, Isaure Chauvot; de Vries, Sjoerd J.; Zacharias, Martin

    2016-01-01

    Abstract Protein-RNA complexes are important for many biological processes. However, structural modeling of such complexes is hampered by the high flexibility of RNA. Particularly challenging is the docking of single-stranded RNA (ssRNA). We have developed a fragment-based approach to model the structure of ssRNA bound to a protein, based on only the protein structure, the RNA sequence and conserved contacts. The conformational diversity of each RNA fragment is sampled by an exhaustive library of trinucleotides extracted from all known experimental protein–RNA complexes. The method was applied to ssRNA with up to 12 nucleotides which bind to dimers of the RNA recognition motifs (RRMs), a highly abundant eukaryotic RNA-binding domain. The fragment based docking allows a precise de novo atomic modeling of protein-bound ssRNA chains. On a benchmark of seven experimental ssRNA–RRM complexes, near-native models (with a mean heavy-atom deviation of <3 Å from experiment) were generated for six out of seven bound RNA chains, and even more precise models (deviation < 2 Å) were obtained for five out of seven cases, a significant improvement compared to the state of the art. The method is not restricted to RRMs but was also successfully applied to Pumilio RNA binding proteins. PMID:27131381

  11. The use of 125iodine-labeled RNA for detection of the RNA binding to ribosomes

    International Nuclear Information System (INIS)

    Mori, Tomohiko; Fukuda, Mitsuru

    1975-01-01

    The in vitro labeling of RNA with radioactive iodine is the efficient method to obtain the RNA with high specific activity. The present paper reports on the application of this technique to the production of iodine-labeled RNA for use in the experiment of binding RNA to ribosomes. Tobacco mosaic virus (TMV) RNA was used as natural mRNA, and E. coli S-30 preparation was used as a source of ribosomes. The TMV-RNA was prepared by bentonite-phenol extraction from TMV, and the method used for the iodation of RNA was based on the procedure described by Getz et al. The iodine-labeled RNA was incubated in a cell-free protein synthesizing system (S-30) prepared from E. coli K-12. After the incubation, the reaction mixture was layered onto sucrose gradient, centrifuged, and fractionated into 18 fractions. Optical density at 260 nm was measured, and radioactivity was counted, for each fraction. The binding of mRNA to ribosomes occurred even at 0 deg C, and the occurrence of the nonspecific binding was also shown. Consequently, the specific binding, i.e. the formation of the initiation complex being involved in amino acid incorporation, may be estimated by subtracting the radioactivity associated with monosomes in the presence of both rRNA and ATA from that in the presence of rRNA only. It was shown that the iodine-labeled RNA can be used for the studies of binding RNA to ribosomes. (Kako, I.)

  12. Deep Sequencing Insights in Therapeutic shRNA Processing and siRNA Target Cleavage Precision.

    Science.gov (United States)

    Denise, Hubert; Moschos, Sterghios A; Sidders, Benjamin; Burden, Frances; Perkins, Hannah; Carter, Nikki; Stroud, Tim; Kennedy, Michael; Fancy, Sally-Ann; Lapthorn, Cris; Lavender, Helen; Kinloch, Ross; Suhy, David; Corbau, Romu

    2014-02-04

    TT-034 (PF-05095808) is a recombinant adeno-associated virus serotype 8 (AAV8) agent expressing three short hairpin RNA (shRNA) pro-drugs that target the hepatitis C virus (HCV) RNA genome. The cytosolic enzyme Dicer cleaves each shRNA into multiple, potentially active small interfering RNA (siRNA) drugs. Using next-generation sequencing (NGS) to identify and characterize active shRNAs maturation products, we observed that each TT-034-encoded shRNA could be processed into as many as 95 separate siRNA strands. Few of these appeared active as determined by Sanger 5' RNA Ligase-Mediated Rapid Amplification of cDNA Ends (5-RACE) and through synthetic shRNA and siRNA analogue studies. Moreover, NGS scrutiny applied on 5-RACE products (RACE-seq) suggested that synthetic siRNAs could direct cleavage in not one, but up to five separate positions on targeted RNA, in a sequence-dependent manner. These data support an on-target mechanism of action for TT-034 without cytotoxicity and question the accepted precision of substrate processing by the key RNA interference (RNAi) enzymes Dicer and siRNA-induced silencing complex (siRISC).Molecular Therapy-Nucleic Acids (2014) 3, e145; doi:10.1038/mtna.2013.73; published online 4 February 2014.

  13. Disruption of Specific RNA-RNA Interactions in a Double-Stranded RNA Virus Inhibits Genome Packaging and Virus Infectivity.

    Science.gov (United States)

    Fajardo, Teodoro; Sung, Po-Yu; Roy, Polly

    2015-12-01

    Bluetongue virus (BTV) causes hemorrhagic disease in economically important livestock. The BTV genome is organized into ten discrete double-stranded RNA molecules (S1-S10) which have been suggested to follow a sequential packaging pathway from smallest to largest segment during virus capsid assembly. To substantiate and extend these studies, we have investigated the RNA sorting and packaging mechanisms with a new experimental approach using inhibitory oligonucleotides. Putative packaging signals present in the 3'untranslated regions of BTV segments were targeted by a number of nuclease resistant oligoribonucleotides (ORNs) and their effects on virus replication in cell culture were assessed. ORNs complementary to the 3' UTR of BTV RNAs significantly inhibited virus replication without affecting protein synthesis. Same ORNs were found to inhibit complex formation when added to a novel RNA-RNA interaction assay which measured the formation of supramolecular complexes between and among different RNA segments. ORNs targeting the 3'UTR of BTV segment 10, the smallest RNA segment, were shown to be the most potent and deletions or substitution mutations of the targeted sequences diminished the RNA complexes and abolished the recovery of viable viruses using reverse genetics. Cell-free capsid assembly/RNA packaging assay also confirmed that the inhibitory ORNs could interfere with RNA packaging and further substitution mutations within the putative RNA packaging sequence have identified the recognition sequence concerned. Exchange of 3'UTR between segments have further demonstrated that RNA recognition was segment specific, most likely acting as part of the secondary structure of the entire genomic segment. Our data confirm that genome packaging in this segmented dsRNA virus occurs via the formation of supramolecular complexes formed by the interaction of specific sequences located in the 3' UTRs. Additionally, the inhibition of packaging in-trans with inhibitory ORNs

  14. Spathebothriidea: survey of species, scolex and egg morphology, and interrelationships of a non-segmented, relictual tapeworm group (Platyhelminthes: Cestoda)

    Czech Academy of Sciences Publication Activity Database

    Kuchta, Roman; Pearson, R.; Scholz, Tomáš; Ditrich, O.; Olson, P. D.

    2014-01-01

    Roč. 61, č. 4 (2014), s. 331-346 ISSN 0015-5683 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Eucestoda * taxonomy * scanning electron microscopy * 28S rDNA * 18S rDNA * ITS2 * phylogenetic relationships * phylogenetic relationships Subject RIV: EG - Zoology Impact factor: 1.147, year: 2014

  15. Argonaute: The executor of small RNA function.

    Science.gov (United States)

    Azlan, Azali; Dzaki, Najat; Azzam, Ghows

    2016-08-20

    The discovery of small non-coding RNAs - microRNA (miRNA), short interfering RNA (siRNA) and PIWI-interacting RNA (piRNA) - represents one of the most exciting frontiers in biology specifically on the mechanism of gene regulation. In order to execute their functions, these small RNAs require physical interactions with their protein partners, the Argonaute (AGO) family proteins. Over the years, numerous studies have made tremendous progress on understanding the roles of AGO in gene silencing in various organisms. In this review, we summarize recent progress of AGO-mediated gene silencing and other cellular processes in which AGO proteins have been implicated with a particular focus on progress made in flies, humans and other model organisms as compliment. Copyright © 2016 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

  16. Designing synthetic RNA for delivery by nanoparticles

    International Nuclear Information System (INIS)

    Jedrzejczyk, Dominika; Pawlowska, Roza; Chworos, Arkadiusz; Gendaszewska-Darmach, Edyta

    2017-01-01

    The rapid development of synthetic biology and nanobiotechnology has led to the construction of various synthetic RNA nanoparticles of different functionalities and potential applications. As they occur naturally, nucleic acids are an attractive construction material for biocompatible nanoscaffold and nanomachine design. In this review, we provide an overview of the types of RNA and nucleic acid’s nanoparticle design, with the focus on relevant nanostructures utilized for gene-expression regulation in cellular models. Structural analysis and modeling is addressed along with the tools available for RNA structural prediction. The functionalization of RNA-based nanoparticles leading to prospective applications of such constructs in potential therapies is shown. The route from the nanoparticle design and modeling through synthesis and functionalization to cellular application is also described. For a better understanding of the fate of targeted RNA after delivery, an overview of RNA processing inside the cell is also provided. (topical review)

  17. Predicting RNA Structure Using Mutual Information

    DEFF Research Database (Denmark)

    Freyhult, E.; Moulton, V.; Gardner, P. P.

    2005-01-01

    , to display and predict conserved RNA secondary structure (including pseudoknots) from an alignment. Results: We show that MIfold can be used to predict simple pseudoknots, and that the performance can be adjusted to make it either more sensitive or more selective. We also demonstrate that the overall...... package. Conclusion: MIfold provides a useful supplementary tool to programs such as RNA Structure Logo, RNAalifold and COVE, and should be useful for automatically generating structural predictions for databases such as Rfam. Availability: MIfold is freely available from http......Background: With the ever-increasing number of sequenced RNAs and the establishment of new RNA databases, such as the Comparative RNA Web Site and Rfam, there is a growing need for accurately and automatically predicting RNA structures from multiple alignments. Since RNA secondary structure...

  18. Preparation of Total RNA from Fission Yeast.

    Science.gov (United States)

    Bähler, Jürg; Wise, Jo Ann

    2017-04-03

    Treatment with hot phenol breaks open fission yeast cells and begins to strip away bound proteins from RNA. Deproteinization is completed by multiple extractions with chloroform/isoamyl alcohol and separation of the aqueous and organic phases using MaXtract gel, an inert material that acts as a physical barrier between the phases. The final step is concentration of the RNA by ethanol precipitation. The protocol can be used to prepare RNA from several cultures grown in parallel, but it is important not to process too many samples at once because delays can be detrimental to RNA quality. A reasonable number of samples to process at once would be three to four for microarray or RNA sequencing analyses and six for preliminary investigations of mutants implicated in RNA metabolism. © 2017 Cold Spring Harbor Laboratory Press.

  19. A probabilistic model of RNA conformational space

    DEFF Research Database (Denmark)

    Frellsen, Jes; Moltke, Ida; Thiim, Martin

    2009-01-01

    efficient sampling of RNA conformations in continuous space, and with associated probabilities. We show that the model captures several key features of RNA structure, such as its rotameric nature and the distribution of the helix lengths. Furthermore, the model readily generates native-like 3-D......, the discrete nature of the fragments necessitates the use of carefully tuned, unphysical energy functions, and their non-probabilistic nature impairs unbiased sampling. We offer a solution to the sampling problem that removes these important limitations: a probabilistic model of RNA structure that allows......The increasing importance of non-coding RNA in biology and medicine has led to a growing interest in the problem of RNA 3-D structure prediction. As is the case for proteins, RNA 3-D structure prediction methods require two key ingredients: an accurate energy function and a conformational sampling...

  20. RNA-Binding Proteins in Plant Immunity

    Directory of Open Access Journals (Sweden)

    Virginia Woloshen

    2011-01-01

    Full Text Available Plant defence responses against pathogen infection are crucial to plant survival. The high degree of regulation of plant immunity occurs both transcriptionally and posttranscriptionally. Once transcribed, target gene RNA must be processed prior to translation. This includes polyadenylation, 5′capping, editing, splicing, and mRNA export. RNA-binding proteins (RBPs have been implicated at each level of RNA processing. Previous research has primarily focused on structural RNA-binding proteins of yeast and mammals; however, more recent work has characterized a number of plant RBPs and revealed their roles in plant immune responses. This paper provides an update on the known functions of RBPs in plant immune response regulation. Future in-depth analysis of RBPs and other related players will unveil the sophisticated regulatory mechanisms of RNA processing during plant immune responses.

  1. The Old and New RNA World

    Directory of Open Access Journals (Sweden)

    Zofia Szweykowska-Kulińska

    2014-12-01

    Full Text Available Among the numerous hypotheses offering a scenario for the origin of life on Earth, the one called “The RNA World” has gained the most attention. According to this hypothesis RNA acted as a genetic information storage material, as a catalyst of all metabolic reactions, and as a regulator of all processes in the primordial world. Various experiments show that RNA molecules could have been synthesized abiotically, with the potential to mediate a whole repertoire of metabolic reactions. Ribozymes carrying out aminoacyl-tRNA reactions have been found in SELEX (systematic evolution of ligands by exponential enrichment approaches and the development of a ribosome from a RNA-built protoribosome is easy to imagine. Transfer RNA aminoacylation, protoribosome origin, and the availability of amino acids on early Earth allowed the genetic code to evolve. Encoded proteins most likely stabilized RNA molecules and were able to create channels across membranes. In the modern cell, DNA replaced RNA as the main depositor of genetic information and proteins carry out almost all metabolic reactions. However, RNA is still playing versatile, crucial roles in the cell. Apart from its classical functions in the cell, a huge small RNA world is controlling gene expression, chromatin condensation, response to environmental cues, and protecting the cell against the invasion of various nucleic acids forms. Long non-coding RNAs act as crucial gene expression regulators. Riboswitches act at the level of transcription, splicing or translation and mediate feedback regulation on biosynthesis and transport of the ligand they sense. Alternative splicing generates genetic variability and increases the protein repertoire in response to developmental or environmental changes. All these regulatory functions are essential in shaping cell plasticity in the changing milieu. Recent discoveries of new, unexpected and important functions of RNA molecules support the hypothesis that we

  2. Inverse folding of RNA pseudoknot structures

    Directory of Open Access Journals (Sweden)

    Li Linda YM

    2010-06-01

    Full Text Available Abstract Background RNA exhibits a variety of structural configurations. Here we consider a structure to be tantamount to the noncrossing Watson-Crick and G-U-base pairings (secondary structure and additional cross-serial base pairs. These interactions are called pseudoknots and are observed across the whole spectrum of RNA functionalities. In the context of studying natural RNA structures, searching for new ribozymes and designing artificial RNA, it is of interest to find RNA sequences folding into a specific structure and to analyze their induced neutral networks. Since the established inverse folding algorithms, RNAinverse, RNA-SSD as well as INFO-RNA are limited to RNA secondary structures, we present in this paper the inverse folding algorithm Inv which can deal with 3-noncrossing, canonical pseudoknot structures. Results In this paper we present the inverse folding algorithm Inv. We give a detailed analysis of Inv, including pseudocodes. We show that Inv allows to design in particular 3-noncrossing nonplanar RNA pseudoknot 3-noncrossing RNA structures-a class which is difficult to construct via dynamic programming routines. Inv is freely available at http://www.combinatorics.cn/cbpc/inv.html. Conclusions The algorithm Inv extends inverse folding capabilities to RNA pseudoknot structures. In comparison with RNAinverse it uses new ideas, for instance by considering sets of competing structures. As a result, Inv is not only able to find novel sequences even for RNA secondary structures, it does so in the context of competing structures that potentially exhibit cross-serial interactions.

  3. Functional characterization of the Drosophila MRP (mitochondrial RNA processing) RNA gene.

    Science.gov (United States)

    Schneider, Mary D; Bains, Anupinder K; Rajendra, T K; Dominski, Zbigniew; Matera, A Gregory; Simmonds, Andrew J

    2010-11-01

    MRP RNA is a noncoding RNA component of RNase mitochondrial RNA processing (MRP), a multi-protein eukaryotic endoribonuclease reported to function in multiple cellular processes, including ribosomal RNA processing, mitochondrial DNA replication, and cell cycle regulation. A recent study predicted a potential Drosophila ortholog of MRP RNA (CR33682) by computer-based genome analysis. We have confirmed the expression of this gene and characterized the phenotype associated with this locus. Flies with mutations that specifically affect MRP RNA show defects in growth and development that begin in the early larval period and end in larval death during the second instar stage. We present several lines of evidence demonstrating a role for Drosophila MRP RNA in rRNA processing. The nuclear fraction of Drosophila MRP RNA localizes to the nucleolus. Further, a mutant strain shows defects in rRNA processing that include a defect in 5.8S rRNA processing, typical of MRP RNA mutants in other species, as well as defects in early stages of rRNA processing.

  4. RAID: a comprehensive resource for human RNA-associated (RNA–RNA/RNA–protein) interaction

    Science.gov (United States)

    Zhang, Xiaomeng; Wu, Deng; Chen, Liqun; Li, Xiang; Yang, Jinxurong; Fan, Dandan; Dong, Tingting; Liu, Mingyue; Tan, Puwen; Xu, Jintian; Yi, Ying; Wang, Yuting; Zou, Hua; Hu, Yongfei; Fan, Kaili; Kang, Juanjuan; Huang, Yan; Miao, Zhengqiang; Bi, Miaoman; Jin, Nana; Li, Kongning; Li, Xia; Xu, Jianzhen; Wang, Dong

    2014-01-01

    Transcriptomic analyses have revealed an unexpected complexity in the eukaryote transcriptome, which includes not only protein-coding transcripts but also an expanding catalog of noncoding RNAs (ncRNAs). Diverse coding and noncoding RNAs (ncRNAs) perform functions through interaction with each other in various cellular processes. In this project, we have developed RAID (http://www.rna-society.org/raid), an RNA-associated (RNA–RNA/RNA–protein) interaction database. RAID intends to provide the scientific community with all-in-one resources for efficient browsing and extraction of the RNA-associated interactions in human. This version of RAID contains more than 6100 RNA-associated interactions obtained by manually reviewing more than 2100 published papers, including 4493 RNA–RNA interactions and 1619 RNA–protein interactions. Each entry contains detailed information on an RNA-associated interaction, including RAID ID, RNA/protein symbol, RNA/protein categories, validated method, expressing tissue, literature references (Pubmed IDs), and detailed functional description. Users can query, browse, analyze, and manipulate RNA-associated (RNA–RNA/RNA–protein) interaction. RAID provides a comprehensive resource of human RNA-associated (RNA–RNA/RNA–protein) interaction network. Furthermore, this resource will help in uncovering the generic organizing principles of cellular function network. PMID:24803509

  5. Peptides as catalysts in the RNA world

    DEFF Research Database (Denmark)

    Wieczorek, Rafal; Dörr, Mark; Luisi, Pier Luigi

    The emergence of RNA chains from prebiotic soup is considered a stumbling block in the RNA world theory (Orgel 2004). Both the activation of RNA monomers and their subsequent oligomerization is hard to achieve in accepted early Earth conditions, thus putting doubt on the prebiotic plausibility...... chemistry and the RNA world. Prebiotic soup likely contained complex mixtures of various molecules. Interaction of peptides and nucleotides shows that we should give more consideration to systems chemistry approach in the origin-of-life research. Gorlero M, Wieczorek R, Adamala K, Giorgi A, Schininà ME...

  6. Emerging connections between RNA and autophagy

    DEFF Research Database (Denmark)

    Frankel, Lisa B; Lubas, Michal; Lund, Anders H

    2017-01-01

    in yeast, plants and animals, reviewing the molecular mechanisms and biological importance in normal physiology, stress and disease. In addition, we explore emerging evidence of core autophagy regulation mediated by RNA-binding proteins and noncoding RNAs, and point to gaps in our current knowledge......Macroautophagy/autophagy is a key catabolic process, essential for maintaining cellular homeostasis and survival through the removal and recycling of unwanted cellular material. Emerging evidence has revealed intricate connections between the RNA and autophagy research fields. While a majority...... of the connection between RNA and autophagy. Finally, we discuss the pathological implications of RNA-protein aggregation, primarily in the context of neurodegenerative disease....

  7. MiRNA Biogenesis and Intersecting Pathways

    DEFF Research Database (Denmark)

    Ben Chaabane, Samir

    MicroRNAs (miRNAs) are small non-coding RNAs that function as guide molecules in RNA silencing. Plant miRNAs are critical for plant growth, development and stress response, and are processed in Arabidopsis from primary miRNA transcripts (pri-miRNAs) by the endonuclease activity of the DICER-LIKE1...... questions need to be addressed to establish a valid link, we provide encouraging evidence of the involvement of chromatin remodeling factors FAS1 and FAS2 in miRNA biogenesis. Together, we have expanded our understanding of the intersections between miRNA biogenesis and other pathways....

  8. Personalized RNA Medicine for Pancreatic Cancer.

    Science.gov (United States)

    Gilles, Maud-Emmanuelle; Hao, Liangliang; Huang, Ling; Rupaimoole, Rajesha; Lopez-Casas, Pedro P; Pulver, Emilia; Jeong, Jong Cheol; Muthuswamy, Senthil K; Hidalgo, Manuel; Bhatia, Sangeeta N; Slack, Frank J

    2018-04-01

    Purpose: Since drug responses vary between patients, it is crucial to develop pre-clinical or co-clinical strategies that forecast patient response. In this study, we tested whether RNA-based therapeutics were suitable for personalized medicine by using patient-derived-organoid (PDO) and patient-derived-xenograft (PDX) models. Experimental Design: We performed microRNA (miRNA) profiling of PDX samples to determine the status of miRNA deregulation in individual pancreatic ductal adenocarcinoma (PDAC) patients. To deliver personalized RNA-based-therapy targeting oncogenic miRNAs that form part of this common PDAC miRNA over-expression signature, we packaged antimiR oligonucleotides against one of these miRNAs in tumor-penetrating nanocomplexes (TPN) targeting cell surface proteins on PDAC tumors. Results: As a validation for our pre-clinical strategy, the therapeutic potential of one of our nano-drugs, TPN-21, was first shown to decrease tumor cell growth and survival in PDO avatars for individual patients, then in their PDX avatars. Conclusions: This general approach appears suitable for co-clinical validation of personalized RNA medicine and paves the way to prospectively identify patients with eligible miRNA profiles for personalized RNA-based therapy. Clin Cancer Res; 24(7); 1734-47. ©2018 AACR . ©2018 American Association for Cancer Research.

  9. mRNA processing in yeast

    International Nuclear Information System (INIS)

    Stevens, A.

    1982-01-01

    Investigations in this laboratory center on basic enzymatic reactions of RNA. Still undefined are reactions involved in the conversion of precursors of mRA (pre-mRNA) to mRNA in eukaryotes. The pre-mRNA is called heterogeneous nuclear RNA and is 2 to 6 times larger than mRNA. The conversion, called splicing, involves a removal of internal sequences called introns by endoribonuclease action followed by a rejoining of the 3'- and 5'-end fragments, called exons, by ligating activity. It has not been possible yet to study the enzymes involved in vitro. Also undefined are reactions involved in the turnover or discarding of certain of the pre-mRNA molecules. Yeast is a simple eukaryote and may be expected to have the same, but perhaps simpler, processing reactions as the higher eukaryotes. Two enzymes involved in the processing of pre-mRNA and mRNA in yeast are under investigation. Both enzymes have been partially purified from ribonucleoprotein particles of yeast. The first is a unique decapping enzyme which cleaves [ 3 H]m 7 Gppp [ 14 C]RNA-poly (A) of yeast, yielding [ 3 H]m 7 GDP and is suggested by the finding that the diphosphate product, m 7 GpppA(G), and UDP-glucose are not hydrolyzed. The second enzyme is an endoribonuclease which converts both the [ 3 H] and [ 14 C] labels of [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) from an oligo(dT)-cellulose bound form to an unbound, acid-insoluble form. Results show that the stimulation involves an interaction of the labeled RNA with the small nuclear RNA. The inhibition of the enzyme by ethidium bromide and its stimulation by small nuclear RNA suggest that it may be a processing ribonuclease, requiring specific double-stranded features in its substrate. The characterization of the unique decapping enzyme and endoribonuclease may help to understand reactions involved in the processing of pre-mRNA and mRNA in eukaryotes

  10. MicroRNA delivery for regenerative medicine.

    Science.gov (United States)

    Peng, Bo; Chen, Yongming; Leong, Kam W

    2015-07-01

    MicroRNA (miRNA) directs post-transcriptional regulation of a network of genes by targeting mRNA. Although relatively recent in development, many miRNAs direct differentiation of various stem cells including induced pluripotent stem cells (iPSCs), a major player in regenerative medicine. An effective and safe delivery of miRNA holds the key to translating miRNA technologies. Both viral and nonviral delivery systems have seen success in miRNA delivery, and each approach possesses advantages and disadvantages. A number of studies have demonstrated success in augmenting osteogenesis, improving cardiogenesis, and reducing fibrosis among many other tissue engineering applications. A scaffold-based approach with the possibility of local and sustained delivery of miRNA is particularly attractive since the physical cues provided by the scaffold may synergize with the biochemical cues induced by miRNA therapy. Herein, we first briefly cover the application of miRNA to direct stem cell fate via replacement and inhibition therapies, followed by the discussion of the promising viral and nonviral delivery systems. Next we present the unique advantages of a scaffold-based delivery in achieving lineage-specific differentiation and tissue development. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Messenger RNA 3' end formation in plants.

    Science.gov (United States)

    Hunt, A G

    2008-01-01

    Messenger RNA 3' end formation is an integral step in the process that gives rise to mature, translated messenger RNAs in eukaryotes. With this step, a pre-messenger RNA is processed and polyadenylated, giving rise to a mature mRNA bearing the characteristic poly(A) tract. The poly(A) tract is a fundamental feature of mRNAs, participating in the process of translation initiation and being the focus of control mechanisms that define the lifetime of mRNAs. Thus messenger RNA 3' end formation impacts two steps in mRNA biogenesis and function. Moreover, mRNA 3' end formation is something of a bridge that integrates numerous other steps in mRNA biogenesis and function. While the process is essential for the expression of most genes, it is also one that is subject to various forms of regulation, such that both quantitative and qualitative aspects of gene expression may be modulated via the polyadenylation complex. In this review, the current status of understanding of mRNA 3' end formation in plants is discussed. In particular, the nature of mRNA 3' ends in plants is reviewed, as are recent studies that are beginning to yield insight into the functioning and regulation of plant polyadenylation factor subunits.

  12. Exploring RNA structure by integrative molecular modelling

    DEFF Research Database (Denmark)

    Masquida, Benoît; Beckert, Bertrand; Jossinet, Fabrice

    2010-01-01

    RNA molecular modelling is adequate to rapidly tackle the structure of RNA molecules. With new structured RNAs constituting a central class of cellular regulators discovered every year, the need for swift and reliable modelling methods is more crucial than ever. The pragmatic method based...... on interactive all-atom molecular modelling relies on the observation that specific structural motifs are recurrently found in RNA sequences. Once identified by a combination of comparative sequence analysis and biochemical data, the motifs composing the secondary structure of a given RNA can be extruded...

  13. The modification of siRNA with 3' cholesterol to increase nuclease protection and suppression of native mRNA by select siRNA polyplexes.

    Science.gov (United States)

    Ambardekar, Vishakha V; Han, Huai-Yun; Varney, Michelle L; Vinogradov, Serguei V; Singh, Rakesh K; Vetro, Joseph A

    2011-02-01

    Polymer-siRNA complexes (siRNA polyplexes) are being actively developed to improve the therapeutic application of siRNA. A major limitation for many siRNA polyplexes, however, is insufficient mRNA suppression. Given that modifying the sense strand of siRNA with 3' cholesterol (chol-siRNA) increases the activity of free nuclease-resistant siRNA in vitro and in vivo, we hypothesized that complexation of chol-siRNA can increase mRNA suppression by siRNA polyplexes. In this study, the characteristics and siRNA activity of self assembled polyplexes formed with chol-siRNA or unmodified siRNA were compared using three types of conventional, positively charged polymers: (i) biodegradable, cross-linked nanogels (BDNG) (ii) graft copolymers (PEI-PEG), and (iii) linear block copolymers (PLL10-PEG, and PLL50-PEG). Chol-siRNA did not alter complex formation or the resistance of polyplexes to siRNA displacement by heparin but increased nuclease protection by BDNG, PLL10-PEG, and PLL50-PEG polyplexes over polyplexes with unmodified siRNA. Chol-CYPB siRNA increased suppression of native CYPB mRNA in mammary microvascular endothelial cells (MVEC) by BDNG polyplexes (35%) and PLL10-PEG polyplexes (69%) over comparable CYPB siRNA polyplexes but had no effect on PEI-PEG or PLL50-PEG polyplexes. Overall, these results indicate that complexation of chol-siRNA increases nuclease protection and mRNA suppression by select siRNA polyplexes. These results also suggest that polycationic block length is an important factor in increasing mRNA suppression by PLL-PEG chol-siRNA polyplexes in mammary MVEC. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. The Modification of siRNA with 3′ Cholesterol to Increase Nuclease Protection and Suppression of Native mRNA by Select siRNA Polyplexes

    Science.gov (United States)

    Ambardekar, Vishakha V.; Han, Huai-Yun; Varney, Michelle L.; Vinogradov, Serguei V.; Singh, Rakesh K.; Vetro, Joseph A.

    2010-01-01

    Polymer-siRNA complexes (siRNA polyplexes) are being actively developed to improve the therapeutic application of siRNA. A major limitation for many siRNA polyplexes, however, is insufficient mRNA suppression. Given that modifying the sense strand of siRNA with 3′ cholesterol (chol-siRNA) increases the activity of free nuclease-resistant siRNA in vitro and in vivo, we hypothesized that complexation of chol-siRNA can increase mRNA suppression by siRNA polyplexes. In this study, the characteristics and siRNA activity of self assembled polyplexes formed with chol-siRNA or unmodified siRNA were compared using three types of conventional, positively charged polymers: (i) biodegradable, cross-linked nanogels (BDNG) (ii) graft copolymers (PEI-PEG), and (iii) linear block copolymers (PLL10-PEG, and PLL50-PEG). Chol-siRNA did not alter complex formation or the resistance of polyplexes to siRNA displacement by heparin but increased nuclease protection by BDNG, PLL10-PEG, and PLL50-PEG polyplexes over polyplexes with unmodified siRNA. Chol-CYPB siRNA increased suppression of native CYPB mRNA in mammary microvascular endothelial cells (MVEC) by BDNG polyplexes (35%) and PLL10-PEG polyplexes (69%) over comparable CYPB siRNA polyplexes but had no effect on PEI-PEG or PLL50-PEG polyplexes. Overall, these results indicate that complexation of chol-siRNA increases nuclease protection and mRNA suppression by select siRNA polyplexes. These results also suggest that polycationic block length is an important factor in increasing mRNA suppression by PLL-PEG chol-siRNA polyplexes in mammary MVEC. PMID:21047680

  15. RNA-DNA Differences Are Generated in Human Cells within Seconds after RNA Exits Polymerase II

    Directory of Open Access Journals (Sweden)

    Isabel X. Wang

    2014-03-01

    Full Text Available RNA sequences are expected to be identical to their corresponding DNA sequences. Here, we found all 12 types of RNA-DNA sequence differences (RDDs in nascent RNA. Our results show that RDDs begin to occur in RNA chains ∼55 nt from the RNA polymerase II (Pol II active site. These RDDs occur so soon after transcription that they are incompatible with known deaminase-mediated RNA-editing mechanisms. Moreover, the 55 nt delay in appearance indicates that they do not arise during RNA synthesis by Pol II or as a direct consequence of modified base incorporation. Preliminary data suggest that RDD and R-loop formations may be coupled. These findings identify sequence substitution as an early step in cotranscriptional RNA processing.

  16. RNA three-way junctions can act as flexible RNA structural elements in large RNA molecules: a molecular simulation analysis

    Czech Academy of Sciences Publication Activity Database

    Beššeová, Ivana; Réblová, Kamila; Leontis, N.B.; Šponer, Jiří

    2009-01-01

    Roč. 26, č. 6 (2009), s. 830-831 ISSN 0739-1102. [The 17th Conversation . 16.06.2009-20.06.2009, Albany] Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : RNA three-way junctions * RNA Subject RIV: BO - Biophysics

  17. The HIV-1 leader RNA conformational switch regulates RNA dimerization but does not regulate mRNA translation

    NARCIS (Netherlands)

    Abbink, Truus E. M.; Ooms, Marcel; Haasnoot, P. C. Joost; Berkhout, Ben

    2005-01-01

    The untranslated leader RNA is the most conserved part of the human immunodeficiency virus type I (HIV-1) genome. It contains many regulatory motifs that mediate a variety of steps in the viral life cycle. Previous work showed that the full-length leader RNA can adopt two alternative structures: a

  18. In vitro transcription of Sonchus yellow net virus RNA by a virus-associated RNA-dependent RNA polymerase

    NARCIS (Netherlands)

    Flore, P.H.

    1986-01-01

    The aim of the investigation presented in this thesis was to elucidate the nature of the RNA- dependent RNA polymerase, thought to be associated with Sonchus yellow net virus (SYNV), a rhabdovirus infecting plants. This research was initiated to shed light on the

  19. [Satellite RNA (RNA3) of tomato black ring virus is found with one of the 2 major RNAs (RNA2) in a new capsid nucleoprotein].

    Science.gov (United States)

    Doz, B; Dunez, J; Bove, J M

    1977-12-19

    Tomato Black Ring Virus (TBRV) like other NEPOviruses posseses two nucleoproteins M and B and two major RNAs, RNA1 and RNA2 respectively distributed in B and M. A new nucleoprotein has just been discovered and comprises one molecule of RNA2 associated with one molecule of RNA3. RNA3 is a small RNA of molecular weight 500,000 d considered to be a satellite RNA. Its level appears to depend on the infection stage, local or systemic. RNA3 is able to modify the relative proportions of nucleoproteins M and B and their respective RNAs. The satellite RNA, might be part of the genome and represent a monocistronic mRNA for protein capsid synthesis. However it seems perhaps more tempting to correlate TBRV-RNA3 with satellite RNA5 of certain strains of Cucumber mosaic virus.

  20. Alterations in messenger RNA and small nuclear RNA metabolism resulting from fluorouracil incorporation

    International Nuclear Information System (INIS)

    Armstrong, R.D.; Cadman, E.C.

    1985-01-01

    Studies were completed to examine the effect of 5-fluorouracil (FUra) incorporation on messenger RNA (mRNA) and small molecular weight nuclear RNA (SnRNA) metabolism. Studies of mRNA were completed using cDNA-mRNA hybridization methods to specifically examine dihydrofolate reductase (DHFR) mRNA. C 3 -L5178Y murine leukemia cells which are gene-amplified for DHFR, were exposed to FUra for 6, 12 or 24 hr, and the nuclear and cytoplasmic levels of DHFR-mRNA determined by hybridization with 32 P-DHFR-cDNA. FUra produced a dose-dependent increase in nuclear DHFR-mRNA levels, while total cytoplasmic DHFR-mRNA levels appeared to be unchanged. To examine only mRNA synthesized during FUra exposure, cells were also treated concurrently with [ 3 H] cytidine, and the [ 3 H]mRNA-cDNA hybrids measured following S 1 -nuclease treatment. FUra produced a concentration-dependent increase in nascent nuclear DHFR-mRNA levels, and a decrease in nascent cytoplasmic DHFR-mRNAs levels. These results suggest that FUra produces either an inhibition of mRNA processing, or an inhibition of nuclear-cytoplasmic transport. Preliminary experiments to examine ATP-dependent mRNA transport were completed with isolated nuclei from cells treated with FUra for 1 or 24 hr and then pulse-labeled for 1 hr with [ 3 H] cytidine. The results demonstrate a FUra-concentration and time-dependent inhibition of ATP-mediated mRNA efflux

  1. Mapping protein-RNA interactions by RCAP, RNA-cross-linking and peptide fingerprinting.

    Science.gov (United States)

    Vaughan, Robert C; Kao, C Cheng

    2015-01-01

    RNA nanotechnology often feature protein RNA complexes. The interaction between proteins and large RNAs are difficult to study using traditional structure-based methods like NMR or X-ray crystallography. RCAP, an approach that uses reversible-cross-linking affinity purification method coupled with mass spectrometry, has been developed to map regions within proteins that contact RNA. This chapter details how RCAP is applied to map protein-RNA contacts within virions.

  2. Discovering drugs for the treatment of Ebola virus

    Science.gov (United States)

    2017-08-04

    in a lipid envelope. The negative-sense single- stranded RNA genome is approximately 19kb in size, and consists of a linear, non-segmented RNA. The...to treat vascular leak syndrome, was administered to patient during the outbreak in an effort to stem vascular leakage [27]. In vitro efficacy

  3. Overview of methods in RNA nanotechnology: synthesis, purification, and characterization of RNA nanoparticles.

    Science.gov (United States)

    Haque, Farzin; Guo, Peixuan

    2015-01-01

    RNA nanotechnology encompasses the use of RNA as a construction material to build homogeneous nanostructures by bottom-up self-assembly with defined size, structure, and stoichiometry; this pioneering concept demonstrated in 1998 (Guo et al., Molecular Cell 2:149-155, 1998; featured in Cell) has emerged as a new field that also involves materials engineering and synthetic structural biology (Guo, Nature Nanotechnology 5:833-842, 2010). The field of RNA nanotechnology has skyrocketed over the last few years, as evidenced by the burst of publications in prominent journals on RNA nanostructures and their applications in nanomedicine and nanotechnology. Rapid advances in RNA chemistry, RNA biophysics, and RNA biology have created new opportunities for translating basic science into clinical practice. RNA nanotechnology holds considerable promise in this regard. Increased evidence also suggests that substantial part of the 98.5 % of human genome (Lander et al. Nature 409:860-921, 2001) that used to be called "junk DNA" actually codes for noncoding RNA. As we understand more on how RNA structures are related to function, we can fabricate synthetic RNA nanoparticles for the diagnosis and treatment of diseases. This chapter provides a brief overview of the field regarding the design, construction, purification, and characterization of RNA nanoparticles for diverse applications in nanotechnology and nanomedicince.

  4. Methylated nucleosides in tRNA and tRNA methyltransferases

    Directory of Open Access Journals (Sweden)

    Hiroyuki eHori

    2014-05-01

    Full Text Available To date, more than 90 modified nucleosides have been found in tRNA and the biosynthetic pathways of the majority of tRNA modifications include a methylation step(s. Recent studies of the biosynthetic pathways have demonstrated that the availability of methyl group donors for the methylation in tRNA is important for correct and efficient protein synthesis. In this review, I focus on the methylated nucleosides and tRNA methyltransferases. The primary functions of tRNA methylations are linked to the different steps of protein synthesis, such as the stabilization of tRNA structure, reinforcement of the codon–anticodon interaction, regulation of wobble base pairing, and prevention of frameshift errors. However, beyond these basic functions, recent studies have demonstrated that tRNA methylations are also involved in the RNA quality control system and regulation of tRNA localization in the cell. In a thermophilic eubacterium, tRNA modifications and the modification enzymes form a network that responses to temperature changes. Furthermore, several modifications are involved in genetic diseases, infections, and the immune response. Moreover, structural, biochemical, and bioinformatics studies of tRNA methyltransferases have been clarifying the details of tRNA methyltransferases and have enabled these enzymes to be classified. In the final section, the evolution of modification enzymes is discussed.

  5. Mutant allele of rna14 in fission yeast affects pre-mRNA splicing

    Indian Academy of Sciences (India)

    transcript. Rna14 protein in budding yeast has been implicated in cleavage and ... Subsequently, genetic interaction of Rna14 with prp1 and physical .... molecular yeast techniques as described by Moreno et al. ..... To elucidate the role of Rna14 in splicing, RT-PCR analysis ..... design principles of a dynamic RNP machine.

  6. Signatures of RNA binding proteins globally coupled to effective microRNA target sites

    DEFF Research Database (Denmark)

    Jacobsen, Anders; Wen, Jiayu; Marks, Debora S

    2010-01-01

    MicroRNAs (miRNAs) and small interfering RNAs (siRNAs), bound to Argonaute proteins (RISC), destabilize mRNAs through base-pairing with the mRNA. However, the gene expression changes after perturbations of these small RNAs are only partially explained by predicted miRNA/siRNA targeting. Targeting...

  7. RNA trafficking in parasitic plant systems

    Science.gov (United States)

    LeBlanc, Megan; Kim, Gunjune; Westwood, James H.

    2012-01-01

    RNA trafficking in plants contributes to local and long-distance coordination of plant development and response to the environment. However, investigations of mobile RNA identity and function are hindered by the inherent difficulty of tracing a given molecule of RNA from its cell of origin to its destination. Several methods have been used to address this problem, but all are limited to some extent by constraints associated with accurately sampling phloem sap or detecting trafficked RNA. Certain parasitic plant species form symplastic connections to their hosts and thereby provide an additional system for studying RNA trafficking. The haustorial connections of Cuscuta and Phelipanche species are similar to graft junctions in that they are able to transmit mRNAs, viral RNAs, siRNAs, and proteins from the host plants to the parasite. In contrast to other graft systems, these parasites form connections with host species that span a wide phylogenetic range, such that a high degree of nucleotide sequence divergence may exist between host and parasites and allow confident identification of most host RNAs in the parasite system. The ability to identify host RNAs in parasites, and vice versa, will facilitate genomics approaches to understanding RNA trafficking. This review discusses the nature of host–parasite connections and the potential significance of host RNAs for the parasite. Additional research on host–parasite interactions is needed to interpret results of RNA trafficking studies, but parasitic plants may provide a fascinating new perspective on RNA trafficking. PMID:22936942

  8. RNA Encapsidation and Packaging in the Phleboviruses

    Directory of Open Access Journals (Sweden)

    Katherine E. Hornak

    2016-07-01

    Full Text Available The Bunyaviridae represents the largest family of segmented RNA viruses, which infect a staggering diversity of plants, animals, and insects. Within the family Bunyaviridae, the Phlebovirus genus includes several important human and animal pathogens, including Rift Valley fever virus (RVFV, severe fever with thrombocytopenia syndrome virus (SFTSV, Uukuniemi virus (UUKV, and the sandfly fever viruses. The phleboviruses have small tripartite RNA genomes that encode a repertoire of 5–7 proteins. These few proteins accomplish the daunting task of recognizing and specifically packaging a tri-segment complement of viral genomic RNA in the midst of an abundance of host components. The critical nucleation events that eventually lead to virion production begin early on in the host cytoplasm as the first strands of nascent viral RNA (vRNA are synthesized. The interaction between the vRNA and the viral nucleocapsid (N protein effectively protects and masks the RNA from the host, and also forms the ribonucleoprotein (RNP architecture that mediates downstream interactions and drives virion formation. Although the mechanism by which all three genomic counterparts are selectively co-packaged is not completely understood, we are beginning to understand the hierarchy of interactions that begins with N-RNA packaging and culminates in RNP packaging into new virus particles. In this review we focus on recent progress that highlights the molecular basis of RNA genome packaging in the phleboviruses.

  9. RNA trafficking in parasitic plant systems

    Directory of Open Access Journals (Sweden)

    Megan L LeBlanc

    2012-08-01

    Full Text Available RNA trafficking in plants contributes to local and long-distance coordination of plant development and response to the environment. However, investigations of mobile RNA identity and function are hindered by the inherent difficulty of tracing a given molecule of RNA from its cell of origin to its destination. Several methods have been used to address this problem, but all are limited to some extent by constraints associated with accurately sampling phloem sap or detecting trafficked RNA. Certain parasitic plant species form symplastic connections to their hosts and thereby provide an additional system for studying RNA trafficking. The haustorial connections of Cuscuta and Phelipanche species are similar to graft junctions in that they are able to transmit mRNAs, viral RNAs, siRNAs and proteins from the host plants to the parasite. In contrast to other graft systems, these parasites form connections with host species that span a wide phylogenetic range, such that a high degree of nucleotide sequence divergence may exist between host and parasites and allow confident identification of most host RNAs in the parasite system. The ability to identify host RNAs in parasites, and vice versa, will facilitate genomics approaches to understanding RNA trafficking. This review discusses the nature of host parasite connections and the potential significance of host RNAs for the parasite. Additional research on host-parasite interactions is needed to interpret results of RNA trafficking studies, but parasitic plants may provide a fascinating new perspective on RNA trafficking.

  10. Customization of Artificial MicroRNA Design.

    Science.gov (United States)

    Van Vu, Tien; Do, Vinh Nang

    2017-01-01

    RNAi approaches, including microRNA (miRNA) regulatory pathway, offer great tools for functional characterization of unknown genes. Moreover, the applications of artificial microRNA (amiRNA) in the field of plant transgenesis have also been advanced to engineer pathogen-resistant or trait-improved transgenic plants. Until now, despite the high potency of amiRNA approach, no commercial plant cultivar expressing amiRNAs with improved traits has been released yet. Beside the issues of biosafety policies, the specificity and efficacy of amiRNAs are of major concerns. Sufficient cares should be taken for the specificity and efficacy of amiRNAs due to their potential off-target effects and other issues relating to in vivo expression of pre-amiRNAs. For these reasons, the proper design of amiRNAs with the lowest off-target possibility is very important for successful applications of the approach in plant. Therefore, there are many studies with the aim to improve the amiRNA design and amiRNA expressing backbones for obtaining better specificity and efficacy. However, the requirement for an efficient reference for the design is still needed. In the present chapter, we attempt to summarize and discuss all the major concerns relating to amiRNA design with the hope to provide a significant guideline for this approach.

  11. Messenger RNA surveillance: neutralizing natural nonsense

    DEFF Research Database (Denmark)

    Weischelfeldt, Joachim Lütken; Lykke-Andersen, Jens; Porse, Bo

    2005-01-01

    Messenger RNA transcripts that contain premature stop codons are degraded by a process termed nonsense-mediated mRNA decay (NMD). Although previously thought of as a pathway that rids the cell of non-functional mRNAs arising from mutations and processing errors, new research suggests a more general...

  12. RNA-based therapies for genodermatoses

    NARCIS (Netherlands)

    Bornert, Olivier; Peking, Patricia; Bremer, Jeroen; Koller, Ulrich; van den Akker, Peter C.; Aartsma-Rus, Annemieke; Pasmooij, Anna M. G.; Murauer, Eva M.; Nystroem, Alexander

    Genetic disorders affecting the skin, genodermatoses, constitute a large and heterogeneous group of diseases, for which treatment is generally limited to management of symptoms. RNA-based therapies are emerging as a powerful tool to treat genodermatoses. In this review, we discuss in detail RNA

  13. ADAR RNA editing below the backbone.

    Science.gov (United States)

    Keegan, Liam; Khan, Anzer; Vukic, Dragana; O'Connell, Mary

    2017-09-01

    ADAR RNA editing enzymes ( a denosine d e a minases acting on R NA) that convert adenosine bases to inosines were first identified biochemically 30 years ago. Since then, studies on ADARs in genetic model organisms, and evolutionary comparisons between them, continue to reveal a surprising range of pleiotropic biological effects of ADARs. This review focuses on Drosophila melanogaster , which has a single Adar gene encoding a homolog of vertebrate ADAR2 that site-specifically edits hundreds of transcripts to change individual codons in ion channel subunits and membrane and cytoskeletal proteins. Drosophila ADAR is involved in the control of neuronal excitability and neurodegeneration and, intriguingly, in the control of neuronal plasticity and sleep. Drosophila ADAR also interacts strongly with RNA interference, a key antiviral defense mechanism in invertebrates. Recent crystal structures of human ADAR2 deaminase domain-RNA complexes help to interpret available information on Drosophila ADAR isoforms and on the evolution of ADARs from tRNA deaminase ADAT proteins. ADAR RNA editing is a paradigm for the now rapidly expanding range of RNA modifications in mRNAs and ncRNAs. Even with recent progress, much remains to be understood about these groundbreaking ADAR RNA modification systems. © 2017 Keegan et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  14. Non-coding RNA in Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Chen Zhongzhong; Wang Liangyan; Lin Jun; Tian Bing; Hua Yuejin

    2006-01-01

    Researches on DNA damage and repair pathways of Deinococcus radiodurans show its extreme resistance to ionizing radiation, ultraviolet radiation and reactive oxygen species. Non-coding (ncRNA) RNAs are involved in a variety of processes such as transcriptional regulations, RNA processing and modification, mRNA translation, protein transportation and stability. The conserved secondary structures of intergenic regions of Deinococcus radiodurans R1 were predicted using Stochastic Context Free Grammar (SCFG) scan strategy. Results showed that 28 ncRNA families were present in the non-coding regions of the genome of Deinococcus radiodurans R1. Among these families, IRE is the largest family, followed by Histone3, tRNA, SECIS. DicF, ctRNA-pGA1 and tmRNA are one discovered in bacteria. Results from the comparison with other organisms showed that these ncRNA can be applied to the study of biological function of Deinococcus radiodurans and supply reference for the further study of DNA damage and repair mechanisms of this bacterium. (authors)

  15. Retroviral RNA Dimerization: From Structure to Functions

    Directory of Open Access Journals (Sweden)

    Noé Dubois

    2018-03-01

    Full Text Available The genome of the retroviruses is a dimer composed by two homologous copies of genomic RNA (gRNA molecules of positive polarity. The dimerization process allows two gRNA molecules to be non-covalently linked together through intermolecular base-pairing. This step is critical for the viral life cycle and is highly conserved among retroviruses with the exception of spumaretroviruses. Furthermore, packaging of two gRNA copies into viral particles presents an important evolutionary advantage for immune system evasion and drug resistance. Recent studies reported RNA switches models regulating not only gRNA dimerization, but also translation and packaging, and a spatio-temporal characterization of viral gRNA dimerization within cells are now at hand. This review summarizes our current understanding on the structural features of the dimerization signals for a variety of retroviruses (HIVs, MLV, RSV, BLV, MMTV, MPMV…, the mechanisms of RNA dimer formation and functional implications in the retroviral cycle.

  16. The integrated analysis of RNA-seq and microRNA-seq depicts miRNA-mRNA networks involved in Japanese flounder (Paralichthys olivaceus) albinism.

    Science.gov (United States)

    Wang, Na; Wang, Ruoqing; Wang, Renkai; Tian, Yongsheng; Shao, Changwei; Jia, Xiaodong; Chen, Songlin

    2017-01-01

    Albinism, a phenomenon characterized by pigmentation deficiency on the ocular side of Japanese flounder (Paralichthys olivaceus), has caused significant damage. Limited mRNA and microRNA (miRNA) information is available on fish pigmentation deficiency. In this study, a high-throughput sequencing strategy was employed to identify the mRNA and miRNAs involved in P. olivaceus albinism. Based on P. olivaceus genome, RNA-seq identified 21,787 know genes and 711 new genes by transcripts assembly. Of those, 235 genes exhibited significantly different expression pattern (fold change ≥2 or ≤0.5 and q-value≤0.05), including 194 down-regulated genes and 41 up-regulated genes in albino versus normally pigmented individuals. These genes were enriched to 81 GO terms and 9 KEGG pathways (p≤0.05). Among those, the pigmentation related pathways-Melanogenesis and tyrosine metabolism were contained. High-throughput miRNA sequencing identified a total of 475 miRNAs, including 64 novel miRNAs. Furthermore, 33 differentially expressed miRNAs containing 13 up-regulated and 20 down-regulated miRNAs were identified in albino versus normally pigmented individuals (fold change ≥1.5 or ≤0.67 and p≤0.05). The next target prediction discovered a variety of putative target genes, of which, 134 genes including Tyrosinase (TYR), Tyrosinase-related protein 1 (TYRP1), Microphthalmia-associated transcription factor (MITF) were overlapped with differentially expressed genes derived from RNA-seq. These target genes were significantly enriched to 254 GO terms and 103 KEGG pathways (p<0.001). Of those, tyrosine metabolism, lysosomes, phototransduction pathways, etc., attracted considerable attention due to their involvement in regulating skin pigmentation. Expression patterns of differentially expressed mRNA and miRNAs were validated in 10 mRNA and 10 miRNAs by qRT-PCR. With high-throughput mRNA and miRNA sequencing and analysis, a series of interested mRNA and miRNAs involved in fish

  17. Long noncoding RNA in hematopoiesis and immunity.

    Science.gov (United States)

    Satpathy, Ansuman T; Chang, Howard Y

    2015-05-19

    Dynamic gene expression during cellular differentiation is tightly coordinated by transcriptional and post-transcriptional mechanisms. An emerging theme is the central role of long noncoding RNAs (lncRNAs) in the regulation of this specificity. Recent advances demonstrate that lncRNAs are expressed in a lineage-specific manner and control the development of several cell types in the hematopoietic system. Moreover, specific lncRNAs are induced to modulate innate and adaptive immune responses. lncRNAs can function via RNA-DNA, RNA-RNA, and RNA-protein target interactions. As a result, they affect several stages of gene regulation, including chromatin modification, mRNA biogenesis, and protein signaling. We discuss recent advances, future prospects, and challenges in understanding the roles of lncRNAs in immunity and immune-mediated diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. A probabilistic model of RNA conformational space

    DEFF Research Database (Denmark)

    Frellsen, Jes; Moltke, Ida; Thiim, Martin

    2009-01-01

    , the discrete nature of the fragments necessitates the use of carefully tuned, unphysical energy functions, and their non-probabilistic nature impairs unbiased sampling. We offer a solution to the sampling problem that removes these important limitations: a probabilistic model of RNA structure that allows...... conformations for 9 out of 10 test structures, solely using coarse-grained base-pairing information. In conclusion, the method provides a theoretical and practical solution for a major bottleneck on the way to routine prediction and simulation of RNA structure and dynamics in atomic detail.......The increasing importance of non-coding RNA in biology and medicine has led to a growing interest in the problem of RNA 3-D structure prediction. As is the case for proteins, RNA 3-D structure prediction methods require two key ingredients: an accurate energy function and a conformational sampling...

  19. Eukaryotic 5S rRNA biogenesis

    Science.gov (United States)

    Ciganda, Martin; Williams, Noreen

    2012-01-01

    The ribosome is a large complex containing both protein and RNA which must be assembled in a precise manner to allow proper functioning in the critical role of protein synthesis. 5S rRNA is the smallest of the RNA components of the ribosome, and although it has been studied for decades, we still do not have a clear understanding of its function within the complex ribosome machine. It is the only RNA species that binds ribosomal proteins prior to its assembly into the ribosome. Its transport into the nucleolus requires this interaction. Here we present an overview of some of the key findings concerning the structure and function of 5S rRNA and how its association with specific proteins impacts its localization and function. PMID:21957041

  20. RNA as a small molecule druggable target.

    Science.gov (United States)

    Rizvi, Noreen F; Smith, Graham F

    2017-12-01

    Small molecule drugs have readily been developed against many proteins in the human proteome, but RNA has remained an elusive target for drug discovery. Increasingly, we see that RNA, and to a lesser extent DNA elements, show a persistent tertiary structure responsible for many diverse and complex cellular functions. In this digest, we have summarized recent advances in screening approaches for RNA targets and outlined the discovery of novel, drug-like small molecules against RNA targets from various classes and therapeutic areas. The link of structure, function, and small-molecule Druggability validates now for the first time that RNA can be the targets of therapeutic agents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. MicroRNA Implication in Cancer

    Directory of Open Access Journals (Sweden)

    Iker BADIOLA

    2010-03-01

    Full Text Available MicroRNAs (miRNA are a new class of posttranscriptional regulators. These small non-coding RNAs regulate the expression of target mRNA transcripts and are linked to several human disease such as Alzheimer, cancer or heart disease. But it has been the cancer disease which has experimented the major number of studies of miRNA linked to the disease progression. In the last years it has been reported the deregulation pattern of the miRNAs in malignant cells which have disrupted the control of the proliferation, differentiation or apoptosis. The evidence of the presence of specific miRNA deregulated in concrete cancer types has become the miRNAs like possible biomarkers and therapeutic targets. The specific miRNA patterns deregulated in concrete cancer cell types open new opportunities to the diagnosis and therapy.

  2. Transfer RNA methylases in rat placenta

    International Nuclear Information System (INIS)

    Jagtiani, S.K.; Narurkar, L.M.; Narurkar, M.V.

    1977-01-01

    Presence of tRNA methylases (5-adenosylmethionine : tRNA methyltransferases) was demonstrated at various stages of gestation in rat placenta, the enzyme being 50-100% higher than that of adult rat liver during early gestation. Placental tRNA methylases were shown to differ from those of liver in the extent of methylation. Glycine methyltransferase (S-adenosylmethionine : glycine methyltransferase), a regulatory enzyme in adult rat liver, was absent in placenta throughout gestation. The placental tRNA methylases could be inhibited in vitro by semipurified glycine methyltransferase from adult rat liver. The high placental tRNA methylase activity was comparable with the inhibitor-free enzyme activity of the adult rat liver. S-adenosyl-[Me- 14 C]-methionine was used in the investigation. (author)

  3. Identifying and characterizing Hfq-RNA interactions.

    Science.gov (United States)

    Faner, M A; Feig, A L

    2013-09-15

    To regulate stress responses and virulence, bacteria use small regulatory RNAs (sRNAs). These RNAs can up or down regulate target mRNAs through base pairing by influencing ribosomal access and RNA decay. A large class of these sRNAs, called trans-encoded sRNAs, requires the RNA binding protein Hfq to facilitate base pairing between the regulatory RNA and its target mRNA. The resulting network of regulation is best characterized in Escherichia coli and Salmonella typhimurium, but the importance of Hfq dependent sRNA regulation is recognized in a diverse population of bacteria. In this review we present the approaches and methods used to discover Hfq binding RNAs, characterize their interactions and elucidate their functions. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Analysis of RNA binding by the dengue virus NS5 RNA capping enzyme.

    Directory of Open Access Journals (Sweden)

    Brittney R Henderson

    Full Text Available Flaviviruses are small, capped positive sense RNA viruses that replicate in the cytoplasm of infected cells. Dengue virus and other related flaviviruses have evolved RNA capping enzymes to form the viral RNA cap structure that protects the viral genome and directs efficient viral polyprotein translation. The N-terminal domain of NS5 possesses the methyltransferase and guanylyltransferase activities necessary for forming mature RNA cap structures. The mechanism for flavivirus guanylyltransferase activity is currently unknown, and how the capping enzyme binds its diphosphorylated RNA substrate is important for deciphering how the flavivirus guanylyltransferase functions. In this report we examine how flavivirus NS5 N-terminal capping enzymes bind to the 5' end of the viral RNA using a fluorescence polarization-based RNA binding assay. We observed that the K(D for RNA binding is approximately 200 nM Dengue, Yellow Fever, and West Nile virus capping enzymes. Removal of one or both of the 5' phosphates reduces binding affinity, indicating that the terminal phosphates contribute significantly to binding. RNA binding affinity is negatively affected by the presence of GTP or ATP and positively affected by S-adensyl methoninine (SAM. Structural superpositioning of the dengue virus capping enzyme with the Vaccinia virus VP39 protein bound to RNA suggests how the flavivirus capping enzyme may bind RNA, and mutagenesis analysis of residues in the putative RNA binding site demonstrate that several basic residues are critical for RNA binding. Several mutants show differential binding to 5' di-, mono-, and un-phosphorylated RNAs. The mode of RNA binding appears similar to that found with other methyltransferase enzymes, and a discussion of diphosphorylated RNA binding is presented.

  5. Four RNA families with functional transient structures.

    Science.gov (United States)

    Zhu, Jing Yun A; Meyer, Irmtraud M

    2015-01-01

    Protein-coding and non-coding RNA transcripts perform a wide variety of cellular functions in diverse organisms. Several of their functional roles are expressed and modulated via RNA structure. A given transcript, however, can have more than a single functional RNA structure throughout its life, a fact which has been previously overlooked. Transient RNA structures, for example, are only present during specific time intervals and cellular conditions. We here introduce four RNA families with transient RNA structures that play distinct and diverse functional roles. Moreover, we show that these transient RNA structures are structurally well-defined and evolutionarily conserved. Since Rfam annotates one structure for each family, there is either no annotation for these transient structures or no such family. Thus, our alignments either significantly update and extend the existing Rfam families or introduce a new RNA family to Rfam. For each of the four RNA families, we compile a multiple-sequence alignment based on experimentally verified transient and dominant (dominant in terms of either the thermodynamic stability and/or attention received so far) RNA secondary structures using a combination of automated search via covariance model and manual curation. The first alignment is the Trp operon leader which regulates the operon transcription in response to tryptophan abundance through alternative structures. The second alignment is the HDV ribozyme which we extend to the 5' flanking sequence. This flanking sequence is involved in the regulation of the transcript's self-cleavage activity. The third alignment is the 5' UTR of the maturation protein from Levivirus which contains a transient structure that temporarily postpones the formation of the final inhibitory structure to allow translation of maturation protein. The fourth and last alignment is the SAM riboswitch which regulates the downstream gene expression by assuming alternative structures upon binding of SAM. All

  6. RNA processing and ribonucleoprotein assembly studied in vivo by RNA transfection

    International Nuclear Information System (INIS)

    Kleinschmidt, A.M.; Pederson, T.

    1990-01-01

    The authors present a method for studying RNA processing and ribonucleoprotein assembly in vivo, by using RNA synthesized in vitro. SP6-transcribed 32 P-labeled U2 small nuclear RNA precursor molecules were introduced into cultured human 293 cells by calcium phosphate-mediated uptake, as in standard DNA transfection experiments. RNase protection mapping demonstrated that the introduced pre-U2 RNA underwent accurate 3' end processing. The introduced U2 RNA was assembled into ribonucleoprotein particles that reacted with an antibody specific for proteins known to be associated with the U2 small nuclear ribonucleoprotein particle. The 3' end-processed, ribonucleoprotein-assembled U2 RNA accumulated in the nuclear fraction. When pre-U2 RNA with a 7-methylguanosine group at the 5' end was introduced into cells, it underwent conversion to a 2,2,7-trimethylguanosine cap structure, a characteristic feature of the U-small nuclear RNAs. Pre-U2 RNA introduced with an adenosine cap (Ap-ppG) also underwent processing, small nuclear ribonucleoprotein assembly, and nuclear accumulation, establishing that a methylated guanosine cap structure is not required for these steps in U2 small nuclear ribonucleprotein biosynthesis. Beyond its demonstrated usefulness in the study of small nuclear ribonucleoprotein biosynthesis, RNA transfection may be of general applicability to the investigation of eukaryotic RNA processing in vivo and may also offer opportunities for introducing therapeutically targeted RNAs (ribozymes or antisense RNA) into cells

  7. MicroRNA-target binding structures mimic microRNA duplex structures in humans.

    Directory of Open Access Journals (Sweden)

    Xi Chen

    Full Text Available Traditionally, researchers match a microRNA guide strand to mRNA sequences using sequence comparisons to predict its potential target genes. However, many of the predictions can be false positives due to limitations in sequence comparison alone. In this work, we consider the association of two related RNA structures that share a common guide strand: the microRNA duplex and the microRNA-target binding structure. We have analyzed thousands of such structure pairs and found many of them share high structural similarity. Therefore, we conclude that when predicting microRNA target genes, considering just the microRNA guide strand matches to gene sequences may not be sufficient--the microRNA duplex structure formed by the guide strand and its companion passenger strand must also be considered. We have developed software to translate RNA binding structure into encoded representations, and we have also created novel automatic comparison methods utilizing such encoded representations to determine RNA structure similarity. Our software and methods can be utilized in the other RNA secondary structure comparisons as well.

  8. Conformational Selection and Induced Fit for RNA Polymerase and RNA/DNA Hybrid Backtracked Recognition

    Directory of Open Access Journals (Sweden)

    Haifeng eChen

    2015-11-01

    Full Text Available RNA polymerase catalyzes transcription with a high fidelity. If DNA/RNA mismatch or DNA damage occurs downstream, a backtracked RNA polymerase can proofread this situation. However, the backtracked mechanism is still poorly understood. Here we have performed multiple explicit-solvent molecular dynamics (MD simulations on bound and apo DNA/RNA hybrid to study backtracked recognition. MD simulations at room temperature suggest that specific electrostatic interactions play key roles in the backtracked recognition between the polymerase and DNA/RNA hybrid. Kinetics analysis at high temperature shows that bound and apo DNA/RNA hybrid unfold via a two-state process. Both kinetics and free energy landscape analyses indicate that bound DNA/RNA hybrid folds in the order of DNA/RNA contracting, the tertiary folding and polymerase binding. The predicted Φ-values suggest that C7, G9, dC12, dC15 and dT16 are key bases for the backtracked recognition of DNA/RNA hybrid. The average RMSD values between the bound structures and the corresponding apo ones and Kolmogorov-Smirnov (KS P test analyses indicate that the recognition between DNA/RNA hybrid and polymerase might follow an induced fit mechanism for DNA/RNA hybrid and conformation selection for polymerase. Furthermore, this method could be used to relative studies of specific recognition between nucleic acid and protein.

  9. Phloem RNA-binding proteins as potential components of the long-distance RNA transport system.

    Directory of Open Access Journals (Sweden)

    VICENTE ePALLAS

    2013-05-01

    Full Text Available RNA-binding proteins (RBPs govern a myriad of different essential processes in eukaryotic cells. Recent evidence reveals that apart from playing critical roles in RNA metabolism and RNA transport, RBPs perform a key function in plant adaption to various environmental conditions. Long distance RNA transport occurs in land plants through the phloem, a conducting tissue that integrates the wide range of signalling pathways required to regulate plant development and response to stress processes. The macromolecules in the phloem pathway vary greatly and include defence proteins, transcription factors, chaperones acting in long distance trafficking, and RNAs (mRNAs, siRNAs and miRNAs. How these RNA molecules translocate through the phloem is not well understood, but recent evidence indicates the presence of translocatable RNA-binding proteins in the phloem, which act as potential components of long distance RNA transport system. This review updates our knowledge on the characteristics and functions of RBPs present in the phloem.

  10. Recoding aminoacyl-tRNA synthetases for synthetic biology by rational protein-RNA engineering.

    Science.gov (United States)

    Hadd, Andrew; Perona, John J

    2014-12-19

    We have taken a rational approach to redesigning the amino acid binding and aminoacyl-tRNA pairing specificities of bacterial glutaminyl-tRNA synthetase. The four-stage engineering incorporates generalizable design principles and improves the pairing efficiency of noncognate glutamate with tRNA(Gln) by over 10(5)-fold compared to the wild-type enzyme. Better optimized designs of the protein-RNA complex include substantial reengineering of the globular core region of the tRNA, demonstrating a role for specific tRNA nucleotides in specifying the identity of the genetically encoded amino acid. Principles emerging from this engineering effort open new prospects for combining rational and genetic selection approaches to design novel aminoacyl-tRNA synthetases that ligate noncanonical amino acids onto tRNAs. This will facilitate reconstruction of the cellular translation apparatus for applications in synthetic biology.

  11. Cap-independent translation mechanism of red clover necrotic mosaic virus RNA2 differs from that of RNA1 and is linked to RNA replication.

    Science.gov (United States)

    Mizumoto, Hiroyuki; Iwakawa, Hiro-Oki; Kaido, Masanori; Mise, Kazuyuki; Okuno, Tetsuro

    2006-04-01

    The genome of Red clover necrotic mosaic virus (RCNMV) in the genus Dianthovirus is divided into two RNA molecules of RNA1 and RNA2, which have no cap structure at the 5' end and no poly(A) tail at the 3' end. The 3' untranslated region (3' UTR) of RCNMV RNA1 contains an essential RNA element (3'TE-DR1), which is required for cap-independent translation. In this study, we investigated a cap-independent translational mechanism of RNA2 using a firefly luciferase (Luc) gene expression assay system in cowpea protoplasts and a cell-free lysate (BYL) prepared from evacuolated tobacco BY2 protoplasts. We were unable to detect cis-acting RNA sequences in RNA2 that can replace the function of a cap structure, such as the 3'TE-DR1 of RNA1. However, the uncapped reporter RNA2, RNA2-Luc, in which the Luc open reading frame (ORF) was inserted between the 5' UTR and the movement protein ORF, was effectively translated in the presence of p27 and p88 in protoplasts in which RNA2-Luc was replicated. Time course experiments in protoplasts showed that the translational activity of RNA2-Luc did not reflect the amount of RNA2. Mutations in cis-acting RNA replication elements of RNA2 abolished the cap-independent translational activity of RNA2-Luc, suggesting that the translational activity of RNA2-Luc is coupled to RNA replication. Our results show that the translational mechanism differs between two segmented genomic RNAs of RCNMV. We present a model in which only RNA2 that is generated de novo through the viral RNA replication machinery functions as mRNA for translation.

  12. Combining miRNA and mRNA Expression Profiles in Wilms Tumor Subtypes

    Directory of Open Access Journals (Sweden)

    Nicole Ludwig

    2016-03-01

    Full Text Available Wilms tumor (WT is the most common childhood renal cancer. Recent findings of mutations in microRNA (miRNA processing proteins suggest a pivotal role of miRNAs in WT genesis. We performed miRNA expression profiling of 36 WTs of different subtypes and four normal kidney tissues using microarrays. Additionally, we determined the gene expression profile of 28 of these tumors to identify potentially correlated target genes and affected pathways. We identified 85 miRNAs and 2107 messenger RNAs (mRNA differentially expressed in blastemal WT, and 266 miRNAs and 1267 mRNAs differentially expressed in regressive subtype. The hierarchical clustering of the samples, using either the miRNA or mRNA profile, showed the clear separation of WT from normal kidney samples, but the miRNA pattern yielded better separation of WT subtypes. A correlation analysis of the deregulated miRNA and mRNAs identified 13,026 miRNA/mRNA pairs with inversely correlated expression, of which 2844 are potential interactions of miRNA and their predicted mRNA targets. We found significant upregulation of miRNAs-183, -301a/b and -335 for the blastemal subtype, and miRNAs-181b, -223 and -630 for the regressive subtype. We found marked deregulation of miRNAs regulating epithelial to mesenchymal transition, especially in the blastemal subtype, and miRNAs influencing chemosensitivity, especially in regressive subtypes. Further research is needed to assess the influence of preoperative chemotherapy and tumor infiltrating lymphocytes on the miRNA and mRNA patterns in WT.

  13. MicroRNA-directed siRNA biogenesis in Caenorhabditis elegans.

    Science.gov (United States)

    Corrêa, Régis L; Steiner, Florian A; Berezikov, Eugene; Ketting, René F

    2010-04-08

    RNA interference (RNAi) is a post-transcriptional silencing process, triggered by double-stranded RNA (dsRNA), leading to the destabilization of homologous mRNAs. A distinction has been made between endogenous RNAi-related pathways and the exogenous RNAi pathway, the latter being essential for the experimental use of RNAi. Previous studies have shown that, in Caenorhabditis elegans, a complex containing the enzymes Dicer and the Argonaute RDE-1 process dsRNA. Dicer is responsible for cleaving dsRNA into short interfering RNAs (siRNAs) while RDE-1 acts as the siRNA acceptor. RDE-1 then guides a multi-protein complex to homologous targets to trigger mRNA destabilization. However, endogenous role(s) for RDE-1, if any, have remained unexplored. We here show that RDE-1 functions as a scavenger protein, taking up small RNA molecules from many different sources, including the microRNA (miRNA) pathway. This is in striking contrast to Argonaute proteins functioning directly in the miRNA pathway, ALG-1 and ALG-2: these proteins exclusively bind miRNAs. While playing no significant role in the biogenesis of the main pool of miRNAs, RDE-1 binds endogenous miRNAs and triggers RdRP activity on at least one perfectly matching, endogenous miRNA target. The resulting secondary siRNAs are taken up by a set of Argonaute proteins known to act as siRNA acceptors in exogenous RNAi, resulting in strong mRNA destabilization. Our results show that RDE-1 in an endogenous setting is actively screening the transcriptome using many different small RNAs, including miRNAs, as a guide, with implications for the evolution of transcripts with a potential to be recognized by Dicer.

  14. Interactions between the HIV-1 Unspliced mRNA and Host mRNA Decay Machineries

    Directory of Open Access Journals (Sweden)

    Daniela Toro-Ascuy

    2016-11-01

    Full Text Available The human immunodeficiency virus type-1 (HIV-1 unspliced transcript is used both as mRNA for the synthesis of structural proteins and as the packaged genome. Given the presence of retained introns and instability AU-rich sequences, this viral transcript is normally retained and degraded in the nucleus of host cells unless the viral protein REV is present. As such, the stability of the HIV-1 unspliced mRNA must be particularly controlled in the nucleus and the cytoplasm in order to ensure proper levels of this viral mRNA for translation and viral particle formation. During its journey, the HIV-1 unspliced mRNA assembles into highly specific messenger ribonucleoproteins (mRNPs containing many different host proteins, amongst which are well-known regulators of cytoplasmic mRNA decay pathways such as up-frameshift suppressor 1 homolog (UPF1, Staufen double-stranded RNA binding protein 1/2 (STAU1/2, or components of miRNA-induced silencing complex (miRISC and processing bodies (PBs. More recently, the HIV-1 unspliced mRNA was shown to contain N6-methyladenosine (m6A, allowing the recruitment of YTH N6-methyladenosine RNA binding protein 2 (YTHDF2, an m6A reader host protein involved in mRNA decay. Interestingly, these host proteins involved in mRNA decay were shown to play positive roles in viral gene expression and viral particle assembly, suggesting that HIV-1 interacts with mRNA decay components to successfully accomplish viral replication. This review summarizes the state of the art in terms of the interactions between HIV-1 unspliced mRNA and components of different host mRNA decay machineries.

  15. Intranasal delivery of antiviral siRNA.

    Science.gov (United States)

    Barik, Sailen

    2011-01-01

    Intranasal administration of synthetic siRNA is an effective modality of RNAi delivery for the prevention and therapy of respiratory diseases, including pulmonary infections. Vehicles used for nasal siRNA delivery include established as well as novel reagents, many of which have been recently optimized. In general, they all promote significant uptake of siRNA into the lower respiratory tract, including the lung. When properly designed and optimized, these siRNAs offer significant protection against respiratory viruses such as influenza virus, parainfluenza virus and respiratory syncytial virus (RSV). Nasally administered siRNA remains within the lung and does not access systemic blood flow, as judged by its absence in other major organs such as liver, heart, kidney, and skeletal muscle. Adverse immune reaction is generally not encountered, especially when immunogenic and/or off-target siRNA sequences and toxic vehicles are avoided. In fact, siRNA against RSV has entered Phase II clinical trials in human with promising results. Here, we provide a standardized procedure for using the nose as a specific route for siRNA delivery into the lung of laboratory animals. It should be clear that this simple and efficient system has enormous potential for therapeutics.

  16. The cellular receptors of exogenous RNA

    Directory of Open Access Journals (Sweden)

    Patryk Reniewicz

    2016-04-01

    Full Text Available One of the key determinants of survival for organisms is proper recognition of exogenous and endogenous nucleic acids. Therefore, high eukaryotes developed a number of receptors that allow for discrimination between friend or foe DNA and RNA. Appearance of exogenous RNA in cytoplasm provides a signal of danger and triggers cellular responses that facilitate eradication of a pathogen. Recognition of exogenous RNA is additionally complicated by fact that large amount of endogenous RNA is present in cytoplasm Thus, number of different receptors, found in eukaryotic cells, is able to recognize that nucleic acid. First group of those receptors consist endosomal Toll like receptors, namely TLR3, TLR7, TLR8 and TLR13. Those receptors recognize RNA released from pathogens that enter the cell by endocytosis. The second group includes cytoplasmic sensors like PKR and the family of RLRs comprised of RIG-I, MDA5 and LGP2. Cytoplasmic receptors recognize RNA from pathogens invading the cell by non-endocytic pathway. In both cases binding of RNA by its receptors results in activation of the signalling cascades that lead to the production of interferon and other cytokines.

  17. Annotating RNA motifs in sequences and alignments.

    Science.gov (United States)

    Gardner, Paul P; Eldai, Hisham

    2015-01-01

    RNA performs a diverse array of important functions across all cellular life. These functions include important roles in translation, building translational machinery and maturing messenger RNA. More recent discoveries include the miRNAs and bacterial sRNAs that regulate gene expression, the thermosensors, riboswitches and other cis-regulatory elements that help prokaryotes sense their environment and eukaryotic piRNAs that suppress transposition. However, there can be a long period between the initial discovery of a RNA and determining its function. We present a bioinformatic approach to characterize RNA motifs, which are critical components of many RNA structure-function relationships. These motifs can, in some instances, provide researchers with functional hypotheses for uncharacterized RNAs. Moreover, we introduce a new profile-based database of RNA motifs--RMfam--and illustrate some applications for investigating the evolution and functional characterization of RNA. All the data and scripts associated with this work are available from: https://github.com/ppgardne/RMfam. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  18. RNA interference and Register Machines (extended abstract

    Directory of Open Access Journals (Sweden)

    Masahiro Hamano

    2012-11-01

    Full Text Available RNA interference (RNAi is a mechanism whereby small RNAs (siRNAs directly control gene expression without assistance from proteins. This mechanism consists of interactions between RNAs and small RNAs both of which may be single or double stranded. The target of the mechanism is mRNA to be degraded or aberrated, while the initiator is double stranded RNA (dsRNA to be cleaved into siRNAs. Observing the digital nature of RNAi, we represent RNAi as a Minsky register machine such that (i The two registers hold single and double stranded RNAs respectively, and (ii Machine's instructions are interpreted by interactions of enzyme (Dicer, siRNA (with RISC com- plex and polymerization (RdRp to the appropriate registers. Interpreting RNAi as a computational structure, we can investigate the computational meaning of RNAi, especially its complexity. Initially, the machine is configured as a Chemical Ground Form (CGF, which generates incorrect jumps. To remedy this problem, the system is remodeled as recursive RNAi, in which siRNA targets not only mRNA but also the machine instructional analogues of Dicer and RISC. Finally, probabilistic termination is investigated in the recursive RNAi system.

  19. SRD: a Staphylococcus regulatory RNA database.

    Science.gov (United States)

    Sassi, Mohamed; Augagneur, Yoann; Mauro, Tony; Ivain, Lorraine; Chabelskaya, Svetlana; Hallier, Marc; Sallou, Olivier; Felden, Brice

    2015-05-01

    An overflow of regulatory RNAs (sRNAs) was identified in a wide range of bacteria. We designed and implemented a new resource for the hundreds of sRNAs identified in Staphylococci, with primary focus on the human pathogen Staphylococcus aureus. The "Staphylococcal Regulatory RNA Database" (SRD, http://srd.genouest.org/) compiled all published data in a single interface including genetic locations, sequences and other features. SRD proposes novel and simplified identifiers for Staphylococcal regulatory RNAs (srn) based on the sRNA's genetic location in S. aureus strain N315 which served as a reference. From a set of 894 sequences and after an in-depth cleaning, SRD provides a list of 575 srn exempt of redundant sequences. For each sRNA, their experimental support(s) is provided, allowing the user to individually assess their validity and significance. RNA-seq analysis performed on strains N315, NCTC8325, and Newman allowed us to provide further details, upgrade the initial annotation, and identified 159 RNA-seq independent transcribed sRNAs. The lists of 575 and 159 sRNAs sequences were used to predict the number and location of srns in 18 S. aureus strains and 10 other Staphylococci. A comparison of the srn contents within 32 Staphylococcal genomes revealed a poor conservation between species. In addition, sRNA structure predictions obtained with MFold are accessible. A BLAST server and the intaRNA program, which is dedicated to target prediction, were implemented. SRD is the first sRNA database centered on a genus; it is a user-friendly and scalable device with the possibility to submit new sequences that should spread in the literature. © 2015 Sassi et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  20. Circular RNA (circRNA) was an important bridge in the switch from the RNA world to the DNA world.

    Science.gov (United States)

    Soslau, Gerald

    2018-06-14

    The concept that life on Earth began as an RNA world has been built upon extensive experimentation demonstrating that many of the building blocks required for living cells could be synthesized in the laboratory under conditions approximating our primordial world. Many of the building blocks for life have also been found in meteorites indicating that meteors may have been a source for these molecules, or more likely, that they represent the chemical library present in most/all bodies in the universe after the big bang. Perhaps the most important support for the concept comes from the fact that some RNA species possess catalytic activity, ribozymes, and that RNA could be reverse transcribe to DNA. The thrust of numerous papers on this topic has been to explore how the available molecules on Earth, at its birth, gave rise to life as we know it today. This paper focuses more on a reverse view of the topic. The "how" molecular building blocks were synthesized is not addressed nor how the "first" RNA molecules were synthesized. We can clearly speculate on the variable environmental conditions and chemistry available on Earth billions of years ago. However, we can never truly replicate the changing conditions or know the chemical composition of Earth at the beginning of time. We can, however, confirm that over millions, perhaps billions of years the basic building blocks for life accumulated sufficiently to initiate evolution to an RNA world followed by our RNA/DNA world. Here we are attempting to take the information from our current knowledge of biology and by inference and extrapolation work backward to hypothesize biological events in the march forward from RNA to DNA. It is proposed that the primordial replicating RNA cell, the ribocyte, evolved from liposomes encompassing required reactants and products for "life" and that ribonucleopeptide complexes formed membrane pores to support bidirectional ion and molecular transport to maintain biological functions and

  1. Chemical fidelity of an RNA polymerase ribozyme

    DEFF Research Database (Denmark)

    Attwater, J.; Tagami, S.; Kimoto, M.

    2013-01-01

    for function. Here we have explored the chemical fidelity, i.e. substrate selectivity and specificity for both single and multiple catalytic steps of the Z RNA polymerase ribozyme-a modern day analogue of the primordial RNA replicase. Using a wide range of nucleotide analogues and ionic conditions, we observe......The emergence of catalytically active RNA enzymes (ribozymes) is widely believed to have been an important transition in the origin of life. In the context of a likely heterogeneous chemical environment, substrate specificity and selectivity of these primordial enzymes would have been critical...

  2. Transcriptional Regulation in Ebola Virus: Effects of Gene Border Structure and Regulatory Elements on Gene Expression and Polymerase Scanning Behavior.

    Science.gov (United States)

    Brauburger, Kristina; Boehmann, Yannik; Krähling, Verena; Mühlberger, Elke

    2016-02-15

    The highly pathogenic Ebola virus (EBOV) has a nonsegmented negative-strand (NNS) RNA genome containing seven genes. The viral genes either are separated by intergenic regions (IRs) of variable length or overlap. The structure of the EBOV gene overlaps is conserved throughout all filovirus genomes and is distinct from that of the overlaps found in other NNS RNA viruses. Here, we analyzed how diverse gene borders and noncoding regions surrounding the gene borders influence transcript levels and govern polymerase behavior during viral transcription. Transcription of overlapping genes in EBOV bicistronic minigenomes followed the stop-start mechanism, similar to that followed by IR-containing gene borders. When the gene overlaps were extended, the EBOV polymerase was able to scan the template in an upstream direction. This polymerase feature seems to be generally conserved among NNS RNA virus polymerases. Analysis of IR-containing gene borders showed that the IR sequence plays only a minor role in transcription regulation. Changes in IR length were generally well tolerated, but specific IR lengths led to a strong decrease in downstream gene expression. Correlation analysis revealed that these effects were largely independent of the surrounding gene borders. Each EBOV gene contains exceptionally long untranslated regions (UTRs) flanking the open reading frame. Our data suggest that the UTRs adjacent to the gene borders are the main regulators of transcript levels. A highly complex interplay between the different cis-acting elements to modulate transcription was revealed for specific combinations of IRs and UTRs, emphasizing the importance of the noncoding regions in EBOV gene expression control. Our data extend those from previous analyses investigating the implication of noncoding regions at the EBOV gene borders for gene expression control. We show that EBOV transcription is regulated in a highly complex yet not easily predictable manner by a set of interacting cis

  3. An upstream open reading frame modulates ebola virus polymerase translation and virus replication.

    Directory of Open Access Journals (Sweden)

    Reed S Shabman

    2013-01-01

    Full Text Available Ebolaviruses, highly lethal zoonotic pathogens, possess longer genomes than most other non-segmented negative-strand RNA viruses due in part to long 5' and 3' untranslated regions (UTRs present in the seven viral transcriptional units. To date, specific functions have not been assigned to these UTRs. With reporter assays, we demonstrated that the Zaire ebolavirus (EBOV 5'-UTRs lack internal ribosomal entry site function. However, the 5'-UTRs do differentially regulate cap-dependent translation when placed upstream of a GFP reporter gene. Most dramatically, the 5'-UTR derived from the viral polymerase (L mRNA strongly suppressed translation of GFP compared to a β-actin 5'-UTR. The L 5'-UTR is one of four viral genes to possess upstream AUGs (uAUGs, and ablation of each uAUG enhanced translation of the primary ORF (pORF, most dramatically in the case of the L 5'-UTR. The L uAUG was sufficient to initiate translation, is surrounded by a "weak" Kozak sequence and suppressed pORF translation in a position-dependent manner. Under conditions where eIF2α was phosphorylated, the presence of the uORF maintained translation of the L pORF, indicating that the uORF modulates L translation in response to cellular stress. To directly address the role of the L uAUG in virus replication, a recombinant EBOV was generated in which the L uAUG was mutated to UCG. Strikingly, mutating two nucleotides outside of previously-defined protein coding and cis-acting regulatory sequences attenuated virus growth to titers 10-100-fold lower than a wild-type virus in Vero and A549 cells. The mutant virus also exhibited decreased viral RNA synthesis as early as 6 hours post-infection and enhanced sensitivity to the stress inducer thapsigargin. Cumulatively, these data identify novel mechanisms by which EBOV regulates its polymerase expression, demonstrate their relevance to virus replication and identify a potential therapeutic target.

  4. Exploring complex miRNA-mRNA interactions with Bayesian networks by splitting-averaging strategy

    Directory of Open Access Journals (Sweden)

    Liu Lin

    2009-12-01

    Full Text Available Abstract Background microRNAs (miRNAs regulate target gene expression by controlling their mRNAs post-transcriptionally. Increasing evidence demonstrates that miRNAs play important roles in various biological processes. However, the functions and precise regulatory mechanisms of most miRNAs remain elusive. Current research suggests that miRNA regulatory modules are complicated, including up-, down-, and mix-regulation for different physiological conditions. Previous computational approaches for discovering miRNA-mRNA interactions focus only on down-regulatory modules. In this work, we present a method to capture complex miRNA-mRNA interactions including all regulatory types between miRNAs and mRNAs. Results We present a method to capture complex miRNA-mRNA interactions using Bayesian network structure learning with splitting-averaging strategy. It is designed to explore all possible miRNA-mRNA interactions by integrating miRNA-targeting information, expression profiles of miRNAs and mRNAs, and sample categories. We also present an analysis of data sets for epithelial and mesenchymal transition (EMT. Our results show that the proposed method identified all possible types of miRNA-mRNA interactions from the data. Many interactions are of tremendous biological significance. Some discoveries have been validated by previous research, for example, the miR-200 family negatively regulates ZEB1 and ZEB2 for EMT. Some are consistent with the literature, such as LOX has wide interactions with the miR-200 family members for EMT. Furthermore, many novel interactions are statistically significant and worthy of validation in the near future. Conclusions This paper presents a new method to explore the complex miRNA-mRNA interactions for different physiological conditions using Bayesian network structure learning with splitting-averaging strategy. The method makes use of heterogeneous data including miRNA-targeting information, expression profiles of miRNAs and

  5. Affinity maturation of a portable Fab–RNA module for chaperone-assisted RNA crystallography

    Science.gov (United States)

    Koirala, Deepak; Shelke, Sandip A; Dupont, Marcel; Ruiz, Stormy; DasGupta, Saurja; Bailey, Lucas J; Benner, Steven A; Piccirilli, Joseph A

    2018-01-01

    Abstract Antibody fragments such as Fabs possess properties that can enhance protein and RNA crystallization and therefore can facilitate macromolecular structure determination. In particular, Fab BL3–6 binds to an AAACA RNA pentaloop closed by a GC pair with ∼100 nM affinity. The Fab and hairpin have served as a portable module for RNA crystallization. The potential for general application make it desirable to adjust the properties of this crystallization module in a manner that facilitates its use for RNA structure determination, such as ease of purification, surface entropy or binding affinity. In this work, we used both in vitro RNA selection and phage display selection to alter the epitope and paratope sides of the binding interface, respectively, for improved binding affinity. We identified a 5′-GNGACCC-3′ consensus motif in the RNA and S97N mutation in complimentarity determining region L3 of the Fab that independently impart about an order of magnitude improvement in affinity, resulting from new hydrogen bonding interactions. Using a model RNA, these modifications facilitated crystallization under a wider range of conditions and improved diffraction. The improved features of the Fab–RNA module may facilitate its use as an affinity tag for RNA purification and imaging and as a chaperone for RNA crystallography. PMID:29309709

  6. Spontaneous reverse movement of mRNA-bound tRNA through the ribosome.

    Science.gov (United States)

    Konevega, Andrey L; Fischer, Niels; Semenkov, Yuri P; Stark, Holger; Wintermeyer, Wolfgang; Rodnina, Marina V

    2007-04-01

    During the translocation step of protein synthesis, a complex of two transfer RNAs bound to messenger RNA (tRNA-mRNA) moves through the ribosome. The reaction is promoted by an elongation factor, called EF-G in bacteria, which, powered by GTP hydrolysis, induces an open, unlocked conformation of the ribosome that allows for spontaneous tRNA-mRNA movement. Here we show that, in the absence of EF-G, there is spontaneous backward movement, or retrotranslocation, of two tRNAs bound to mRNA. Retrotranslocation is driven by the gain in affinity when a cognate E-site tRNA moves into the P site, which compensates the affinity loss accompanying the movement of peptidyl-tRNA from the P to the A site. These results lend support to the diffusion model of tRNA movement during translocation. In the cell, tRNA movement is biased in the forward direction by EF-G, which acts as a Brownian ratchet and prevents backward movement.

  7. Thermal Stability of siRNA Modulates Aptamer- conjugated siRNA Inhibition

    Directory of Open Access Journals (Sweden)

    Alexey Berezhnoy

    2012-01-01

    Full Text Available Oligonucleotide aptamer-mediated in vivo cell targeting of small interfering RNAs (siRNAs is emerging as a useful approach to enhance the efficacy and reduce the adverse effects resulting from siRNA-mediated genetic interference. A current main impediment in aptamer-mediated siRNA targeting is that the activity of the siRNA is often compromised when conjugated to an aptamer, often requiring labor intensive and time consuming design and testing of multiple configurations to identify a conjugate in which the siRNA activity has not been significantly reduced. Here, we show that the thermal stability of the siRNA is an important parameter of siRNA activity in its conjugated form, and that siRNAs with lower melting temperature (Tm are not or are minimally affected when conjugated to the 3′ end of 2′F-pyrimidine-modified aptamers. In addition, the configuration of the aptamer-siRNA conjugate retains activity comparable with the free siRNA duplex when the passenger strand is co-transcribed with the aptamer and 3′ overhangs on the passenger strand are removed. The approach described in this paper significantly reduces the time and effort necessary to screening siRNA sequences that retain biological activity upon aptamer conjugation, facilitating the process of identifying candidate aptamer-siRNA conjugates suitable for in vivo testing.

  8. A Method to Predict the Structure and Stability of RNA/RNA Complexes.

    Science.gov (United States)

    Xu, Xiaojun; Chen, Shi-Jie

    2016-01-01

    RNA/RNA interactions are essential for genomic RNA dimerization and regulation of gene expression. Intermolecular loop-loop base pairing is a widespread and functionally important tertiary structure motif in RNA machinery. However, computational prediction of intermolecular loop-loop base pairing is challenged by the entropy and free energy calculation due to the conformational constraint and the intermolecular interactions. In this chapter, we describe a recently developed statistical mechanics-based method for the prediction of RNA/RNA complex structures and stabilities. The method is based on the virtual bond RNA folding model (Vfold). The main emphasis in the method is placed on the evaluation of the entropy and free energy for the loops, especially tertiary kissing loops. The method also uses recursive partition function calculations and two-step screening algorithm for large, complicated structures of RNA/RNA complexes. As case studies, we use the HIV-1 Mal dimer and the siRNA/HIV-1 mutant (T4) to illustrate the method.

  9. Mutations in the RNA-binding domains of tombusvirus replicase proteins affect RNA recombination in vivo

    International Nuclear Information System (INIS)

    Panaviene, Zivile; Nagy, Peter D.

    2003-01-01

    RNA recombination, which is thought to occur due to replicase errors during viral replication, is one of the major driving forces of virus evolution. In this article, we show evidence that the replicase proteins of Cucumber necrosis virus, a tombusvirus, are directly involved in RNA recombination in vivo. Mutations within the RNA-binding domains of the replicase proteins affected the frequency of recombination observed with a prototypical defective-interfering (DI) RNA, a model template for recombination studies. Five of the 17 replicase mutants tested showed delay in the formation of recombinants when compared to the wild-type helper virus. Interestingly, two replicase mutants accelerated recombinant formation and, in addition, these mutants also increased the level of subgenomic RNA synthesis (Virology 308 (2003), 191-205). A trans-complementation system was used to demonstrate that mutation in the p33 replicase protein resulted in altered recombination rate. Isolated recombinants were mostly imprecise (nonhomologous), with the recombination sites clustered around a replication enhancer region and a putative cis-acting element, respectively. These RNA elements might facilitate the proposed template switching events by the tombusvirus replicase. Together with data in the article cited above, results presented here firmly establish that the conserved RNA-binding motif of the replicase proteins is involved in RNA replication, subgenomic RNA synthesis, and RNA recombination

  10. Lysosomal putative RNA transporter SIDT2 mediates direct uptake of RNA by lysosomes.

    Science.gov (United States)

    Aizawa, Shu; Fujiwara, Yuuki; Contu, Viorica Raluca; Hase, Katsunori; Takahashi, Masayuki; Kikuchi, Hisae; Kabuta, Chihana; Wada, Keiji; Kabuta, Tomohiro

    2016-01-01

    Lysosomes are thought to be the major intracellular compartment for the degradation of macromolecules. We recently identified a novel type of autophagy, RNautophagy, where RNA is directly taken up by lysosomes in an ATP-dependent manner and degraded. However, the mechanism of RNA translocation across the lysosomal membrane and the physiological role of RNautophagy remain unclear. In the present study, we performed gain- and loss-of-function studies with isolated lysosomes, and found that SIDT2 (SID1 transmembrane family, member 2), an ortholog of the Caenorhabditis elegans putative RNA transporter SID-1 (systemic RNA interference deficient-1), mediates RNA translocation during RNautophagy. We also observed that SIDT2 is a transmembrane protein, which predominantly localizes to lysosomes. Strikingly, knockdown of Sidt2 inhibited up to ˜50% of total RNA degradation at the cellular level, independently of macroautophagy. Moreover, we showed that this impairment is mainly due to inhibition of lysosomal RNA degradation, strongly suggesting that RNautophagy plays a significant role in constitutive cellular RNA degradation. Our results provide a novel insight into the mechanisms of RNA metabolism, intracellular RNA transport, and atypical types of autophagy.

  11. Lowering the quantification limit of the QubitTM RNA HS assay using RNA spike-in.

    Science.gov (United States)

    Li, Xin; Ben-Dov, Iddo Z; Mauro, Maurizio; Williams, Zev

    2015-05-06

    RNA quantification is often a prerequisite for most RNA analyses such as RNA sequencing. However, the relatively low sensitivity and large sample consumption of traditional RNA quantification methods such as UV spectrophotometry and even the much more sensitive fluorescence-based RNA quantification assays, such as the Qubit™ RNA HS Assay, are often inadequate for measuring minute levels of RNA isolated from limited cell and tissue samples and biofluids. Thus, there is a pressing need for a more sensitive method to reliably and robustly detect trace levels of RNA without interference from DNA. To improve the quantification limit of the Qubit™ RNA HS Assay, we spiked-in a known quantity of RNA to achieve the minimum reading required by the assay. Samples containing trace amounts of RNA were then added to the spike-in and measured as a reading increase over RNA spike-in baseline. We determined the accuracy and precision of reading increases between 1 and 20 pg/μL as well as RNA-specificity in this range, and compared to those of RiboGreen(®), another sensitive fluorescence-based RNA quantification assay. We then applied Qubit™ Assay with RNA spike-in to quantify plasma RNA samples. RNA spike-in improved the quantification limit of the Qubit™ RNA HS Assay 5-fold, from 25 pg/μL down to 5 pg/μL while maintaining high specificity to RNA. This enabled quantification of RNA with original concentration as low as 55.6 pg/μL compared to 250 pg/μL for the standard assay and decreased sample consumption from 5 to 1 ng. Plasma RNA samples that were not measurable by the Qubit™ RNA HS Assay were measurable by our modified method. The Qubit™ RNA HS Assay with RNA spike-in is able to quantify RNA with high specificity at 5-fold lower concentration and uses 5-fold less sample quantity than the standard Qubit™ Assay.

  12. siRNA as an alternative therapy against viral infections

    Directory of Open Access Journals (Sweden)

    Hana A. Pawestri

    2012-07-01

    Full Text Available siRNA (small interfering ribonucleic acid adalah sebuah metode yang dapat digunakan untuk mengatasi infeksi virus yang prinsip kerjanya berdasarkan metode komplementer dsRNA (double stranded RNA pada RNA virus sehingga menyebabkan kegagalan proses transkripsi (silencing.  Untuk lebih memahami bagaimana proses kerja dan ulasan penelitian siRNA yang terkini, di dalam tulisan ini ditinjau siRNA sebagai metoda yang dikembangkan untuk mengatasi infeksi dan meneliti efeknya pada replikasi beberapa virus seperti Hepatitis C, Influenza, Polio, dan HIV. Kami menemukan bahwa urutan basa nukleotida dari target siRNA sangat penting. Hal tersebut harus homolog dengan target RNA virus dan tidak menganggu RNA sel inang. Untuk mengurangi kegagalan terapi siRNA oleh adanya mutasi, digunakan beberapa siRNA yang sekaligus menjadi target RNA virus yang berbeda. Namun demikian, terapi siRNA masih menghadapi beberapa kesulitan seperti pengiriman (transfer khusus ke jaringan yang terinfeksi dan perlindungan siRNA dari perusakan oleh nuklease. Berdasarkan beberapa penelitian yang telah dilakukan, siRNA dapat digunakan sebagai alternatif untuk mengobati infeksi yang disebabkan oleh virus. Terapi tersebut direkomendasikan untuk dilakukan uji klinis dengan memperhatikan beberapa aspek seperti desain siRNA dan mekanisme transfer. (Health Science Indones 2010; 1: 58 - 65 Kata kunci: siRNA, infeksi virus, target virus, alternatif terapi Abstract SiRNA is a promising method to deal with viral infections. The principle of siRNA is based on the complementarily of (synthetic dsRNA to an RNA virus which, in consequence, will be silenced. Many studies are currently examining the effects of siRNA on replication of diverse virus types like Hepatitis C, polio and HIV. The choice of the siRNA target sequence is crucial. It has to be very homologous to the target RNA, but it cannot target RNA of the host cell. To reduce the possibility for the virus to escape from the siRNA therapy by

  13. Mapping RNA-seq Reads with STAR.

    Science.gov (United States)

    Dobin, Alexander; Gingeras, Thomas R

    2015-09-03

    Mapping of large sets of high-throughput sequencing reads to a reference genome is one of the foundational steps in RNA-seq data analysis. The STAR software package performs this task with high levels of accuracy and speed. In addition to detecting annotated and novel splice junctions, STAR is capable of discovering more complex RNA sequence arrangements, such as chimeric and circular RNA. STAR can align spliced sequences of any length with moderate error rates, providing scalability for emerging sequencing technologies. STAR generates output files that can be used for many downstream analyses such as transcript/gene expression quantification, differential gene expression, novel isoform reconstruction, and signal visualization. In this unit, we describe computational protocols that produce various output files, use different RNA-seq datatypes, and utilize different mapping strategies. STAR is open source software that can be run on Unix, Linux, or Mac OS X systems. Copyright © 2015 John Wiley & Sons, Inc.

  14. Facilitating RNA structure prediction with microarrays.

    Science.gov (United States)

    Kierzek, Elzbieta; Kierzek, Ryszard; Turner, Douglas H; Catrina, Irina E

    2006-01-17

    Determining RNA secondary structure is important for understanding structure-function relationships and identifying potential drug targets. This paper reports the use of microarrays with heptamer 2'-O-methyl oligoribonucleotides to probe the secondary structure of an RNA and thereby improve the prediction of that secondary structure. When experimental constraints from hybridization results are added to a free-energy minimization algorithm, the prediction of the secondary structure of Escherichia coli 5S rRNA improves from 27 to 92% of the known canonical base pairs. Optimization of buffer conditions for hybridization and application of 2'-O-methyl-2-thiouridine to enhance binding and improve discrimination between AU and GU pairs are also described. The results suggest that probing RNA with oligonucleotide microarrays can facilitate determination of secondary structure.

  15. MicroRNA involvement in glioblastoma pathogenesis

    International Nuclear Information System (INIS)

    Novakova, Jana; Slaby, Ondrej; Vyzula, Rostislav; Michalek, Jaroslav

    2009-01-01

    MicroRNAs are endogenously expressed regulatory noncoding RNAs. Altered expression levels of several microRNAs have been observed in glioblastomas. Functions and direct mRNA targets for these microRNAs have been relatively well studied over the last years. According to these data, it is now evident, that impairment of microRNA regulatory network is one of the key mechanisms in glioblastoma pathogenesis. MicroRNA deregulation is involved in processes such as cell proliferation, apoptosis, cell cycle regulation, invasion, glioma stem cell behavior, and angiogenesis. In this review, we summarize the current knowledge of miRNA functions in glioblastoma with an emphasis on its significance in glioblastoma oncogenic signaling and its potential to serve as a disease biomarker and a novel therapeutic target in oncology.

  16. Nucleolin Mediates MicroRNA-directed CSF-1 mRNA Deadenylation but Increases Translation of CSF-1 mRNA*

    Science.gov (United States)

    Woo, Ho-Hyung; Baker, Terri; Laszlo, Csaba; Chambers, Setsuko K.

    2013-01-01

    CSF-1 mRNA 3′UTR contains multiple unique motifs, including a common microRNA (miRNA) target in close proximity to a noncanonical G-quadruplex and AU-rich elements (AREs). Using a luciferase reporter system fused to CSF-1 mRNA 3′UTR, disruption of the miRNA target region, G-quadruplex, and AREs together dramatically increased reporter RNA levels, suggesting important roles for these cis-acting regulatory elements in the down-regulation of CSF-1 mRNA. We find that nucleolin, which binds both G-quadruplex and AREs, enhances deadenylation of CSF-1 mRNA, promoting CSF-1 mRNA decay, while having the capacity to increase translation of CSF-1 mRNA. Through interaction with the CSF-1 3′UTR miRNA common target, we find that miR-130a and miR-301a inhibit CSF-1 expression by enhancing mRNA decay. Silencing of nucleolin prevents the miRNA-directed mRNA decay, indicating a requirement for nucleolin in miRNA activity on CSF-1 mRNA. Downstream effects followed by miR-130a and miR-301a inhibition of directed cellular motility of ovarian cancer cells were found to be dependent on nucleolin. The paradoxical effects of nucleolin on miRNA-directed CSF-1 mRNA deadenylation and on translational activation were explored further. The nucleolin protein contains four acidic stretches, four RNA recognition motifs (RRMs), and nine RGG repeats. All three domains in nucleolin regulate CSF-1 mRNA and protein levels. RRMs increase CSF-1 mRNA, whereas the acidic and RGG domains decrease CSF-1 protein levels. This suggests that nucleolin has the capacity to differentially regulate both CSF-1 RNA and protein levels. Our finding that nucleolin interacts with Ago2 indirectly via RNA and with poly(A)-binding protein C (PABPC) directly suggests a nucleolin-Ago2-PABPC complex formation on mRNA. This complex is in keeping with our suggestion that nucleolin may work with PABPC as a double-edged sword on both mRNA deadenylation and translational activation. Our findings underscore the complexity of

  17. Reconstruction and analysis of the lncRNA-miRNA-mRNA network based on competitive endogenous RNA reveal functional lncRNAs in rheumatoid arthritis.

    Science.gov (United States)

    Jiang, Hui; Ma, Rong; Zou, Shubiao; Wang, Yongzhong; Li, Zhuqing; Li, Weiping

    2017-06-01

    Rheumatoid arthritis (RA) is an autoimmune disease with an unknown etiology, occurring in approximately 1.0% of general population. More and more studies have suggested that long non-coding RNAs (lncRNAs) could play important roles in various biological processes and be associated with the pathogenesis of different kinds of diseases including RA. Although a large number of lncRNAs have been found, our knowledge of their function and physiological/pathological significance is still in its infancy. In order to reveal functional lncRNAs and identify the key lncRNAs in RA, we reconstructed a global triple network based on the competitive endogenous RNA (ceRNA) theory using the data from National Center for Biotechnology Information Gene Expression Omnibus and our previous paper. Meanwhile, Gene Ontology (GO) and pathway analysis were performed using Cytoscape plug-in BinGO and Database for Annotation, Visualization, and Integration Discovery (DAVID), respectively. We found that the lncRNA-miRNA-mRNA network was composed of 7 lncRNA nodes, 90 mRNA nodes, 24 miRNA nodes, and 301 edges. The functional assay showed that 147 GO terms and 23 pathways were enriched. In addition, three lncRNAs (S5645.1, XR_006437.1, J01878) were highly related to RA, and therefore, were selected as key lncRNAs. This study suggests that specific lncRNAs are associated with the development of RA, and three lncRNAs (S5645.1, XR_006437.1, J01878) could be used as potential diagnostic biomarkers and therapeutic targets.

  18. Self-amplifying mRNA vaccines.

    Science.gov (United States)

    Brito, Luis A; Kommareddy, Sushma; Maione, Domenico; Uematsu, Yasushi; Giovani, Cinzia; Berlanda Scorza, Francesco; Otten, Gillis R; Yu, Dong; Mandl, Christian W; Mason, Peter W; Dormitzer, Philip R; Ulmer, Jeffrey B; Geall, Andrew J

    2015-01-01

    This chapter provides a brief introduction to nucleic acid-based vaccines and recent research in developing self-amplifying mRNA vaccines. These vaccines promise the flexibility of plasmid DNA vaccines with enhanced immunogenicity and safety. The key to realizing the full potential of these vaccines is efficient delivery of nucleic acid to the cytoplasm of a cell, where it can amplify and express the encoded antigenic protein. The hydrophilicity and strong net negative charge of RNA impedes cellular uptake. To overcome this limitation, electrostatic complexation with cationic lipids or polymers and physical delivery using electroporation or ballistic particles to improve cellular uptake has been evaluated. This chapter highlights the rapid progress made in using nonviral delivery systems for RNA-based vaccines. Initial preclinical testing of self-amplifying mRNA vaccines has shown nonviral delivery to be capable of producing potent and robust innate and adaptive immune responses in small animals and nonhuman primates. Historically, the prospect of developing mRNA vaccines was uncertain due to concerns of mRNA instability and the feasibility of large-scale manufacturing. Today, these issues are no longer perceived as barriers in the widespread implementation of the technology. Currently, nonamplifying mRNA vaccines are under investigation in human clinical trials and can be produced at a sufficient quantity and quality to meet regulatory requirements. If the encouraging preclinical data with self-amplifying mRNA vaccines are matched by equivalently positive immunogenicity, potency, and tolerability in human trials, this platform could establish nucleic acid vaccines as a versatile new tool for human immunization. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Modelling Toehold-Mediated RNA Strand Displacement

    OpenAIRE

    Šulc, Petr; Ouldridge, Thomas E.; Romano, Flavio; Doye, Jonathan P.K.; Louis, Ard A.

    2015-01-01

    We study the thermodynamics and kinetics of an RNA toehold-mediated strand displacement reaction with a recently developed coarse-grained model of RNA. Strand displacement, during which a single strand displaces a different strand previously bound to a complementary substrate strand, is an essential mechanism in active nucleic acid nanotechnology and has also been hypothesized to occur in vivo. We study the rate of displacement reactions as a function of the length of the toehold and temperat...

  20. Rfam: updates to the RNA families database

    DEFF Research Database (Denmark)

    Gardner, Paul P; Daub, Jennifer; Tate, John G

    2008-01-01

    Rfam is a collection of RNA sequence families, represented by multiple sequence alignments and covariance models (CMs). The primary aim of Rfam is to annotate new members of known RNA families on nucleotide sequences, particularly complete genomes, using sensitive BLAST filters in combination...... to the website, methodologies and data used by Rfam are discussed. Rfam is freely available on the Web at http://rfam.sanger.ac.uk/and http://rfam.janelia.org/....

  1. RNA search engines empower the bacterial intranet

    OpenAIRE

    Dendooven, T; Luisi, Bonaventura Francesco

    2017-01-01

    RNA acts not only as an information bearer in the biogenesis of proteins from genes, but also as a regulator that participates in the control of gene expression. In bacteria, small RNA molecules (sRNAs) play controlling roles in numerous processes and help to orchestrate complex regulatory networks. Such processes include cell growth and development, response to stress and metabolic change, transcription termination, cell-to-cell communication, and the launching of programmes for host invasio...

  2. Prebiotic RNA Synthesis by Montmorillonite Catalysis

    Directory of Open Access Journals (Sweden)

    Sohan Jheeta

    2014-08-01

    Full Text Available This review summarizes our recent findings on the role of mineral salts in prebiotic RNA synthesis, which is catalyzed by montmorillonite clay minerals. The clay minerals not only catalyze the synthesis of RNA but also facilitate homochiral selection. Preliminary data of these findings have been presented at the “Horizontal Gene Transfer and the Last Universal Common Ancestor (LUCA” conference at the Open University, Milton Keynes, UK, 5–6 September 2013. The objective of this meeting was to recognize the significance of RNA in LUCA. We believe that the prebiotic RNA synthesis from its monomers must have been a simple process. As a first step, it may have required activation of the 5'-end of the mononucleotide with a leaving group, e.g., imidazole in our model reaction (Figure 1. Wide ranges of activating groups are produced from HCN under plausible prebiotic Earth conditions. The final step is clay mineral catalysis in the presence of mineral salts to facilitate selective production of functional RNA. Both the clay minerals and mineral salts would have been abundant on early Earth. We have demonstrated that while montmorillonite (pH 7 produced only dimers from its monomers in water, addition of sodium chloride (1 M enhanced the chain length multifold, as detected by HPLC. The effect of monovalent cations on RNA synthesis was of the following order: Li+ > Na+ > K+. A similar effect was observed with the anions, enhancing catalysis in the following order: Cl− > Br− > I−. The montmorillonite-catalyzed RNA synthesis was not affected by hydrophobic or hydrophilic interactions. We thus show that prebiotic synthesis of RNA from its monomers was a simple process requiring only clay minerals and a small amount of salt.

  3. The Spot 42 RNA: A regulatory small RNA with roles in the central metabolism

    Science.gov (United States)

    Bækkedal, Cecilie; Haugen, Peik

    2015-01-01

    The Spot 42 RNA is a 109 nucleotide long (in Escherichia coli) noncoding small regulatory RNA (sRNA) encoded by the spf (spot fourty-two) gene. spf is found in gamma-proteobacteria and the majority of experimental work on Spot 42 RNA has been performed using E. coli, and recently Aliivibrio salmonicida. In the cell Spot 42 RNA plays essential roles as a regulator in carbohydrate metabolism and uptake, and its expression is activated by glucose, and inhibited by the cAMP-CRP complex. Here we summarize the current knowledge on Spot 42, and present the natural distribution of spf, show family-specific secondary structural features of Spot 42, and link highly conserved structural regions to mRNA target binding. PMID:26327359

  4. The replisome uses mRNA as a primer after colliding with RNA polymerase.

    Science.gov (United States)

    Pomerantz, Richard T; O'Donnell, Mike

    2008-12-11

    Replication forks are impeded by DNA damage and protein-nucleic acid complexes such as transcribing RNA polymerase. For example, head-on collision of the replisome with RNA polymerase results in replication fork arrest. However, co-directional collision of the replisome with RNA polymerase has little or no effect on fork progression. Here we examine co-directional collisions between a replisome and RNA polymerase in vitro. We show that the Escherichia coli replisome uses the RNA transcript as a primer to continue leading-strand synthesis after the collision with RNA polymerase that is displaced from the DNA. This action results in a discontinuity in the leading strand, yet the replisome remains intact and bound to DNA during the entire process. These findings underscore the notable plasticity by which the replisome operates to circumvent obstacles in its path and may explain why the leading strand is synthesized discontinuously in vivo.

  5. Comprehensive analysis of RNA-Seq data reveals extensive RNA editing in a human transcriptome

    DEFF Research Database (Denmark)

    Peng, Zhiyu; Cheng, Yanbing; Tan, Bertrand Chin-Ming

    2012-01-01

    a computational pipeline that carefully controls for false positives while calling RNA editing events from genome and whole-transcriptome data of the same individual. We identified 22,688 RNA editing events in noncoding genes and introns, untranslated regions and coding sequences of protein-coding genes. Most......RNA editing is a post-transcriptional event that recodes hereditary information. Here we describe a comprehensive profile of the RNA editome of a male Han Chinese individual based on analysis of ∼767 million sequencing reads from poly(A)(+), poly(A)(-) and small RNA samples. We developed...... changes (∼93%) converted A to I(G), consistent with known editing mechanisms based on adenosine deaminase acting on RNA (ADAR). We also found evidence of other types of nucleotide changes; however, these were validated at lower rates. We found 44 editing sites in microRNAs (miRNAs), suggesting a potential...

  6. The Spot 42 RNA: A regulatory small RNA with roles in the central metabolism.

    Science.gov (United States)

    Bækkedal, Cecilie; Haugen, Peik

    2015-01-01

    The Spot 42 RNA is a 109 nucleotide long (in Escherichia coli) noncoding small regulatory RNA (sRNA) encoded by the spf (spot fourty-two) gene. spf is found in gamma-proteobacteria and the majority of experimental work on Spot 42 RNA has been performed using E. coli, and recently Aliivibrio salmonicida. In the cell Spot 42 RNA plays essential roles as a regulator in carbohydrate metabolism and uptake, and its expression is activated by glucose, and inhibited by the cAMP-CRP complex. Here we summarize the current knowledge on Spot 42, and present the natural distribution of spf, show family-specific secondary structural features of Spot 42, and link highly conserved structural regions to mRNA target binding.

  7. A Two-Way Street: Regulatory Interplay between RNA Polymerase and Nascent RNA Structure.

    Science.gov (United States)

    Zhang, Jinwei; Landick, Robert

    2016-04-01

    The vectorial (5'-to-3' at varying velocity) synthesis of RNA by cellular RNA polymerases (RNAPs) creates a rugged kinetic landscape, demarcated by frequent, sometimes long-lived, pauses. In addition to myriad gene-regulatory roles, these pauses temporally and spatially program the co-transcriptional, hierarchical folding of biologically active RNAs. Conversely, these RNA structures, which form inside or near the RNA exit channel, interact with the polymerase and adjacent protein factors to influence RNA synthesis by modulating pausing, termination, antitermination, and slippage. Here, we review the evolutionary origin, mechanistic underpinnings, and regulatory consequences of this interplay between RNAP and nascent RNA structure. We categorize and rationalize the extensive linkage between the transcriptional machinery and its product, and provide a framework for future studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. New windows into retroviral RNA structures.

    Science.gov (United States)

    Jayaraman, Dhivya; Kenyon, Julia Claire

    2018-01-25

    The multiple roles of both viral and cellular RNAs have become increasingly apparent in recent years, and techniques to model them have become significantly more powerful, enabling faster and more accurate visualization of RNA structures. Techniques such as SHAPE (selective 2'OH acylation analysed by primer extension) have revolutionized the field, and have been used to examine RNAs belonging to many and diverse retroviruses. Secondary structure probing reagents such as these have been aided by the development of faster methods of analysis either via capillary or next-generation sequencing, allowing the analysis of entire genomes, and of retroviral RNA structures within virions. Techniques to model the three-dimensional structures of these large RNAs have also recently developed. The flexibility of retroviral RNAs, both structural and functional, is clear from the results of these new experimental techniques. Retroviral RNA structures and structural changes control many stages of the lifecycle, and both the RNA structures themselves and their interactions with ligands are potential new drug targets. In addition, our growing understanding of retroviral RNA structures is aiding our knowledge of cellular RNA form and function.

  9. RNA secondary structure prediction using soft computing.

    Science.gov (United States)

    Ray, Shubhra Sankar; Pal, Sankar K

    2013-01-01

    Prediction of RNA structure is invaluable in creating new drugs and understanding genetic diseases. Several deterministic algorithms and soft computing-based techniques have been developed for more than a decade to determine the structure from a known RNA sequence. Soft computing gained importance with the need to get approximate solutions for RNA sequences by considering the issues related with kinetic effects, cotranscriptional folding, and estimation of certain energy parameters. A brief description of some of the soft computing-based techniques, developed for RNA secondary structure prediction, is presented along with their relevance. The basic concepts of RNA and its different structural elements like helix, bulge, hairpin loop, internal loop, and multiloop are described. These are followed by different methodologies, employing genetic algorithms, artificial neural networks, and fuzzy logic. The role of various metaheuristics, like simulated annealing, particle swarm optimization, ant colony optimization, and tabu search is also discussed. A relative comparison among different techniques, in predicting 12 known RNA secondary structures, is presented, as an example. Future challenging issues are then mentioned.

  10. Bleomycin Can Cleave an Oncogenic Noncoding RNA.

    Science.gov (United States)

    Angelbello, Alicia J; Disney, Matthew D

    2018-01-04

    Noncoding RNAs are pervasive in cells and contribute to diseases such as cancer. A question in biomedical research is whether noncoding RNAs are targets of medicines. Bleomycin is a natural product that cleaves DNA; however, it is known to cleave RNA in vitro. Herein, an in-depth analysis of the RNA cleavage preferences of bleomycin A5 is presented. Bleomycin A5 prefers to cleave RNAs with stretches of AU base pairs. Based on these preferences and bioinformatic analysis, the microRNA-10b hairpin precursor was identified as a potential substrate for bleomycin A5. Both in vitro and cellular experiments demonstrated cleavage. Importantly, chemical cleavage by bleomycin A5 in the microRNA-10b hairpin precursors occurred near the Drosha and Dicer enzymatic processing sites and led to destruction of the microRNA. Evidently, oncogenic noncoding RNAs can be considered targets of cancer medicines and might elicit their pharmacological effects by targeting noncoding RNA. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. RNA Relics and Origin of Life

    Directory of Open Access Journals (Sweden)

    Laurent Vial

    2009-07-01

    Full Text Available A number of small RNA sequences, located in different non-coding sequences and highly preserved across the tree of life, have been suggested to be molecular fossils, of ancient (and possibly primordial origin. On the other hand, recent years have revealed the existence of ubiquitous roles for small RNA sequences in modern organisms, in functions ranging from cell regulation to antiviral activity. We propose that a single thread can be followed from the beginning of life in RNA structures selected only for stability reasons through the RNA relics and up to the current coevolution of RNA sequences; such an understanding would shed light both on the history and on the present development of the RNA machinery and interactions. After presenting the evidence (by comparing their sequences that points toward a common thread, we discuss a scenario of genome coevolution (with emphasis on viral infectious processes and finally propose a plan for the reevaluation of the stereochemical theory of the genetic code; we claim that it may still be relevant, and not only for understanding the origin of life, but also for a comprehensive picture of regulation in present-day cells.

  12. RNA Relics and Origin of Life

    Science.gov (United States)

    Demongeot, Jacques; Glade, Nicolas; Moreira, Andrés; Vial, Laurent

    2009-01-01

    A number of small RNA sequences, located in different non-coding sequences and highly preserved across the tree of life, have been suggested to be molecular fossils, of ancient (and possibly primordial) origin. On the other hand, recent years have revealed the existence of ubiquitous roles for small RNA sequences in modern organisms, in functions ranging from cell regulation to antiviral activity. We propose that a single thread can be followed from the beginning of life in RNA structures selected only for stability reasons through the RNA relics and up to the current coevolution of RNA sequences; such an understanding would shed light both on the history and on the present development of the RNA machinery and interactions. After presenting the evidence (by comparing their sequences) that points toward a common thread, we discuss a scenario of genome coevolution (with emphasis on viral infectious processes) and finally propose a plan for the reevaluation of the stereochemical theory of the genetic code; we claim that it may still be relevant, and not only for understanding the origin of life, but also for a comprehensive picture of regulation in present-day cells. PMID:20111682

  13. RNA Export through the NPC in Eukaryotes.

    Science.gov (United States)

    Okamura, Masumi; Inose, Haruko; Masuda, Seiji

    2015-03-20

    In eukaryotic cells, RNAs are transcribed in the nucleus and exported to the cytoplasm through the nuclear pore complex. The RNA molecules that are exported from the nucleus into the cytoplasm include messenger RNAs (mRNAs), ribosomal RNAs (rRNAs), transfer RNAs (tRNAs), small nuclear RNAs (snRNAs), micro RNAs (miRNAs), and viral mRNAs. Each RNA is transported by a specific nuclear export receptor. It is believed that most of the mRNAs are exported by Nxf1 (Mex67 in yeast), whereas rRNAs, snRNAs, and a certain subset of mRNAs are exported in a Crm1/Xpo1-dependent manner. tRNAs and miRNAs are exported by Xpot and Xpo5. However, multiple export receptors are involved in the export of some RNAs, such as 60S ribosomal subunit. In addition to these export receptors, some adapter proteins are required to export RNAs. The RNA export system of eukaryotic cells is also used by several types of RNA virus that depend on the machineries of the host cell in the nucleus for replication of their genome, therefore this review describes the RNA export system of two representative viruses. We also discuss the NPC anchoring-dependent mRNA export factors that directly recruit specific genes to the NPC.

  14. Small Molecule Modifiers of the microRNA and RNA Interference Pathway

    OpenAIRE

    Deiters, Alexander

    2009-01-01

    Recently, the RNA interference (RNAi) pathway has become the target of small molecule inhibitors and activators. RNAi has been well established as a research tool in the sequence-specific silencing of genes in eukaryotic cells and organisms by using exogenous, small, double-stranded RNA molecules of approximately 20 nucleotides. Moreover, a recently discovered post-transcriptional gene regulatory mechanism employs microRNAs (miRNAs), a class of endogenously expressed small RNA molecules, whic...

  15. Steric restrictions of RISC in RNA interference identified with size-expanded RNA nucleobases.

    Science.gov (United States)

    Hernández, Armando R; Peterson, Larryn W; Kool, Eric T

    2012-08-17

    Understanding the interactions between small interfering RNAs (siRNAs) and the RNA-induced silencing complex (RISC), the key protein complex of RNA interference (RNAi), is of great importance to the development of siRNAs with improved biological and potentially therapeutic function. Although various chemically modified siRNAs have been reported, relatively few studies with modified nucleobases exist. Here we describe the synthesis and hybridization properties of siRNAs bearing size-expanded RNA (xRNA) nucleobases and their use as a novel and systematic set of steric probes in RNAi. xRNA nucleobases are expanded by 2.4 Å using benzo-homologation and retain canonical Watson-Crick base-pairing groups. Our data show that the modified siRNA duplexes display small changes in melting temperature (+1.4 to -5.0 °C); substitutions near the center are somewhat destabilizing to the RNA duplex, while substitutions near the ends are stabilizing. RNAi studies in a dual-reporter luciferase assay in HeLa cells revealed that xRNA nucleobases in the antisense strand reduce activity at some central positions near the seed region but are generally well tolerated near the ends. Most importantly, we observed that xRNA substitutions near the 3'-end increased activity over that of wild-type siRNAs. The data are analyzed in terms of site-dependent steric effects in RISC. Circular dichroism experiments show that single xRNA substitutions do not significantly distort the native A-form helical structure of the siRNA duplex, and serum stability studies demonstrated that xRNA substitutions protect siRNAs against nuclease degradation.

  16. Characterizing the transcriptome upon depletion of RNA processing factors

    DEFF Research Database (Denmark)

    Herudek, Jan

    , it is not clear how they target and discriminate their RNA substrates. Moreover, many novel RNA species are poorly characterized and their function is not understood. Over the last decade, protein function has been studied using RNA interference. However, this approach does not allow investigation of instant......The human genome is pervasively transcribed and produces an enormous amount of non-coding RNA (ncRNA). Compared to protein-coding transcripts, many classes of ncRNAs are very unstable and rapidly degraded by the RNA decay machinery. The RNA exosome complex is a main RNA ‘degrader’ in the human...... nucleus and is responsible for the proper processing and decay of a wide range of RNA molecules. Notably, the RNA exosome complex associates with a plethora of co-factors and activators that assist in the recognition of specific RNA substrates. Although many exosome partners have been characterized...

  17. RNA-SeQC: RNA-seq metrics for quality control and process optimization.

    Science.gov (United States)

    DeLuca, David S; Levin, Joshua Z; Sivachenko, Andrey; Fennell, Timothy; Nazaire, Marc-Danie; Williams, Chris; Reich, Michael; Winckler, Wendy; Getz, Gad

    2012-06-01

    RNA-seq, the application of next-generation sequencing to RNA, provides transcriptome-wide characterization of cellular activity. Assessment of sequencing performance and library quality is critical to the interpretation of RNA-seq data, yet few tools exist to address this issue. We introduce RNA-SeQC, a program which provides key measures of data quality. These metrics include yield, alignment and duplication rates; GC bias, rRNA content, regions of alignment (exon, intron and intragenic), continuity of coverage, 3'/5' bias and count of detectable transcripts, among others. The software provides multi-sample evaluation of library construction protocols, input materials and other experimental parameters. The modularity of the software enables pipeline integration and the routine monitoring of key measures of data quality such as the number of alignable reads, duplication rates and rRNA contamination. RNA-SeQC allows investigators to make informed decisions about sample inclusion in downstream analysis. In summary, RNA-SeQC provides quality control measures critical to experiment design, process optimization and downstream computational analysis. See www.genepattern.org to run online, or www.broadinstitute.org/rna-seqc/ for a command line tool.

  18. Site-Specific Covalent Conjugation of Modified mRNA by tRNA Guanine Transglycosylase.

    Science.gov (United States)

    Ehret, Fabian; Zhou, Cun Yu; Alexander, Seth C; Zhang, Dongyang; Devaraj, Neal K

    2018-03-05

    Modified mRNA (mod-mRNA) has recently been widely studied as the form of RNA useful for therapeutic applications due to its high stability and lowered immune response. Herein, we extend the scope of the recently established RNA-TAG (transglycosylation at guanosine) methodology, a novel approach for genetically encoded site-specific labeling of large mRNA transcripts, by employing mod-mRNA as substrate. As a proof of concept, we covalently attached a fluorescent probe to mCherry encoding mod-mRNA transcripts bearing 5-methylcytidine and/or pseudouridine substitutions with high labeling efficiencies. To provide a versatile labeling methodology with a wide range of possible applications, we employed a two-step strategy for functionalization of the mod-mRNA to highlight the therapeutic potential of this new methodology. We envision that this novel and facile labeling methodology of mod-RNA will have great potential in decorating both coding and noncoding therapeutic RNAs with a variety of diagnostic and functional moieties.

  19. A Broad RNA Virus Survey Reveals Both miRNA Dependence and Functional Sequestration

    DEFF Research Database (Denmark)

    Scheel, Troels K H; Luna, Joseph M; Liniger, Matthias

    2016-01-01

    , critically depended on the interaction of cellular miR-17 and let-7 with the viral 3' UTR. Unlike canonical miRNA interactions, miR-17 and let-7 binding enhanced pestivirus translation and RNA stability. miR-17 sequestration by pestiviruses conferred reduced AGO binding and functional de...... immunoprecipitation (CLIP) of the Argonaute (AGO) proteins to characterize strengths and specificities of miRNA interactions in the context of 15 different RNA virus infections, including several clinically relevant pathogens. Notably, replication of pestiviruses, a major threat to milk and meat industries...

  20. RNA Interference and its therapeutic applications

    Directory of Open Access Journals (Sweden)

    Srinivasa Rao T

    2011-10-01

    Full Text Available RNAi is a potent method, requiring only a few molecules of dsRNA per cell to silence the expression. Long molecules of double stranded RNA (dsRNA trigger the process. The dsRNA comes from virus and transposon activity in natural RNAi process, while it can be injected in the cells in experimental processes. The strand of the dsRNA that is identical in sequence to a region in target mRNA molecule is called the sense strand, and the other strand which is complimentary is termed the antisense strand. An enzyme complex called DICER thought to be similar to RNAase III then recognizes dsRNA, and cuts it into roughly 22- nucleotide long fragments. These fragments termed siRNAs for “small interfering RNAs” remain in double stranded duplexes with very short 3' overhangs. However, only one of the two strands, known as the guide strand or antisense strand binds the argonaute protein of RNA-induced silencing complex (RISC and target the complementary mRNA resulting gene silencing. The other anti-guide strand or passenger strand is degraded as a RISC substrate during the process of RISC activation. This form of RNAi is termed as post transcriptional gene silencing (PTGS; other forms are also thought to operate at the genomic or transcriptional level in some organisms. In mammals dsRNA longer than 30 base pairs induces a nonspecific antiviral response. This so-called interferon response results in a nonspecific arrest in translation and induction of apoptosis. This cascade induces a global non-specific suppression of translation, which in turn triggers apoptosis. Interestingly, dsRNAs less than 30 nt in length do not activate the antiviral response and specifically switched off genes in human cells without initiating the acute phase response. Thus these siRNAs are suitable for gene target validation and therapeutic applications in many species, including humans. [Vet. World 2011; 4(5.000: 225-229

  1. Species-independent MicroRNA Gene Discovery

    KAUST Repository

    Kamanu, Timothy K.

    2012-12-01

    MicroRNA (miRNA) are a class of small endogenous non-coding RNA that are mainly negative transcriptional and post-transcriptional regulators in both plants and animals. Recent studies have shown that miRNA are involved in different types of cancer and other incurable diseases such as autism and Alzheimer’s. Functional miRNAs are excised from hairpin-like sequences that are known as miRNA genes. There are about 21,000 known miRNA genes, most of which have been determined using experimental methods. miRNA genes are classified into different groups (miRNA families). This study reports about 19,000 unknown miRNA genes in nine species whereby approximately 15,300 predictions were computationally validated to contain at least one experimentally verified functional miRNA product. The predictions are based on a novel computational strategy which relies on miRNA family groupings and exploits the physics and geometry of miRNA genes to unveil the hidden palindromic signals and symmetries in miRNA gene sequences. Unlike conventional computational miRNA gene discovery methods, the algorithm developed here is species-independent: it allows prediction at higher accuracy and resolution from arbitrary RNA/DNA sequences in any species and thus enables examination of repeat-prone genomic regions which are thought to be non-informative or ’junk’ sequences. The information non-redundancy of uni-directional RNA sequences compared to information redundancy of bi-directional DNA is demonstrated, a fact that is overlooked by most pattern discovery algorithms. A novel method for computing upstream and downstream miRNA gene boundaries based on mathematical/statistical functions is suggested, as well as cutoffs for annotation of miRNA genes in different miRNA families. Another tool is proposed to allow hypotheses generation and visualization of data matrices, intra- and inter-species chromosomal distribution of miRNA genes or miRNA families. Our results indicate that: miRNA and miRNA

  2. ncRNA-class Web Tool: Non-coding RNA feature extraction and pre-miRNA classification web tool

    KAUST Repository

    Kleftogiannis, Dimitrios A.; Theofilatos, Konstantinos A.; Papadimitriou, Stergios; Tsakalidis, Athanasios K.; Likothanassis, Spiridon D.; Mavroudi, Seferina P.

    2012-01-01

    Until recently, it was commonly accepted that most genetic information is transacted by proteins. Recent evidence suggests that the majority of the genomes of mammals and other complex organisms are in fact transcribed into non-coding RNAs (ncRNAs), many of which are alternatively spliced and/or processed into smaller products. Non coding RNA genes analysis requires the calculation of several sequential, thermodynamical and structural features. Many independent tools have already been developed for the efficient calculation of such features but to the best of our knowledge there does not exist any integrative approach for this task. The most significant amount of existing work is related to the miRNA class of non-coding RNAs. MicroRNAs (miRNAs) are small non-coding RNAs that play a significant role in gene regulation and their prediction is a challenging bioinformatics problem. Non-coding RNA feature extraction and pre-miRNA classification Web Tool (ncRNA-class Web Tool) is a publicly available web tool ( http://150.140.142.24:82/Default.aspx ) which provides a user friendly and efficient environment for the effective calculation of a set of 58 sequential, thermodynamical and structural features of non-coding RNAs, plus a tool for the accurate prediction of miRNAs. © 2012 IFIP International Federation for Information Processing.

  3. Identification of RNA species in the RNA-toxin complex and structure of the complex in Clostridium botulinum type E.

    Science.gov (United States)

    Kitamura, Masaru

    2002-02-15

    Clostridium botulinum type E toxin was isolated in the form of a complex with RNA(s) from bacterial cells. Characterization of the complexed RNA remains to be elucidated. The RNA is identified here as ribosomal RNA (rRNA) having 23S and 16S components. The RNA-toxin complexes were found to be made up of three types with different molecular sizes. The three types of RNA-toxin complex are toxin bound to both the 23S and 16S rRNA, toxin bound to the 16S rRNA and a small amount of 23S rRNA, and toxin bound only to the 16S rRNA. ©2002 Elsevier Science (USA).

  4. Vitamin D and alternative splicing of RNA.

    Science.gov (United States)

    Zhou, Rui; Chun, Rene F; Lisse, Thomas S; Garcia, Alejandro J; Xu, Jianzhong; Adams, John S; Hewison, Martin

    2015-04-01

    The active form of vitamin D (1α,25-dihydroxyvitamin D, 1,25(OH)2D) exerts its genomic effects via binding to a nuclear high-affinity vitamin D receptor (VDR). Recent deep sequencing analysis of VDR binding locations across the complete genome has significantly expanded our understanding of the actions of vitamin D and VDR on gene transcription. However, these studies have also promoted appreciation of the extra-transcriptional impact of vitamin D on gene expression. It is now clear that vitamin D interacts with the epigenome via effects on DNA methylation, histone acetylation, and microRNA generation to maintain normal biological functions. There is also increasing evidence that vitamin D can influence pre-mRNA constitutive splicing and alternative splicing, although the mechanism for this remains unclear. Pre-mRNA splicing has long been thought to be a post-transcription RNA processing event, but current data indicate that this occurs co-transcriptionally. Several steroid hormones have been recognized to coordinately control gene transcription and pre-mRNA splicing through the recruitment of nuclear receptor co-regulators that can both control gene transcription and splicing. The current review will discuss this concept with specific reference to vitamin D, and the potential role of heterogeneous nuclear ribonucleoprotein C (hnRNPC), a nuclear factor with an established function in RNA splicing. hnRNPC, has been shown to be involved in the VDR transcriptional complex as a vitamin D-response element-binding protein (VDRE-BP), and may act as a coupling factor linking VDR-directed gene transcription with RNA splicing. In this way hnRNPC may provide an additional mechanism for the fine-tuning of vitamin D-regulated target gene expression. This article is part of a Special Issue entitled '17th Vitamin D Workshop'. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. A novel TBP-TAF complex on RNA polymerase II-transcribed snRNA genes.

    Science.gov (United States)

    Zaborowska, Justyna; Taylor, Alice; Roeder, Robert G; Murphy, Shona

    2012-01-01

    Initiation of transcription of most human genes transcribed by RNA polymerase II (RNAP II) requires the formation of a preinitiation complex comprising TFIIA, B, D, E, F, H and RNAP II. The general transcription factor TFIID is composed of the TATA-binding protein and up to 13 TBP-associated factors. During transcription of snRNA genes, RNAP II does not appear to make the transition to long-range productive elongation, as happens during transcription of protein-coding genes. In addition, recognition of the snRNA gene-type specific 3' box RNA processing element requires initiation from an snRNA gene promoter. These characteristics may, at least in part, be driven by factors recruited to the promoter. For example, differences in the complement of TAFs might result in differential recruitment of elongation and RNA processing factors. As precedent, it already has been shown that the promoters of some protein-coding genes do not recruit all the TAFs found in TFIID. Although TAF5 has been shown to be associated with RNAP II-transcribed snRNA genes, the full complement of TAFs associated with these genes has remained unclear. Here we show, using a ChIP and siRNA-mediated approach, that the TBP/TAF complex on snRNA genes differs from that found on protein-coding genes. Interestingly, the largest TAF, TAF1, and the core TAFs, TAF10 and TAF4, are not detected on snRNA genes. We propose that this snRNA gene-specific TAF subset plays a key role in gene type-specific control of expression.

  6. RNA precursor pool metabolism and RNA synthesis in X-irradiated Tetrahymena

    International Nuclear Information System (INIS)

    Stephens, R.E.; Paul, I.J.; Zimmerman, A.M.

    1976-01-01

    The incorporation of a radioactive RNA precursor ( 3 H-uridine) has been used in many studies as an index for measuring the synthesis of RNA, yet there is a distinct possibility that the results so obtained were significantly influenced by radiation-induced effects on the metabolism of this precursor into UTP (the primary immediate precursor of RNA) before its incorporation into RNA. A direct examination was therefore undertaken of the effects of X-irradiation on the metabolism of 3 H-uridine and its relationship to RNA synthesis as determined by incorporation. X-irradiation of logarithmically growing Tetrahymena pyriformis caused a dose-dependent depression of total cellular RNA synthesis. Ribosomal RNA (which comprises about 80 per cent of total cellular RNA) synthesis was also depressed by X-irradiation in a dose-dependent manner. Measurements of the levels of radioactivity present in the UTP precursor pool of both irradiated and unirradiated cells were obtained by means of DEAE-cellulose column chromatography of the extracted free nucleotides. Metabolism of 3 H-uridine into UMP, UDP and UTP was depressed by 40%, 26% and 27% respectively, whereas incorporation of 3 H-uridine into RNA was depressed by 77%. The results show that about one-third of the observed (apparent) depression in RNA synthesis was due to radiation-induced effects on the precursor pool, and the remaining two-thirds due to some definite effect of radiation at the transcription level leading to depressed synthesis of RNA. (U.K.)

  7. Extraction of low molecular weight RNA from Citrus trifolita tissues ...

    African Journals Online (AJOL)

    Jane

    2010-12-20

    Dec 20, 2010 ... A critical prerequisite in miRNA studies is acquisition of high quality LMW RNA. LMW RNA is ..... air-dried for a few minutes and then exposed to BIOMAX X-ray film for 48 h using an .... Approaches to microRNA discovery. Nat.

  8. RAIN: RNA-protein Association and Interaction Networks

    DEFF Research Database (Denmark)

    Junge, Alexander; Refsgaard, Jan Christian; Garde, Christian

    2017-01-01

    is challenging due to data heterogeneity. Here, we present a database of ncRNA-RNA and ncRNA-protein interactions and its integration with the STRING database of protein-protein interactions. These ncRNA associations cover four organisms and have been established from curated examples, experimental data...

  9. Interaction of sulforaphane with DNA and RNA.

    Directory of Open Access Journals (Sweden)

    Farzaneh Abassi Joozdani

    Full Text Available Sulforaphane (SFN is an isothiocyanate found in cruciferous vegetables with anti-inflammatory, anti-oxidant and anti-cancer activities. However, the antioxidant and anticancer mechanism of sulforaphane is not well understood. In the present research, we reported binding modes, binding constants and stability of SFN-DNA and -RNA complexes by Fourier transform infrared (FTIR and UV-Visible spectroscopic methods. Spectroscopic evidence showed DNA intercalation with some degree of groove binding. SFN binds minor and major grooves of DNA and backbone phosphate (PO2, while RNA binding is through G, U, A bases with some degree of SFN-phosphate (PO2 interaction. Overall binding constants were estimated to be K(SFN-DNA=3.01 (± 0.035×10(4 M(-1 and K(SFN-RNA= 6.63 (±0.042×10(3 M(-1. At high SFN concentration (SFN/RNA = 1/1, DNA conformation changed from B to A occurred, while RNA remained in A-family structure.

  10. tmRDB (tmRNA database)

    DEFF Research Database (Denmark)

    Zwieb, Christian; Gorodkin, Jan; Knudsen, Bjarne

    2003-01-01

    Maintained at the University of Texas Health Science Center at Tyler, Texas, the tmRNA database (tmRDB) is accessible at the URL http://psyche.uthct.edu/dbs/tmRDB/tmRDB.html with mirror sites located at Auburn University, Auburn, Alabama (http://www.ag.auburn.edu/mirror/tmRDB/) and the Bioinforma......Maintained at the University of Texas Health Science Center at Tyler, Texas, the tmRNA database (tmRDB) is accessible at the URL http://psyche.uthct.edu/dbs/tmRDB/tmRDB.html with mirror sites located at Auburn University, Auburn, Alabama (http......://www.ag.auburn.edu/mirror/tmRDB/) and the Bioinformatics Research Center, Aarhus, Denmark (http://www.bioinf.au.dk/tmRDB/). The tmRDB collects and distributes information relevant to the study of tmRNA. In trans-translation, this molecule combines properties of tRNA and mRNA and binds several proteins to form the tmRNP. Related RNPs are likely...

  11. Accelerated probabilistic inference of RNA structure evolution

    Directory of Open Access Journals (Sweden)

    Holmes Ian

    2005-03-01

    Full Text Available Abstract Background Pairwise stochastic context-free grammars (Pair SCFGs are powerful tools for evolutionary analysis of RNA, including simultaneous RNA sequence alignment and secondary structure prediction, but the associated algorithms are intensive in both CPU and memory usage. The same problem is faced by other RNA alignment-and-folding algorithms based on Sankoff's 1985 algorithm. It is therefore desirable to constrain such algorithms, by pre-processing the sequences and using this first pass to limit the range of structures and/or alignments that can be considered. Results We demonstrate how flexible classes of constraint can be imposed, greatly reducing the computational costs while maintaining a high quality of structural homology prediction. Any score-attributed context-free grammar (e.g. energy-based scoring schemes, or conditionally normalized Pair SCFGs is amenable to this treatment. It is now possible to combine independent structural and alignment constraints of unprecedented general flexibility in Pair SCFG alignment algorithms. We outline several applications to the bioinformatics of RNA sequence and structure, including Waterman-Eggert N-best alignments and progressive multiple alignment. We evaluate the performance of the algorithm on test examples from the RFAM database. Conclusion A program, Stemloc, that implements these algorithms for efficient RNA sequence alignment and structure prediction is available under the GNU General Public License.

  12. A comparison of RNA folding measures

    DEFF Research Database (Denmark)

    Freyhult, E.; Gardner, P. P.; Moulton, V.

    2005-01-01

    the behaviour of these measures over a large range of Rfam ncRNA families. Such measures can be useful in, for example, identifying novel ncRNAs, and indicating the presence of alternate RNA foldings. Results Our analysis shows that ncRNAs, but not mRNAs, in general have lower minimal free energy (MFE) than....... Conclusion Due to the correlations between the different measures we find that it is sufficient to use only two of them in RNA folding studies, one to test if the sequence in question has lower energy than a random sequence with the same dinucleotide frequency (the Z-score) and the other to see......Background In the last few decades there has been a great deal of discussion concerning whether or not noncoding RNA sequences (ncRNAs) fold in a more well-defined manner than random sequences. In this paper, we investigate several existing measures for how well an RNA sequence folds, and compare...

  13. Double Stranded RNA in Human Seminal Plasma

    Directory of Open Access Journals (Sweden)

    Maxim V. Zagoskin

    2017-10-01

    Full Text Available Recently, human semen was shown to contain cell-free nucleic acids, such as DNA, long single stranded RNA, and small RNAs–miRNA and piRNA. The RNAs have been suggested to have potential biological roles as communication molecules between cells and in the temporal and spatial regulation of gene expression in the male reproductive system. Here we demonstrate that human seminal plasma contains a variety of cell-free dsRNAs, describe a robust method to isolate this type of nucleic acid in preparative amounts, and discuss the potential biological roles of these molecules in inheritance. dsRNA plays a role in a variety of biological processes, including gene regulation, is extremely stable and can gain access to cells from the extracellular medium. We suggest that one of the possible functions of dsRNA in human seminal plasma may be to influence human oocytes and therefore, influence the offspring. It also remains possible that these dsRNAs might have potential use as biomarkers for the study of human physiopathological conditions and genetic variation.

  14. A comparison of RNA folding measures

    Directory of Open Access Journals (Sweden)

    Gardner Paul P

    2005-10-01

    Full Text Available Abstract Background In the last few decades there has been a great deal of discussion concerning whether or not noncoding RNA sequences (ncRNAs fold in a more well-defined manner than random sequences. In this paper, we investigate several existing measures for how well an RNA sequence folds, and compare the behaviour of these measures over a large range of Rfam ncRNA families. Such measures can be useful in, for example, identifying novel ncRNAs, and indicating the presence of alternate RNA foldings. Results Our analysis shows that ncRNAs, but not mRNAs, in general have lower minimal free energy (MFE than random sequences with the same dinucleotide frequency. Moreover, even when the MFE is significant, many ncRNAs appear to not have a unique fold, but rather several alternative folds, at least when folded in silico. Furthermore, we find that the six investigated measures are correlated to varying degrees. Conclusion Due to the correlations between the different measures we find that it is sufficient to use only two of them in RNA folding studies, one to test if the sequence in question has lower energy than a random sequence with the same dinucleotide frequency (the Z-score and the other to see if the sequence has a unique fold (the average base-pair distance, D.

  15. Annexin A2 Mediates the Localization of Measles Virus Matrix Protein at the Plasma Membrane.

    Science.gov (United States)

    Koga, Ritsuko; Kubota, Marie; Hashiguchi, Takao; Yanagi, Yusuke; Ohno, Shinji

    2018-02-28

    Annexins are a family of structurally related proteins that bind negatively charged membrane phospholipids in a Ca 2+ -dependent manner. Annexin A2 (AnxA2), a member of the family, has been implicated in a variety of cellular functions including the organization of membrane domains, vesicular trafficking and cell-cell adhesion. AnxA2 generally forms the heterotetrameric complex with a small Ca 2+ -binding protein S100A10. Measles virus (MV), a member of the family Paramyxoviridae , is an enveloped virus with a nonsegmented negative strand RNA genome. Knockdown of AnxA2 greatly reduced MV growth in cells, without affecting its entry and viral RNA production. In MV-infected, AnxA2-knockdown cells, the expression level of the matrix (M) protein, but not other viral proteins, was reduced compared with that in control cells, and the distribution of the M protein at the plasma membrane was decreased. The M protein lines the inner surface of the envelope and plays an important role in virus assembly by connecting the nucleocapsid to the envelope proteins. The M protein bound to AnxA2 independently of AnxA2's phosphorylation or its association with S100A10, and was co-localized with AnxA2 within cells. Truncation of the N-terminal 10 amino acid residues, but not the N-terminal 5 residues, compromised the ability of the M protein to interact with AnxA2 and localize at the plasma membrane. These results indicate that AnxA2 mediates the localization of the MV M protein at the plasma membrane by interacting with its N-terminal region (especially residues at positions 6-10), thereby aiding in MV assembly. IMPORTANCE Measles virus (MV) is an important human pathogen, still claiming ∼ 100,000 lives per year despite the presence of effective vaccines, and causes occasional outbreaks even in developed countries. Replication of viruses largely relies on the functions of host cells. Our study revealed that the reduction of the host protein annexin A2 compromises the replication of

  16. Multiple Regression Analysis of mRNA-miRNA Associations in Colorectal Cancer Pathway

    Science.gov (United States)

    Wang, Fengfeng; Wong, S. C. Cesar; Chan, Lawrence W. C.; Cho, William C. S.; Yip, S. P.; Yung, Benjamin Y. M.

    2014-01-01

    Background. MicroRNA (miRNA) is a short and endogenous RNA molecule that regulates posttranscriptional gene expression. It is an important factor for tumorigenesis of colorectal cancer (CRC), and a potential biomarker for diagnosis, prognosis, and therapy of CRC. Our objective is to identify the related miRNAs and their associations with genes frequently involved in CRC microsatellite instability (MSI) and chromosomal instability (CIN) signaling pathways. Results. A regression model was adopted to identify the significantly associated miRNAs targeting a set of candidate genes frequently involved in colorectal cancer MSI and CIN pathways. Multiple linear regression analysis was used to construct the model and find the significant mRNA-miRNA associations. We identified three significantly associated mRNA-miRNA pairs: BCL2 was positively associated with miR-16 and SMAD4 was positively associated with miR-567 in the CRC tissue, while MSH6 was positively associated with miR-142-5p in the normal tissue. As for the whole model, BCL2 and SMAD4 models were not significant, and MSH6 model was significant. The significant associations were different in the normal and the CRC tissues. Conclusion. Our results have laid down a solid foundation in exploration of novel CRC mechanisms, and identification of miRNA roles as oncomirs or tumor suppressor mirs in CRC. PMID:24895601

  17. mRNA/microRNA gene expression profile in microsatellite unstable colorectal cancer

    Directory of Open Access Journals (Sweden)

    Calin George A

    2007-08-01

    Full Text Available Abstract Background Colorectal cancer develops through two main genetic instability pathways characterized by distinct pathologic features and clinical outcome. Results We investigated colon cancer samples (23 characterized by microsatellite stability, MSS, and 16 by high microsatellite instability, MSI-H for genome-wide expression of microRNA (miRNA and mRNA. Based on combined miRNA and mRNA gene expression, a molecular signature consisting of twenty seven differentially expressed genes, inclusive of 8 miRNAs, could correctly distinguish MSI-H versus MSS colon cancer samples. Among the differentially expressed miRNAs, various members of the oncogenic miR-17-92 family were significantly up-regulated in MSS cancers. The majority of protein coding genes were also up-regulated in MSS cancers. Their functional classification revealed that they were most frequently associated with cell cycle, DNA replication, recombination, repair, gastrointestinal disease and immune response. Conclusion This is the first report that indicates the existence of differences in miRNA expression between MSS versus MSI-H colorectal cancers. In addition, the work suggests that the combination of mRNA/miRNA expression signatures may represent a general approach for improving bio-molecular classification of human cancer.

  18. Phosphatidic acid produced by phospholipase D promotes RNA replication of a plant RNA virus.

    Directory of Open Access Journals (Sweden)

    Kiwamu Hyodo

    2015-05-01

    Full Text Available Eukaryotic positive-strand RNA [(+RNA] viruses are intracellular obligate parasites replicate using the membrane-bound replicase complexes that contain multiple viral and host components. To replicate, (+RNA viruses exploit host resources and modify host metabolism and membrane organization. Phospholipase D (PLD is a phosphatidylcholine- and phosphatidylethanolamine-hydrolyzing enzyme that catalyzes the production of phosphatidic acid (PA, a lipid second messenger that modulates diverse intracellular signaling in various organisms. PA is normally present in small amounts (less than 1% of total phospholipids, but rapidly and transiently accumulates in lipid bilayers in response to different environmental cues such as biotic and abiotic stresses in plants. However, the precise functions of PLD and PA remain unknown. Here, we report the roles of PLD and PA in genomic RNA replication of a plant (+RNA virus, Red clover necrotic mosaic virus (RCNMV. We found that RCNMV RNA replication complexes formed in Nicotiana benthamiana contained PLDα and PLDβ. Gene-silencing and pharmacological inhibition approaches showed that PLDs and PLDs-derived PA are required for viral RNA replication. Consistent with this, exogenous application of PA enhanced viral RNA replication in plant cells and plant-derived cell-free extracts. We also found that a viral auxiliary replication protein bound to PA in vitro, and that the amount of PA increased in RCNMV-infected plant leaves. Together, our findings suggest that RCNMV hijacks host PA-producing enzymes to replicate.

  19. Archaeal rRNA operons, intron splicing and homing endonucleases, RNA polymerase operons and phylogeny

    DEFF Research Database (Denmark)

    Garrett, Roger Antony; Aagaard, Claus Sindbjerg; Andersen, Morten

    1994-01-01

    Over the past decade our laboratory has had a strong interest in defining the phylogenetic status of the archaea. This has involved determining and analysing the sequences of operons of both rRNAs and RNA polymerases and it led to the discovery of the first archaeal rRNA intron. What follows...

  20. A ribonuclease coordinates siRNA amplification and mRNA cleavage during RNAi.

    Science.gov (United States)

    Tsai, Hsin-Yue; Chen, Chun-Chieh G; Conte, Darryl; Moresco, James J; Chaves, Daniel A; Mitani, Shohei; Yates, John R; Tsai, Ming-Daw; Mello, Craig C

    2015-01-29

    Effective silencing by RNA-interference (RNAi) depends on mechanisms that amplify and propagate the silencing signal. In some organisms, small-interfering RNAs (siRNAs) are amplified from target mRNAs by RNA-dependent RNA polymerase (RdRP). Both RdRP recruitment and mRNA silencing require Argonaute proteins, which are generally thought to degrade RNAi targets by directly cleaving them. However, in C. elegans, the enzymatic activity of the primary Argonaute, RDE-1, is not required for silencing activity. We show that RDE-1 can instead recruit an endoribonuclease, RDE-8, to target RNA. RDE-8 can cleave RNA in vitro and is needed for the production of 3' uridylated fragments of target mRNA in vivo. We also find that RDE-8 promotes RdRP activity, thereby ensuring amplification of siRNAs. Together, our findings suggest a model in which RDE-8 cleaves target mRNAs to mediate silencing, while generating 3' uridylated mRNA fragments to serve as templates for the RdRP-directed amplification of the silencing signal. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. RNA damage in biological conflicts and the diversity of responding RNA repair systems

    Science.gov (United States)

    Burroughs, A. Maxwell; Aravind, L.

    2016-01-01

    RNA is targeted in biological conflicts by enzymatic toxins or effectors. A vast diversity of systems which repair or ‘heal’ this damage has only recently become apparent. Here, we summarize the known effectors, their modes of action, and RNA targets before surveying the diverse systems which counter this damage from a comparative genomics viewpoint. RNA-repair systems show a modular organization with extensive shuffling and displacement of the constituent domains; however, a general ‘syntax’ is strongly maintained whereby systems typically contain: a RNA ligase (either ATP-grasp or RtcB superfamilies), nucleotidyltransferases, enzymes modifying RNA-termini for ligation (phosphatases and kinases) or protection (methylases), and scaffold or cofactor proteins. We highlight poorly-understood or previously-uncharacterized repair systems and components, e.g. potential scaffolding cofactors (Rot/TROVE and SPFH/Band-7 modules) with their respective cognate non-coding RNAs (YRNAs and a novel tRNA-like molecule) and a novel nucleotidyltransferase associating with diverse ligases. These systems have been extensively disseminated by lateral transfer between distant prokaryotic and microbial eukaryotic lineages consistent with intense inter-organismal conflict. Components have also often been ‘institutionalized’ for non-conflict roles, e.g. in RNA-splicing and in RNAi systems (e.g. in kinetoplastids) which combine a distinct family of RNA-acting prim-pol domains with DICER-like proteins. PMID:27536007

  2. Capturing microRNA targets using an RNA-induced silencing complex (RISC)-trap approach.

    Science.gov (United States)

    Cambronne, Xiaolu A; Shen, Rongkun; Auer, Paul L; Goodman, Richard H

    2012-12-11

    Identifying targets is critical for understanding the biological effects of microRNA (miRNA) expression. The challenge lies in characterizing the cohort of targets for a specific miRNA, especially when targets are being actively down-regulated in miRNA- RNA-induced silencing complex (RISC)-messengerRNA (mRNA) complexes. We have developed a robust and versatile strategy called RISCtrap to stabilize and purify targets from this transient interaction. Its utility was demonstrated by determining specific high-confidence target datasets for miR-124, miR-132, and miR-181 that contained known and previously unknown transcripts. Two previously unknown miR-132 targets identified with RISCtrap, adaptor protein CT10 regulator of kinase 1 (CRK1) and tight junction-associated protein 1 (TJAP1), were shown to be endogenously regulated by miR-132 in adult mouse forebrain. The datasets, moreover, differed in the number of targets and in the types and frequency of microRNA recognition element (MRE) motifs, thus revealing a previously underappreciated level of specificity in the target sets regulated by individual miRNAs.

  3. Orotidine-Containing RNA: Implications for the Hierarchical Selection (Systems Chemistry Emergence) of RNA.

    Science.gov (United States)

    Kim, Eun-Kyong; Martin, Vincent; Krishnamurthy, Ramanarayanan

    2017-09-12

    The prebiotic synthesis of canonical nucleobases from HCN is a cornerstone for the RNA world hypothesis. However, their role in the primordial pathways to RNA is still debated. The very same process starting from HCN also gives rise to orotic acid, which (via orotidine) plays a crucial role in extant biology in the de novo synthesis of uridine and cytidine, the informational base-pairs in RNA. However, orotidine itself is absent in RNA. Given the prebiotic and biological relevance of orotic acid vis-à-vis uracil, we investigated orotidine-containing RNA oligonucleotides and show that they have severely compromised base-pairing properties. While not unexpected, these results suggest that the emergence of extant RNA cannot just be a consequence of the plausible prebiotic formation of its chemical constituents/building blocks. In combination with other investigations on alternative prebiotic nucleobases, sugars, and linkers, these findings imply that the selection of the components of extant RNA occurred at a higher hierarchical level of an oligomer/polymer based on its functional properties-pointing to a systems chemistry emergence of RNA from a library of precursors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Kinetoplastid guide RNA biogenesis is dependent on subunits of the mitochondrial RNA binding complex 1 and mitochondrial RNA polymerase

    Czech Academy of Sciences Publication Activity Database

    Hashimi, Hassan; Číčová, Zdeňka; Novotná, Lucie; Wen, Y.-Z.; Lukeš, Julius

    2009-01-01

    Roč. 15, č. 4 (2009), s. 588-599 ISSN 1355-8382 R&D Projects: GA ČR GA204/09/1667; GA AV ČR IAA500960705; GA MŠk LC07032; GA MŠk 2B06129; GA ČR GD524/03/H133 Institutional research plan: CEZ:AV0Z60220518 Keywords : RNA editing * guide RNA * mitochondrion * trypanosome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.198, year: 2009

  5. Reproducible pattern of microRNA in normal human skin

    DEFF Research Database (Denmark)

    Holst, Line; Kaczkowski, Bogumil; Gniadecki, Robert

    2010-01-01

    RNA expression pattern in normal human skin. Here we investigated miRNA expression profiles from skin biopsies of 8 healthy volunteers taken from sun protected and mildly photo damaged skin using the modified protocol for miRNA extraction. We were able to show a constant pattern of miRNA expression between......MicroRNAs (miRNAs) regulate cell growth, differentiation and apoptosis via specific targeting of messenger RNA (mRNA). Aberrant mRNA expression contributes to pathological processes such as carcinogenesis. To take advantage of miRNA profiling in skin disease it is essential to investigate mi...... different individuals. We did not find any significant differences in miRNA expression between sun protected and mildly photodamaged skin. These results may be valuable for future design of studies on miRNA expression in skin disease....

  6. Changes in rRNA levels during stress invalidates results from mRNA blotting: Fluorescence in situ rRNA hybridization permits renormalization for estimation of cellular mRNA levels

    DEFF Research Database (Denmark)

    Hansen, M.C.; Nielsen, A.K.; Molin, Søren

    2001-01-01

    obtained by these techniques are compared between experiments in which differences in growth rates, strains, or stress treatments occur, the normalization procedure may have a significant impact on the results. In this report we present a solution to the normalization problem in RNA slot blotting...... the relative level of rRNA per cell, and slot blotting to rRNA probes, which estimates the level of rRNA per extracted total RNA, the amount of RNA per cell was calculated in a series of heat shock experiments with the gram-positive bacterium Lactococcus lactis. It was found that the level of rRNA per cell...... decreased to 30% in the course of the heat shock. This lowered ribosome level led to a decrease in the total RNA content, resulting in a gradually increasing overestimation of the mRNA levels throughout the experiment. Using renormalized cellular mRNA levels, the HrcA-mediated regulation of the genes...

  7. Reproducible pattern of microRNA in normal human skin

    DEFF Research Database (Denmark)

    Holst, Line; Kaczkowski, Bogumil; Gniadecki, Robert

    2010-01-01

    RNA expression pattern in normal human skin. Here we investigated miRNA expression profiles from skin biopsies of 8 healthy volunteers taken from sun protected and mildly photo damaged skin using the modified protocol for miRNA extraction. We were able to show a constant pattern of miRNA expression between...... different individuals. We did not find any significant differences in miRNA expression between sun protected and mildly photodamaged skin. These results may be valuable for future design of studies on miRNA expression in skin disease.......MicroRNAs (miRNAs) regulate cell growth, differentiation and apoptosis via specific targeting of messenger RNA (mRNA). Aberrant mRNA expression contributes to pathological processes such as carcinogenesis. To take advantage of miRNA profiling in skin disease it is essential to investigate mi...

  8. Biochemical characterization of a recombinant Japanese encephalitis virus RNA-dependent RNA polymerase

    Directory of Open Access Journals (Sweden)

    Kim Chan-Mi

    2007-07-01

    Full Text Available Abstract Background Japanese encephalitis virus (JEV NS5 is a viral nonstructural protein that carries both methyltransferase and RNA-dependent RNA polymerase (RdRp domains. It is a key component of the viral RNA replicase complex that presumably includes other viral nonstructural and cellular proteins. The biochemical properties of JEV NS5 have not been characterized due to the lack of a robust in vitro RdRp assay system, and the molecular mechanisms for the initiation of RNA synthesis by JEV NS5 remain to be elucidated. Results To characterize the biochemical properties of JEV RdRp, we expressed in Escherichia coli and purified an enzymatically active full-length recombinant JEV NS5 protein with a hexahistidine tag at the N-terminus. The purified NS5 protein, but not the mutant NS5 protein with an Ala substitution at the first Asp of the RdRp-conserved GDD motif, exhibited template- and primer-dependent RNA synthesis activity using a poly(A RNA template. The NS5 protein was able to use both plus- and minus-strand 3'-untranslated regions of the JEV genome as templates in the absence of a primer, with the latter RNA being a better template. Analysis of the RNA synthesis initiation site using the 3'-end 83 nucleotides of the JEV genome as a minimal RNA template revealed that the NS5 protein specifically initiates RNA synthesis from an internal site, U81, at the two nucleotides upstream of the 3'-end of the template. Conclusion As a first step toward the understanding of the molecular mechanisms for JEV RNA replication and ultimately for the in vitro reconstitution of viral RNA replicase complex, we for the first time established an in vitro JEV RdRp assay system with a functional full-length recombinant JEV NS5 protein and characterized the mechanisms of RNA synthesis from nonviral and viral RNA templates. The full-length recombinant JEV NS5 will be useful for the elucidation of the structure-function relationship of this enzyme and for the

  9. Cancer-Related Triplets of mRNA-lncRNA-miRNA Revealed by Integrative Network in Uterine Corpus Endometrial Carcinoma

    Directory of Open Access Journals (Sweden)

    Chenglin Liu

    2017-01-01

    Full Text Available The regulation of transcriptome expression level is a complex process involving multiple-level interactions among molecules such as protein coding RNA (mRNA, long noncoding RNA (lncRNA, and microRNA (miRNA, which are essential for the transcriptome stability and maintenance and regulation of body homeostasis. The availability of multilevel expression data enables a comprehensive view of the regulatory network. In this study, we analyzed the coding and noncoding gene expression profiles of 301 patients with uterine corpus endometrial carcinoma (UCEC. A new method was proposed to construct a genome-wide integrative network based on variance inflation factor (VIF regression method. The cross-regulation relations of mRNA, lncRNA, and miRNA were then selected based on clique-searching algorithm from the network, when any two molecules of the three were shown as interacting according to the integrative network. Such relation, which we call the mRNA-lncRNA-miRNA triplet, demonstrated the complexity in transcriptome regulation process. Finally, six UCEC-related triplets were selected in which the mRNA participates in endometrial carcinoma pathway, such as CDH1 and TP53. The multi-type RNAs are proved to be cross-regulated as to each of the six triplets according to literature. All the triplets demonstrated the association with the initiation and progression of UCEC. Our method provides a comprehensive strategy for the investigation of transcriptome regulation mechanism.

  10. Pathways of cellular internalisation of liposomes delivered siRNA and effects on siRNA engagement with target mRNA and silencing in cancer cells.

    Science.gov (United States)

    Alshehri, Abdullah; Grabowska, Anna; Stolnik, Snow

    2018-02-28

    Design of an efficient delivery system is a generally recognised bottleneck in translation of siRNA technology into clinic. Despite research efforts, cellular processes that determine efficiency of siRNA silencing achieved by different delivery formulations remain unclear. Here, we investigated the mechanism(s) of cellular internalisation of a model siRNA-loaded liposome system in a correlation to the engagement of delivered siRNA with its target and consequent silencing by adopting siRNA molecular beacon technology. Probing of cellular internalisation pathways by a panel of pharmacological inhibitors indicated that clathrin-mediated (dynamin-dependent) endocytosis, macropinocytosis (dynamine independent), and cell membrane cholesterol dependent process(es) (clathrin and caveolea-independent) all play a role in the siRNA-liposomes internalization. The inhibition of either of these entry routes was, in general, mirrored by a reduction in the level of siRNA engagement with its target mRNA, as well as in a reduction of the target gene silencing. A dramatic increase in siRNA engagement with its target RNA was observed on disruption of endosomal membrane (by chloroquine), accompanied with an increased silencing. The work thus illustrates that employing molecular beacon siRNA technology one can start to assess the target RNA engagement - a stage between initial cellular internalization and final gene silencing of siRNA delivery systems.

  11. RNA 3D modules in genome-wide predictions of RNA 2D structure

    DEFF Research Database (Denmark)

    Theis, Corinna; Zirbel, Craig L; Zu Siederdissen, Christian Höner

    2015-01-01

    . These modules can, for example, occur inside structural elements which in RNA 2D predictions appear as internal loops. Hence one question is if the use of such RNA 3D information can improve the prediction accuracy of RNA secondary structure at a genome-wide level. Here, we use RNAz in combination with 3D......Recent experimental and computational progress has revealed a large potential for RNA structure in the genome. This has been driven by computational strategies that exploit multiple genomes of related organisms to identify common sequences and secondary structures. However, these computational...... approaches have two main challenges: they are computationally expensive and they have a relatively high false discovery rate (FDR). Simultaneously, RNA 3D structure analysis has revealed modules composed of non-canonical base pairs which occur in non-homologous positions, apparently by independent evolution...

  12. A Viral RNA Structural Element Alters Host Recognition of Nonself RNA

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, J. L.; Gardner, C. L.; Kimura, T.; White, J. P.; Liu, G.; Trobaugh, D. W.; Huang, C.; Tonelli, M.; Paessler, S.; Takeda, K.; Klimstra, W. B.; Amarasinghe, G. K.; Diamond, M. S.

    2014-01-30

    Although interferon (IFN) signaling induces genes that limit viral infection, many pathogenic viruses overcome this host response. As an example, 2'-O methylation of the 5' cap of viral RNA subverts mammalian antiviral responses by evading restriction of Ifit1, an IFN-stimulated gene that regulates protein synthesis. However, alphaviruses replicate efficiently in cells expressing Ifit1 even though their genomic RNA has a 5' cap lacking 2'-O methylation. We show that pathogenic alphaviruses use secondary structural motifs within the 5' untranslated region (UTR) of their RNA to alter Ifit1 binding and function. Mutations within the 5'-UTR affecting RNA structural elements enabled restriction by or antagonism of Ifit1 in vitro and in vivo. These results identify an evasion mechanism by which viruses use RNA structural motifs to avoid immune restriction.

  13. C to U RNA editing mediated by APOBEC1 requires RNA-binding protein RBM47.

    Science.gov (United States)

    Fossat, Nicolas; Tourle, Karin; Radziewic, Tania; Barratt, Kristen; Liebhold, Doreen; Studdert, Joshua B; Power, Melinda; Jones, Vanessa; Loebel, David A F; Tam, Patrick P L

    2014-08-01

    Cytidine (C) to Uridine (U) RNA editing is a post-transcriptional modification that is accomplished by the deaminase APOBEC1 and its partnership with the RNA-binding protein A1CF. We identify and characterise here a novel RNA-binding protein, RBM47, that interacts with APOBEC1 and A1CF and is expressed in tissues where C to U RNA editing occurs. RBM47 can substitute for A1CF and is necessary and sufficient for APOBEC1-mediated editing in vitro. Editing is further impaired in Rbm47-deficient mutant mice. These findings suggest that RBM47 and APOBEC1 constitute the basic machinery for C to U RNA editing. © 2014 The Authors.

  14. Clinical significance of LUNX mRNA, CK19 mRNA, CEA mRNA expression in detecting micrometastasis from lung cancer

    International Nuclear Information System (INIS)

    Zhu Guangying; Liu Delin; Chen Jie

    2003-01-01

    Objective: To evaluate the sensitivity, specificity and clinical significance of CK19 mRNA, CEA mRNA and LUNX mRNA for detecting micrometastasis by sampling the peripheral blood and regional lymph nodes of lung cancer patients. Methods: Reverse transcriptase chain reaction (RT-PCR) was used to detect LUNX mRNA, CK19 mRNA, CEA mRNA for micrometastasis by sampling the peripheral blood of 48 lung cancer patients and 44 regional lymph nodes of such patients treated by curative resection. Peripheral blood of 30 patients with pulmonary benign lesions and 10 normal healthy volunteers and lymph nodes of 6 patients with benign pulmonary diseases served as control. Results: 1) LUNX mRNA, CK19 mRNA, CEA mRNA were expressed in all (35/35) lung cancer tissues. 2) In the peripheral blood from 48 lung cancer patients, 30 (62.5%) were positive for LUNX mRNA, 24 (50.0%) positive for CK19 mRNA and 32(66.7%) positive for CEA mRNA. The positive detection rates of micrometastasis in 44 lymph nodes from lung cancer patients were 36.4% (16 out of 44) for LUNX mRNA, 27.3% (12 out of 44) for CK19 mRNA and 40.9% (18 out of 44) for CEA mRNA. 3) In the 30 blood samples from patients with pulmonary benign diseases, 2 (6.7%) expressed CK19 mRNA, but none expressed LUNX mRNA or CEA mRNA. All the 3 molecular markers were negative in the 10 blood samples from healthy volunteers. In 11 lymph nodes from patients with pulmonary benign lesions, none was positive for any of the three markers. 4) In 44 regional lymph nodes from lung cancer patients, 6 (13.6%) were positive for metastasis by histopathological examination, with a positive rate significantly lower than that of the RT-PCR (P<0.05). 5) The micrometastatic positive rate in the peripheral blood of 40 non-small cell lung cancer (NSCLC) patients was significantly related to TNM stage (P=0.01). Conclusions: LUNX mRNA, CK19 MRNA, CEA mRNA are all appropriate target genes for the detection of micrometastasis from lung cancer. LUNX mRNA and CEA mRNA

  15. Human Enterovirus Nonstructural Protein 2CATPase Functions as Both an RNA Helicase and ATP-Independent RNA Chaperone

    Science.gov (United States)

    Xia, Hongjie; Wang, Peipei; Wang, Guang-Chuan; Yang, Jie; Sun, Xianlin; Wu, Wenzhe; Qiu, Yang; Shu, Ting; Zhao, Xiaolu; Yin, Lei; Qin, Cheng-Feng; Hu, Yuanyang; Zhou, Xi

    2015-01-01

    RNA helicases and chaperones are the two major classes of RNA remodeling proteins, which function to remodel RNA structures and/or RNA-protein interactions, and are required for all aspects of RNA metabolism. Although some virus-encoded RNA helicases/chaperones have been predicted or identified, their RNA remodeling activities in vitro and functions in the viral life cycle remain largely elusive. Enteroviruses are a large group of positive-stranded RNA viruses in the Picornaviridae family, which includes numerous important human pathogens. Herein, we report that the nonstructural protein 2CATPase of enterovirus 71 (EV71), which is the major causative pathogen of hand-foot-and-mouth disease and has been regarded as the most important neurotropic enterovirus after poliovirus eradication, functions not only as an RNA helicase that 3′-to-5′ unwinds RNA helices in an adenosine triphosphate (ATP)-dependent manner, but also as an RNA chaperone that destabilizes helices bidirectionally and facilitates strand annealing and complex RNA structure formation independently of ATP. We also determined that the helicase activity is based on the EV71 2CATPase middle domain, whereas the C-terminus is indispensable for its RNA chaperoning activity. By promoting RNA template recycling, 2CATPase facilitated EV71 RNA synthesis in vitro; when 2CATPase helicase activity was impaired, EV71 RNA replication and virion production were mostly abolished in cells, indicating that 2CATPase-mediated RNA remodeling plays a critical role in the enteroviral life cycle. Furthermore, the RNA helicase and chaperoning activities of 2CATPase are also conserved in coxsackie A virus 16 (CAV16), another important enterovirus. Altogether, our findings are the first to demonstrate the RNA helicase and chaperoning activities associated with enterovirus 2CATPase, and our study provides both in vitro and cellular evidence for their potential roles during viral RNA replication. These findings increase our

  16. Pseudogenes regulate parental gene expression via ceRNA network.

    Science.gov (United States)

    An, Yang; Furber, Kendra L; Ji, Shaoping

    2017-01-01

    The concept of competitive endogenous RNA (ceRNA) was first proposed by Salmena and colleagues. Evidence suggests that pseudogene RNAs can act as a 'sponge' through competitive binding of common miRNA, releasing or attenuating repression through sequestering miRNAs away from parental mRNA. In theory, ceRNAs refer to all transcripts such as mRNA, tRNA, rRNA, long non-coding RNA, pseudogene RNA and circular RNA, because all of them may become the targets of miRNA depending on spatiotemporal situation. As binding of miRNA to the target RNA is not 100% complementary, it is possible that one miRNA can bind to multiple target RNAs and vice versa. All RNAs crosstalk through competitively binding to miRNAvia miRNA response elements (MREs) contained within the RNA sequences, thus forming a complex regulatory network. The ratio of a subset of miRNAs to the corresponding number of MREs determines repression strength on a given mRNA translation or stability. An increase in pseudogene RNA level can sequester miRNA and release repression on the parental gene, leading to an increase in parental gene expression. A massive number of transcripts constitute a complicated network that regulates each other through this proposed mechanism, though some regulatory significance may be mild or even undetectable. It is possible that the regulation of gene and pseudogene expression occurring in this manor involves all RNAs bearing common MREs. In this review, we will primarily discuss how pseudogene transcripts regulate expression of parental genes via ceRNA network and biological significance of regulation. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  17. Dissecting the interactions of SERRATE with RNA and DICER-LIKE 1 in Arabidopsis microRNA precursor processing

    KAUST Repository

    Iwata, Yuji; Takahashi, Masateru; Fedoroff, Nina V.; Hamdan, Samir

    2013-01-01

    ). In the present study, we examined primary miRNA precursor (pri-miRNA) processing by highly purified recombinant DCL1 and SE proteins and found that SE is integral to pri-miRNA processing by DCL1. SE stimulates DCL1 cleavage of the pri-miRNA in an ionic strength

  18. Therapeutic miRNA and siRNA: Moving from Bench to Clinic as Next Generation Medicine

    Directory of Open Access Journals (Sweden)

    Chiranjib Chakraborty

    2017-09-01

    Full Text Available In the past few years, therapeutic microRNA (miRNA and small interfering RNA (siRNA are some of the most important biopharmaceuticals that are in commercial space as future medicines. This review summarizes the patents of miRNA- and siRNA-based new drugs, and also provides a snapshot about significant biopharmaceutical companies that are investing for the therapeutic development of miRNA and siRNA molecules. An insightful view about individual siRNA and miRNA drugs has been depicted with their present status, which is gaining attention in the therapeutic landscape. The efforts of the biopharmaceuticals are discussed with the status of their preclinical and/or clinical trials. Here, some of the setbacks have been highlighted during the biopharmaceutical development of miRNA and siRNA as individual therapeutics. Finally, a snapshot is illustrated about pharmacokinetics, pharmacodynamics with absorption, distribution, metabolism, and excretion (ADME, which is the fundamental development process of these therapeutics, as well as the delivery system for miRNA- and siRNA-based drugs. Keywords: miRNA, siRNA, drug development

  19. Flock House virus subgenomic RNA3 is replicated and its replication correlates with transactivation of RNA2

    International Nuclear Information System (INIS)

    Eckerle, Lance D.; Albarino, Cesar G.; Ball, L. Andrew.

    2003-01-01

    The nodavirus Flock House virus has a bipartite genome composed of RNAs 1 and 2, which encode the catalytic component of the RNA-dependent RNA polymerase (RdRp) and the capsid protein precursor, respectively. In addition to catalyzing replication of the viral genome, the RdRp also transcribes from RNA1 a subgenomic RNA3, which is both required for and suppressed by RNA2 replication. Here, we show that in the absence of RNA1 replication, FHV RdRp replicated positive-sense RNA3 transcripts fully and copied negative-sense RNA3 transcripts into positive strands. The two nonstructural proteins encoded by RNA3 were dispensable for replication, but sequences in the 3'-terminal 58 nucleotides were required. RNA3 variants that failed to replicate also failed to transactivate RNA2. These results imply that RNA3 is naturally produced both by transcription from RNA1 and by subsequent RNA1-independent replication and that RNA3 replication may be necessary for transactivation of RNA2

  20. dPORE-miRNA: Polymorphic regulation of microRNA genes

    KAUST Repository

    Schmeier, Sebastian

    2011-02-04

    Background: MicroRNAs (miRNAs) are short non-coding RNA molecules that act as post-transcriptional regulators and affect the regulation of protein-coding genes. Mostly transcribed by PolII, miRNA genes are regulated at the transcriptional level similarly to protein-coding genes. In this study we focus on human miRNAs. These miRNAs are involved in a variety of pathways and can affect many diseases. Our interest is on possible deregulation of the transcription initiation of the miRNA encoding genes, which is facilitated by variations in the genomic sequence of transcriptional control regions (promoters). Methodology: Our aim is to provide an online resource to facilitate the investigation of the potential effects of single nucleotide polymorphisms (SNPs) on miRNA gene regulation. We analyzed SNPs overlapped with predicted transcription factor binding sites (TFBSs) in promoters of miRNA genes. We also accounted for the creation of novel TFBSs due to polymorphisms not present in the reference genome. The resulting changes in the original TFBSs and potential creation of new TFBSs were incorporated into the Dragon Database of Polymorphic Regulation of miRNA genes (dPORE-miRNA). Conclusions: The dPORE-miRNA database enables researchers to explore potential effects of SNPs on the regulation of miRNAs. dPORE-miRNA can be interrogated with regards to: a/miRNAs (their targets, or involvement in diseases, or biological pathways), b/SNPs, or c/transcription factors. dPORE-miRNA can be accessed at http://cbrc.kaust.edu.sa/dpore and http://apps.sanbi.ac.za/dpore/. Its use is free for academic and non-profit users. © 2011 Schmeier et al.

  1. Automated classification of RNA 3D motifs and the RNA 3D Motif Atlas

    Science.gov (United States)

    Petrov, Anton I.; Zirbel, Craig L.; Leontis, Neocles B.

    2013-01-01

    The analysis of atomic-resolution RNA three-dimensional (3D) structures reveals that many internal and hairpin loops are modular, recurrent, and structured by conserved non-Watson–Crick base pairs. Structurally similar loops define RNA 3D motifs that are conserved in homologous RNA molecules, but can also occur at nonhomologous sites in diverse RNAs, and which often vary in sequence. To further our understanding of RNA motif structure and sequence variability and to provide a useful resource for structure modeling and prediction, we present a new method for automated classification of internal and hairpin loop RNA 3D motifs and a new online database called the RNA 3D Motif Atlas. To classify the motif instances, a representative set of internal and hairpin loops is automatically extracted from a nonredundant list of RNA-containing PDB files. Their structures are compared geometrically, all-against-all, using the FR3D program suite. The loops are clustered into motif groups, taking into account geometric similarity and structural annotations and making allowance for a variable number of bulged bases. The automated procedure that we have implemented identifies all hairpin and internal loop motifs previously described in the literature. All motif instances and motif groups are assigned unique and stable identifiers and are made available in the RNA 3D Motif Atlas (http://rna.bgsu.edu/motifs), which is automatically updated every four weeks. The RNA 3D Motif Atlas provides an interactive user interface for exploring motif diversity and tools for programmatic data access. PMID:23970545

  2. dPORE-miRNA: Polymorphic regulation of microRNA genes

    KAUST Repository

    Schmeier, Sebastian; Schaefer, Ulf; MacPherson, Cameron R.; Bajic, Vladimir B.

    2011-01-01

    Background: MicroRNAs (miRNAs) are short non-coding RNA molecules that act as post-transcriptional regulators and affect the regulation of protein-coding genes. Mostly transcribed by PolII, miRNA genes are regulated at the transcriptional level similarly to protein-coding genes. In this study we focus on human miRNAs. These miRNAs are involved in a variety of pathways and can affect many diseases. Our interest is on possible deregulation of the transcription initiation of the miRNA encoding genes, which is facilitated by variations in the genomic sequence of transcriptional control regions (promoters). Methodology: Our aim is to provide an online resource to facilitate the investigation of the potential effects of single nucleotide polymorphisms (SNPs) on miRNA gene regulation. We analyzed SNPs overlapped with predicted transcription factor binding sites (TFBSs) in promoters of miRNA genes. We also accounted for the creation of novel TFBSs due to polymorphisms not present in the reference genome. The resulting changes in the original TFBSs and potential creation of new TFBSs were incorporated into the Dragon Database of Polymorphic Regulation of miRNA genes (dPORE-miRNA). Conclusions: The dPORE-miRNA database enables researchers to explore potential effects of SNPs on the regulation of miRNAs. dPORE-miRNA can be interrogated with regards to: a/miRNAs (their targets, or involvement in diseases, or biological pathways), b/SNPs, or c/transcription factors. dPORE-miRNA can be accessed at http://cbrc.kaust.edu.sa/dpore and http://apps.sanbi.ac.za/dpore/. Its use is free for academic and non-profit users. © 2011 Schmeier et al.

  3. Potyviral VPg enhances viral RNA Translation and inhibits reporter mRNA translation in planta.

    Science.gov (United States)

    Eskelin, Katri; Hafrén, Anders; Rantalainen, Kimmo I; Mäkinen, Kristiina

    2011-09-01

    Viral protein genome-linked (VPg) plays a central role in several stages of potyvirus infection. This study sought to answer questions about the role of Potato virus A (PVA; genus Potyvirus) VPg in viral and host RNA expression. When expressed in Nicotiana benthamiana leaves in trans, a dual role of VPg in translation is observed. It repressed the expression of monocistronic luciferase (luc) mRNA and simultaneously induced a significant upregulation in the expression of both replicating and nonreplicating PVA RNAs. This enhanced viral gene expression was due at least to the 5' untranslated region (UTR) of PVA RNA, eukaryotic initiation factors 4E and iso 4E [eIF4E/eIF(iso)4E], and the presence of a sufficient amount of VPg. Coexpression of VPg with viral RNA increased the viral RNA amount, which was not the case with the monocistronic mRNA. Both mutations at certain lysine residues in PVA VPg and eIF4E/eIF(iso)4E depletion reduced its ability to upregulate the viral RNA expression. These modifications were also involved in VPg-mediated downregulation of monocistronic luc expression. These results suggest that VPg can titrate eIF4Es from capped monocistronic RNAs. Because VPg-mediated enhancement of viral gene expression required eIF4Es, it is possible that VPg directs eIF4Es to promote viral RNA expression. From this study it is evident that VPg can serve as a specific regulator of PVA expression by boosting the viral RNA amounts as well as the accumulation of viral translation products. Such a mechanism could function to protect viral RNA from being degraded and to secure efficient production of coat protein (CP) for virion formation.

  4. Potyviral VPg Enhances Viral RNA Translation and Inhibits Reporter mRNA Translation In Planta▿

    Science.gov (United States)

    Eskelin, Katri; Hafrén, Anders; Rantalainen, Kimmo I.; Mäkinen, Kristiina

    2011-01-01

    Viral protein genome-linked (VPg) plays a central role in several stages of potyvirus infection. This study sought to answer questions about the role of Potato virus A (PVA; genus Potyvirus) VPg in viral and host RNA expression. When expressed in Nicotiana benthamiana leaves in trans, a dual role of VPg in translation is observed. It repressed the expression of monocistronic luciferase (luc) mRNA and simultaneously induced a significant upregulation in the expression of both replicating and nonreplicating PVA RNAs. This enhanced viral gene expression was due at least to the 5′ untranslated region (UTR) of PVA RNA, eukaryotic initiation factors 4E and iso 4E [eIF4E/eIF(iso)4E], and the presence of a sufficient amount of VPg. Coexpression of VPg with viral RNA increased the viral RNA amount, which was not the case with the monocistronic mRNA. Both mutations at certain lysine residues in PVA VPg and eIF4E/eIF(iso)4E depletion reduced its ability to upregulate the viral RNA expression. These modifications were also involved in VPg-mediated downregulation of monocistronic luc expression. These results suggest that VPg can titrate eIF4Es from capped monocistronic RNAs. Because VPg-mediated enhancement of viral gene expression required eIF4Es, it is possible that VPg directs eIF4Es to promote viral RNA expression. From this study it is evident that VPg can serve as a specific regulator of PVA expression by boosting the viral RNA amounts as well as the accumulation of viral translation products. Such a mechanism could function to protect viral RNA from being degraded and to secure efficient production of coat protein (CP) for virion formation. PMID:21697470

  5. Human Milk MicroRNA and Total RNA Differ Depending on Milk Fractionation.

    Science.gov (United States)

    Alsaweed, Mohammed; Hepworth, Anna R; Lefèvre, Christophe; Hartmann, Peter E; Geddes, Donna T; Hassiotou, Foteini

    2015-10-01

    MicroRNA have been recently discovered in human milk signifying potentially important functions for both the lactating breast and the infant. Whilst human milk microRNA have started to be explored, little data exist on the evaluation of sample processing, and analysis to ensure that a full spectrum of microRNA can be obtained. Human milk comprises three main fractions: cells, skim milk, and lipids. Typically, the skim milk fraction has been measured in isolation despite evidence that the lipid fraction may contain more microRNA. This study aimed to standardize isolation of microRNA and total RNA from all three fractions of human milk to determine the most appropriate sampling and analysis procedure for future studies. Three different methods from eight commercially available kits were tested for their efficacy in extracting total RNA and microRNA from the lipid, skim, and cell fractions of human milk. Each fraction yielded different concentrations of RNA and microRNA, with the highest quantities found in the cell and lipid fractions, and the lowest in skim milk. The column-based phenol-free method was the most efficient extraction method for all three milk fractions. Two microRNAs were expressed and validated in the three milk fractions by qPCR using the three recommended extraction kits for each fraction. High expression levels were identified in the skim and lipid milk factions for these microRNAs. These results suggest that careful consideration of both the human milk sample preparation and extraction protocols should be made prior to embarking upon research in this area. © 2015 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc.

  6. Identifying functional cancer-specific miRNA-mRNA interactions in testicular germ cell tumor.

    Science.gov (United States)

    Sedaghat, Nafiseh; Fathy, Mahmood; Modarressi, Mohammad Hossein; Shojaie, Ali

    2016-09-07

    Testicular cancer is the most common cancer in men aged between 15 and 35 and more than 90% of testicular neoplasms are originated at germ cells. Recent research has shown the impact of microRNAs (miRNAs) in different types of cancer, including testicular germ cell tumor (TGCT). MicroRNAs are small non-coding RNAs which affect the development and progression of cancer cells by binding to mRNAs and regulating their expressions. The identification of functional miRNA-mRNA interactions in cancers, i.e. those that alter the expression of genes in cancer cells, can help delineate post-regulatory mechanisms and may lead to new treatments to control the progression of cancer. A number of sequence-based methods have been developed to predict miRNA-mRNA interactions based on the complementarity of sequences. While necessary, sequence complementarity is, however, not sufficient for presence of functional interactions. Alternative methods have thus been developed to refine the sequence-based interactions using concurrent expression profiles of miRNAs and mRNAs. This study aims to find functional cancer-specific miRNA-mRNA interactions in TGCT. To this end, the sequence-based predicted interactions are first refined using an ensemble learning method, based on two well-known methods of learning miRNA-mRNA interactions, namely, TaLasso and GenMiR++. Additional functional analyses were then used to identify a subset of interactions to be most likely functional and specific to TGCT. The final list of 13 miRNA-mRNA interactions can be potential targets for identifying TGCT-specific interactions and future laboratory experiments to develop new therapies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Deep sequencing of cardiac microRNA-mRNA interactomes in clinical and experimental cardiomyopathy.

    Science.gov (United States)

    Matkovich, Scot J; Dorn, Gerald W

    2015-01-01

    MicroRNAs are a family of short (~21 nucleotide) noncoding RNAs that serve key roles in cellular growth and differentiation and the response of the heart to stress stimuli. As the sequence-specific recognition element of RNA-induced silencing complexes (RISCs), microRNAs bind mRNAs and prevent their translation via mechanisms that may include transcript degradation and/or prevention of ribosome binding. Short microRNA sequences and the ability of microRNAs to bind to mRNA sites having only partial/imperfect sequence complementarity complicate purely computational analyses of microRNA-mRNA interactomes. Furthermore, computational microRNA target prediction programs typically ignore biological context, and therefore the principal determinants of microRNA-mRNA binding: the presence and quantity of each. To address these deficiencies we describe an empirical method, developed via studies of stressed and failing hearts, to determine disease-induced changes in microRNAs, mRNAs, and the mRNAs targeted to the RISC, without cross-linking mRNAs to RISC proteins. Deep sequencing methods are used to determine RNA abundances, delivering unbiased, quantitative RNA data limited only by their annotation in the genome of interest. We describe the laboratory bench steps required to perform these experiments, experimental design strategies to achieve an appropriate number of sequencing reads per biological replicate, and computer-based processing tools and procedures to convert large raw sequencing data files into gene expression measures useful for differential expression analyses.

  8. SR proteins are NXF1 adaptors that link alternative RNA processing to mRNA export.

    Science.gov (United States)

    Müller-McNicoll, Michaela; Botti, Valentina; de Jesus Domingues, Antonio M; Brandl, Holger; Schwich, Oliver D; Steiner, Michaela C; Curk, Tomaz; Poser, Ina; Zarnack, Kathi; Neugebauer, Karla M

    2016-03-01

    Nuclear export factor 1 (NXF1) exports mRNA to the cytoplasm after recruitment to mRNA by specific adaptor proteins. How and why cells use numerous different export adaptors is poorly understood. Here we critically evaluate members of the SR protein family (SRSF1-7) for their potential to act as NXF1 adaptors that couple pre-mRNA processing to mRNA export. Consistent with this proposal, >1000 endogenous mRNAs required individual SR proteins for nuclear export in vivo. To address the mechanism, transcriptome-wide RNA-binding profiles of NXF1 and SRSF1-7 were determined in parallel by individual-nucleotide-resolution UV cross-linking and immunoprecipitation (iCLIP). Quantitative comparisons of RNA-binding sites showed that NXF1 and SR proteins bind mRNA targets at adjacent sites, indicative of cobinding. SRSF3 emerged as the most potent NXF1 adaptor, conferring sequence specificity to RNA binding by NXF1 in last exons. Interestingly, SRSF3 and SRSF7 were shown to bind different sites in last exons and regulate 3' untranslated region length in an opposing manner. Both SRSF3 and SRSF7 promoted NXF1 recruitment to mRNA. Thus, SRSF3 and SRSF7 couple alternative splicing and polyadenylation to NXF1-mediated mRNA export, thereby controlling the cytoplasmic abundance of transcripts with alternative 3' ends. © 2016 Müller-McNicoll et al.; Published by Cold Spring Harbor Laboratory Press.

  9. RNA interference in designing transgenic crops.

    Science.gov (United States)

    Ali, Nusrat; Datta, Swapan K; Datta, Karabi

    2010-01-01

    RNA interference (RNAi) is a sequence specific gene silencing mechanism, triggered by the introduction of dsRNA leading to mRNA degradation. It helps in switching on and off the targeted gene, which might have significant impact in developmental biology. Discovery of RNAi represents one of the most promising and rapidly advancing frontiers in plant functional genomics and in crop improvement by plant metabolic engineering and also plays an important role in reduction of allergenicity by silencing specific plant allergens. In plants the RNAi technology has been employed successfully in improvement of several plant species- by increasing their nutritional value, overall quality and by conferring resistance against pathogens and diseases. The review gives an insight to the perspective use of the technology in designing crops with innovation, to bring improvement to crop productivity and quality.

  10. Nonviral pulmonary delivery of siRNA.

    Science.gov (United States)

    Merkel, Olivia M; Kissel, Thomas

    2012-07-17

    RNA interference (RNAi) is an important part of the cell's defenses against viruses and other foreign genes. Moreover, the biotechnological exploitation of RNAi offers therapeutic potential for a range of diseases for which drugs are currently unavailable. Unfortunately, the small interfering RNAs (siRNAs) that are central to RNAi in the cytoplasm are readily degradable by ubiquitous nucleases, are inefficiently targeted to desired organs and cell types, and are excreted quickly upon systemic injection. As a result, local administration techniques have been favored over the past few years, resulting in great success in the treatment of viral infections and other respiratory disorders. Because there are several advantages of pulmonary delivery over systemic administration, two of the four siRNA drugs currently in phase II clinical trials are delivered intranasally or by inhalation. The air-blood barrier, however, has only limited permeability toward large, hydrophilic biopharmaceuticals such as nucleic acids; in addition, the lung imposes intrinsic hurdles to efficient siRNA delivery. Thus, appropriate formulations and delivery devices are very much needed. Although many different formulations have been optimized for in vitro siRNA delivery to lung cells, only a few have been reported successful in vivo. In this Account, we discuss both obstacles to pulmonary siRNA delivery and the success stories that have been achieved thus far. The optimal pulmonary delivery vehicle should be neither cytotoxic nor immunogenic, should protect the payload from degradation by nucleases during the delivery process, and should mediate the intracellular uptake of siRNA. Further requirements include the improvement of the pharmacokinetics and lung distribution profiles of siRNA, the extension of lung retention times (through reduced recognition by macrophages), and the incorporation of reversible or stimuli-responsive binding of siRNA to allow for efficient release of the siRNAs at the

  11. RCrane: semi-automated RNA model building.

    Science.gov (United States)

    Keating, Kevin S; Pyle, Anna Marie

    2012-08-01

    RNA crystals typically diffract to much lower resolutions than protein crystals. This low-resolution diffraction results in unclear density maps, which cause considerable difficulties during the model-building process. These difficulties are exacerbated by the lack of computational tools for RNA modeling. Here, RCrane, a tool for the partially automated building of RNA into electron-density maps of low or intermediate resolution, is presented. This tool works within Coot, a common program for macromolecular model building. RCrane helps crystallographers to place phosphates and bases into electron density and then automatically predicts and builds the detailed all-atom structure of the traced nucleotides. RCrane then allows the crystallographer to review the newly built structure and select alternative backbone conformations where desired. This tool can also be used to automatically correct the backbone structure of previously built nucleotides. These automated corrections can fix incorrect sugar puckers, steric clashes and other structural problems.

  12. Molecular computation: RNA solutions to chess problems.

    Science.gov (United States)

    Faulhammer, D; Cukras, A R; Lipton, R J; Landweber, L F

    2000-02-15

    We have expanded the field of "DNA computers" to RNA and present a general approach for the solution of satisfiability problems. As an example, we consider a variant of the "Knight problem," which asks generally what configurations of knights can one place on an n x n chess board such that no knight is attacking any other knight on the board. Using specific ribonuclease digestion to manipulate strands of a 10-bit binary RNA library, we developed a molecular algorithm and applied it to a 3 x 3 chessboard as a 9-bit instance of this problem. Here, the nine spaces on the board correspond to nine "bits" or placeholders in a combinatorial RNA library. We recovered a set of "winning" molecules that describe solutions to this problem.

  13. Bioinformatics of cardiovascular miRNA biology.

    Science.gov (United States)

    Kunz, Meik; Xiao, Ke; Liang, Chunguang; Viereck, Janika; Pachel, Christina; Frantz, Stefan; Thum, Thomas; Dandekar, Thomas

    2015-12-01

    MicroRNAs (miRNAs) are small ~22 nucleotide non-coding RNAs and are highly conserved among species. Moreover, miRNAs regulate gene expression of a large number of genes associated with important biological functions and signaling pathways. Recently, several miRNAs have been found to be associated with cardiovascular diseases. Thus, investigating the complex regulatory effect of miRNAs may lead to a better understanding of their functional role in the heart. To achieve this, bioinformatics approaches have to be coupled with validation and screening experiments to understand the complex interactions of miRNAs with the genome. This will boost the subsequent development of diagnostic markers and our understanding of the physiological and therapeutic role of miRNAs in cardiac remodeling. In this review, we focus on and explain different bioinformatics strategies and algorithms for the identification and analysis of miRNAs and their regulatory elements to better understand cardiac miRNA biology. Starting with the biogenesis of miRNAs, we present approaches such as LocARNA and miRBase for combining sequence and structure analysis including phylogenetic comparisons as well as detailed analysis of RNA folding patterns, functional target prediction, signaling pathway as well as functional analysis. We also show how far bioinformatics helps to tackle the unprecedented level of complexity and systemic effects by miRNA, underlining the strong therapeutic potential of miRNA and miRNA target structures in cardiovascular disease. In addition, we discuss drawbacks and limitations of bioinformatics algorithms and the necessity of experimental approaches for miRNA target identification. This article is part of a Special Issue entitled 'Non-coding RNAs'. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. The Conserved RNA Exonuclease Rexo5 Is Required for 3′ End Maturation of 28S rRNA, 5S rRNA, and snoRNAs

    Directory of Open Access Journals (Sweden)

    Stefanie Gerstberger

    2017-10-01

    Full Text Available Non-coding RNA biogenesis in higher eukaryotes has not been fully characterized. Here, we studied the Drosophila melanogaster Rexo5 (CG8368 protein, a metazoan-specific member of the DEDDh 3′-5′ single-stranded RNA exonucleases, by genetic, biochemical, and RNA-sequencing approaches. Rexo5 is required for small nucleolar RNA (snoRNA and rRNA biogenesis and is essential in D. melanogaster. Loss-of-function mutants accumulate improperly 3′ end-trimmed 28S rRNA, 5S rRNA, and snoRNA precursors in vivo. Rexo5 is ubiquitously expressed at low levels in somatic metazoan cells but extremely elevated in male and female germ cells. Loss of Rexo5 leads to increased nucleolar size, genomic instability, defective ribosome subunit export, and larval death. Loss of germline expression compromises gonadal growth and meiotic entry during germline development.

  15. Identification of RNA molecules by specific enzyme digestion and mass spectrometry: software for and implementation of RNA mass mapping

    DEFF Research Database (Denmark)

    Matthiesen, Rune; Kirpekar, Finn

    2009-01-01

    The idea of identifying or characterizing an RNA molecule based on a mass spectrum of specifically generated RNA fragments has been used in various forms for well over a decade. We have developed software-named RRM for 'RNA mass mapping'-which can search whole prokaryotic genomes or RNA FASTA...... sequence databases to identify the origin of a given RNA based on a mass spectrum of RNA fragments. As input, the program uses the masses of specific RNase cleavage of the RNA under investigation. RNase T1 digestion is used here as a demonstration of the usability of the method for RNA identification....... The concept for identification is that the masses of the digestion products constitute a specific fingerprint, which characterize the given RNA. The search algorithm is based on the same principles as those used in peptide mass fingerprinting, but has here been extended to work for both RNA sequence databases...

  16. Cytochrome c oxidase subunit 1-based human RNA quantification to enhance mRNA profiling in forensic biology

    Directory of Open Access Journals (Sweden)

    Dong Zhao

    2017-01-01

    Full Text Available RNA analysis offers many potential applications in forensic science, and molecular identification of body fluids by analysis of cell-specific RNA markers represents a new technique for use in forensic cases. However, due to the nature of forensic materials that often admixed with nonhuman cellular components, human-specific RNA quantification is required for the forensic RNA assays. Quantification assay for human RNA has been developed in the present study with respect to body fluid samples in forensic biology. The quantitative assay is based on real-time reverse transcription-polymerase chain reaction of mitochondrial RNA cytochrome c oxidase subunit I and capable of RNA quantification with high reproducibility and a wide dynamic range. The human RNA quantification improves the quality of mRNA profiling in the identification of body fluids of saliva and semen because the quantification assay can exclude the influence of nonhuman components and reduce the adverse affection from degraded RNA fragments.

  17. Neutral Polymeric Micelles for RNA Delivery

    Science.gov (United States)

    Lundy, Brittany B.; Convertine, Anthony; Miteva, Martina; Stayton, Patrick S.

    2013-01-01

    RNA interference (RNAi) drugs have significant therapeutic potential but delivery systems with appropriate efficacy and toxicity profiles are still needed. Here, we describe a neutral, ampholytic polymeric delivery system based on conjugatable diblock polymer micelles. The diblock copolymer contains a hydrophilic poly[N-(2-hydroxypropyl) methacrylamide-co-N-(2-(pyridin-2- yldisulfanyl)ethyl)methacrylamide) (poly[HPMA-co-PDSMA]) segment to promote aqueous stability and facilitate thiol-disulfide exchange reactions, and a second ampholytic block composed of propyl acrylic acid (PAA), dimethylaminoethyl methacrylate (DMAEMA), and butyl methacrylate (BMA). The poly[(HPMA-co-PDSMA)-b-(PAA-co-DMAEMA-co-BMA)] was synthesized using Reversible Addition-Fragmentation chain Transfer (RAFT) polymerization with an overall molecular weight of 22,000 g/mol and a PDI of 1.88. Dynamic light scattering and fluorescence measurements indicated that the diblock copolymers self-assemble under aqueous conditions to form polymeric micelles with a hydrodynamic radius and critical micelle concentration of 25 nm and 25 μg/mL respectively. Red blood cell hemolysis experiments show that the neutral hydrophilic micelles have potent membrane destabilizing activity at endosomal pH values. Thiolated siRNA targeting glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was directly conjugated to the polymeric micelles via thiol exchange reactions with the pyridal disulfide groups present in the micelle corona. Maximum silencing activity in HeLa cells was observed at a 1:10 molar ratio of siRNA to polymer following a 48 h incubation period. Under these conditions 90 % mRNA knockdown and 65 % and protein knockdown of at 48 h was achieved with negligible toxicity. In contrast the polymeric micelles lacking a pH-responsive endosomalytic segment demonstrated negligible mRNA and protein knockdown under these conditions. The potent mRNA knockdown and excellent biocompatibility of the neutral siRNA conjugates

  18. External RNA Controls Consortium Beta Version Update.

    Science.gov (United States)

    Lee, Hangnoh; Pine, P Scott; McDaniel, Jennifer; Salit, Marc; Oliver, Brian

    2016-01-01

    Spike-in RNAs are valuable controls for a variety of gene expression measurements. The External RNA Controls Consortium developed test sets that were used in a number of published reports. Here we provide an authoritative table that summarizes, updates, and corrects errors in the test version that ultimately resulted in the certified Standard Reference Material 2374. We have noted existence of anti-sense RNA controls in the material, corrected sub-pool memberships, and commented on control RNAs that displayed inconsistent behavior.

  19. A lncRNA to repair DNA

    DEFF Research Database (Denmark)

    Lukas, Jiri; Altmeyer, Matthias

    2015-01-01

    Long non-coding RNAs (lncRNAs) have emerged as regulators of various biological processes, but to which extent lncRNAs play a role in genome integrity maintenance is not well understood. In this issue of EMBO Reports, Sharma et al [1] identify the DNA damage-induced lncRNA DDSR1 as an integral...... player of the DNA damage response (DDR). DDSR1 has both an early role by modulating repair pathway choices, and a later function when it regulates gene expression. Sharma et al [1] thus uncover a dual role for a hitherto uncharacterized lncRNA during the cellular response to DNA damage....

  20. The art of editing RNA structural alignments

    DEFF Research Database (Denmark)

    Andersen, Ebbe Sloth

    2014-01-01

    Manual editing of RNA structural alignments may be considered more art than science, since it still requires an expert biologist to take multiple levels of information into account and be slightly creative when constructing high-quality alignments. Even though the task is rather tedious, it is re......Manual editing of RNA structural alignments may be considered more art than science, since it still requires an expert biologist to take multiple levels of information into account and be slightly creative when constructing high-quality alignments. Even though the task is rather tedious...

  1. Prediction of miRNA-mRNA associations in Alzheimer's disease mice using network topology.

    Science.gov (United States)

    Noh, Haneul; Park, Charny; Park, Soojun; Lee, Young Seek; Cho, Soo Young; Seo, Hyemyung

    2014-08-03

    Little is known about the relationship between miRNA and mRNA expression in Alzheimer's disease (AD) at early- or late-symptomatic stages. Sequence-based target prediction algorithms and anti-correlation profiles have been applied to predict miRNA targets using omics data, but this approach often leads to false positive predictions. Here, we applied the joint profiling analysis of mRNA and miRNA expression levels to Tg6799 AD model mice at 4 and 8 months of age using a network topology-based method. We constructed gene regulatory networks and used the PageRank algorithm to predict significant interactions between miRNA and mRNA. In total, 8 cluster modules were predicted by the transcriptome data for co-expression networks of AD pathology. In total, 54 miRNAs were identified as being differentially expressed in AD. Among these, 50 significant miRNA-mRNA interactions were predicted by integrating sequence target prediction, expression analysis, and the PageRank algorithm. We identified a set of miRNA-mRNA interactions that were changed in the hippocampus of Tg6799 AD model mice. We determined the expression levels of several candidate genes and miRNA. For functional validation in primary cultured neurons from Tg6799 mice (MT) and littermate (LM) controls, the overexpression of ARRDC3 enhanced PPP1R3C expression. ARRDC3 overexpression showed the tendency to decrease the expression of miR139-5p and miR3470a in both LM and MT primary cells. Pathological environment created by Aβ treatment increased the gene expression of PPP1R3C and Sfpq but did not significantly alter the expression of miR139-5p or miR3470a. Aβ treatment increased the promoter activity of ARRDC3 gene in LM primary cells but not in MT primary cells. Our results demonstrate AD-specific changes in the miRNA regulatory system as well as the relationship between the expression levels of miRNAs and their targets in the hippocampus of Tg6799 mice. These data help further our understanding of the function

  2. Changes of microRNA profile and microRNA-mRNA regulatory network in bones of ovariectomized mice.

    Science.gov (United States)

    An, Jee Hyun; Ohn, Jung Hun; Song, Jung Ah; Yang, Jae-Yeon; Park, Hyojung; Choi, Hyung Jin; Kim, Sang Wan; Kim, Seong Yeon; Park, Woog-Yang; Shin, Chan Soo

    2014-03-01

    Growing evidence shows the possibility of a role of microRNAs (miRNA) in regulating bone mass. We investigated the change of miRNAs and mRNA expression profiles in bone tissue in an ovariectomized mice model and evaluated the regulatory mechanism of bone mass mediated by miRNAs in an estrogen-deficiency state. Eight-week-old female C3H/HeJ mice underwent ovariectomy (OVX) or sham operation (Sham-op), and their femur and tibia were harvested to extract total bone RNAs after 4 weeks for microarray analysis. Eight miRNAs (miR-127, -133a, -133a*, -133b, -136, -206, -378, -378*) were identified to be upregulated after OVX, whereas one miRNA (miR-204) was downregulated. Concomitant analysis of mRNA microarray revealed that 658 genes were differentially expressed between OVX and Sham-op mice. Target prediction of differentially expressed miRNAs identified potential targets, and integrative analysis using the mRNA microarray results showed that PPARγ and CREB pathways are activated in skeletal tissues after ovariectomy. Among the potential candidates of miRNA, we further studied the role of miR-127 in vitro, which exhibited the greatest changes after OVX. We also studied the effects of miR-136, which has not been studied in the context of bone mass regulation. Transfection of miR-127 inhibitor has enhanced osteoblastic differentiation in UAMS-32 cells as measured by alkaline phosphatase activities and mRNA expression of osteoblast-specific genes, whereas miR-136 precursor has inhibited osteoblastic differentiation. Furthermore, transfection of both miR-127 and miR-136 inhibitors enhanced the osteocyte-like morphological changes and survival in MLO-Y4 cells, whereas precursors of miR-127 and -136 have aggravated dexamethasone-induced cell death. Both of the precursors enhanced osteoclastic differentiation in bone marrow macrophages, indicating that both miR-127 and -136 are negatively regulating bone mass. Taken together, these results suggest a novel insight into the

  3. An enhanced computational platform for investigating the roles of regulatory RNA and for identifying functional RNA motifs

    OpenAIRE

    Chang, Tzu-Hao; Huang, Hsi-Yuan; Hsu, Justin Bo-Kai; Weng, Shun-Long; Horng, Jorng-Tzong; Huang, Hsien-Da

    2013-01-01

    Background Functional RNA molecules participate in numerous biological processes, ranging from gene regulation to protein synthesis. Analysis of functional RNA motifs and elements in RNA sequences can obtain useful information for deciphering RNA regulatory mechanisms. Our previous work, RegRNA, is widely used in the identification of regulatory motifs, and this work extends it by incorporating more comprehensive and updated data sources and analytical approaches into a new platform. Methods ...

  4. Hepatitis C virus translation preferentially depends on active RNA replication.

    Directory of Open Access Journals (Sweden)

    Helene Minyi Liu

    Full Text Available Hepatitis C virus (HCV RNA initiates its replication on a detergent-resistant membrane structure derived from the endoplasmic reticulum (ER in the HCV replicon cells. By performing a pulse-chase study of BrU-labeled HCV RNA, we found that the newly-synthesized HCV RNA traveled along the anterograde-membrane traffic and moved away from the ER. Presumably, the RNA moved to the site of translation or virion assembly in the later steps of viral life cycle. In this study, we further addressed how HCV RNA translation was regulated by HCV RNA trafficking. When the movement of HCV RNA from the site of RNA synthesis to the Golgi complex was blocked by nocodazole, an inhibitor of ER-Golgi transport, HCV protein translation was surprisingly enhanced, suggesting that the translation of viral proteins occurred near the site of RNA synthesis. We also found that the translation of HCV proteins was dependent on active RNA synthesis: inhibition of viral RNA synthesis by an NS5B inhibitor resulted in decreased HCV viral protein synthesis even when the total amount of intracellular HCV RNA remained unchanged. Furthermore, the translation activity of the replication-defective HCV replicons or viral RNA with an NS5B mutation was greatly reduced as compared to that of the corresponding wildtype RNA. By performing live cell labeling of newly synthesized HCV RNA and proteins, we further showed that the newly synthesized HCV proteins colocalized with the newly synthesized viral RNA, suggesting that HCV RNA replication and protein translation take place at or near the same site. Our findings together indicate that the translation of HCV RNA is coupled to RNA replication and that the both processes may occur at the same subcellular membrane compartments, which we term the replicasome.

  5. Cigarette smoke exposure-associated alterations to noncoding RNA

    Directory of Open Access Journals (Sweden)

    Matthew Alan Maccani

    2012-04-01

    Full Text Available Environmental exposures vary by timing, severity, and frequency and may have a number of deleterious effects throughout the life course. The period of in utero development, for example, is one of the most crucial stages of development during which adverse environmental exposures can both alter the growth and development of the fetus as well as lead to aberrant fetal programming, increasing disease risk. During fetal development and beyond, the plethora of exposures, including nutrients, drugs, stress, and trauma, influence health, development, and survival. Recent research in environmental epigenetics has investigated the roles of environmental exposures in influencing epigenetic modes of gene regulation during pregnancy and at various stages of life. Many relatively common environmental exposures, such as cigarette smoking, alcohol consumption, and drug use, may have consequences for the expression and function of noncoding RNA (ncRNA, important post-transcriptional regulators of gene expression. A number of ncRNA have been discovered, including microRNA (miRNA, Piwi-interacting RNA (piRNA, and long noncoding RNA (long ncRNA. The best-characterized species of ncRNA are miRNA, the mature forms of which are ~22 nucleotides in length and capable of post-transcriptionally regulating target mRNA utilizing mechanisms based largely on the degree of complementarity between miRNA and target mRNA. Because miRNA can still negatively regulate gene expression when imperfectly base-paired with a target mRNA, a single miRNA can have a large number of potential mRNA targets and can regulate many different biological processes critical for health and development. The following review analyzes the current literature detailing links between cigarette smoke exposure and aberrant expression and function of noncoding RNA, assesses how such alterations may have consequences throughout the life course, and proposes future directions for this intriguing field of

  6. Identification of the miRNA-mRNA regulatory network of small cell osteosarcoma based on RNA-seq.

    Science.gov (United States)

    Xie, Lin; Liao, Yedan; Shen, Lida; Hu, Fengdi; Yu, Sunlin; Zhou, Yonghong; Zhang, Ya; Yang, Yihao; Li, Dongqi; Ren, Minyan; Yuan, Zhongqin; Yang, Zuozhang

    2017-06-27

    Small cell osteosarcoma (SCO) is a rare subtype of osteosarcoma characterized by highly aggressive progression and a poor prognosis. The miRNA and mRNA expression profiles of peripheral blood mononuclear cells (PBMCs) were obtained in 3 patients with SCO and 10 healthy individuals using high-throughput RNA-sequencing. We identified 37 dysregulated miRNAs and 1636 dysregulated mRNAs in patients with SCO compared to the healthy controls. Specifically, the 37 dysregulated miRNAs consisted of 27 up-regulated miRNAs and 10 down-regulated miRNAs; the 1636 dysregulated mRNAs consisted of 555 up-regulated mRNAs and 1081 down-regulated mRNAs. The target-genes of miRNAs were predicted, and 1334 negative correlations between miRNAs and mRNAs were used to construct an miRNA-mRNA regulatory network. Dysregulated genes were significantly enriched in pathways related to cancer, mTOR signaling and cell cycle signaling. Specifically, hsa-miR-26b-5p, hsa-miR-221-3p and hsa-miR-125b-2-3p were significantly dysregulated miRNAs and exhibited a high degree of connectivity with target genes. Overall, the expression of dysregulated genes in tumor tissues and peripheral blood samples of patients with SCO measured by quantitative real-time polymerase chain reaction corroborated with our bioinformatics analyses based on the expression profiles of PBMCs from patients with SCO. Thus, hsa-miR-26b-5p, hsa-miR-221-3p and hsa-miR-125b-2-3p may be involved in SCO tumorigenesis.

  7. Avian Metapneumovirus Molecular Biology and Development of Genetically Engineered Vaccines

    Science.gov (United States)

    Avian metapneumovirus (aMPV) is an economically important pathogen of turkeys with a worldwide distribution. aMPV is a member of the genus Metapneumovirus within the subfamily Pneumovirinae of the family Paramyxoviridae. The genome of aMPV is a non-segmented, single-stranded, negative-sense RNA of 1...

  8. Freiburg RNA Tools: a web server integrating INTARNA, EXPARNA and LOCARNA.

    Science.gov (United States)

    Smith, Cameron; Heyne, Steffen; Richter, Andreas S; Will, Sebastian; Backofen, Rolf

    2010-07-01

    The Freiburg RNA tools web server integrates three tools for the advanced analysis of RNA in a common web-based user interface. The tools IntaRNA, ExpaRNA and LocARNA support the prediction of RNA-RNA interaction, exact RNA matching and alignment of RNA, respectively. The Freiburg RNA tools web server and the software packages of the stand-alone tools are freely accessible at http://rna.informatik.uni-freiburg.de.

  9. 2'-O-methylation in mRNA disrupts tRNA decoding during translation elongation.

    Science.gov (United States)

    Choi, Junhong; Indrisiunaite, Gabriele; DeMirci, Hasan; Ieong, Ka-Weng; Wang, Jinfan; Petrov, Alexey; Prabhakar, Arjun; Rechavi, Gideon; Dominissini, Dan; He, Chuan; Ehrenberg, Måns; Puglisi, Joseph D

    2018-03-01

    Chemical modifications of mRNA may regulate many aspects of mRNA processing and protein synthesis. Recently, 2'-O-methylation of nucleotides was identified as a frequent modification in translated regions of human mRNA, showing enrichment in codons for certain amino acids. Here, using single-molecule, bulk kinetics and structural methods, we show that 2'-O-methylation within coding regions of mRNA disrupts key steps in codon reading during cognate tRNA selection. Our results suggest that 2'-O-methylation sterically perturbs interactions of ribosomal-monitoring bases (G530, A1492 and A1493) with cognate codon-anticodon helices, thereby inhibiting downstream GTP hydrolysis by elongation factor Tu (EF-Tu) and A-site tRNA accommodation, leading to excessive rejection of cognate aminoacylated tRNAs in initial selection and proofreading. Our current and prior findings highlight how chemical modifications of mRNA tune the dynamics of protein synthesis at different steps of translation elongation.

  10. Adenylylation of small RNA sequencing adapters using the TS2126 RNA ligase I.

    Science.gov (United States)

    Lama, Lodoe; Ryan, Kevin

    2016-01-01

    Many high-throughput small RNA next-generation sequencing protocols use 5' preadenylylated DNA oligonucleotide adapters during cDNA library preparation. Preadenylylation of the DNA adapter's 5' end frees from ATP-dependence the ligation of the adapter to RNA collections, thereby avoiding ATP-dependent side reactions. However, preadenylylation of the DNA adapters can be costly and difficult. The currently available method for chemical adenylylation of DNA adapters is inefficient and uses techniques not typically practiced in laboratories profiling cellular RNA expression. An alternative enzymatic method using a commercial RNA ligase was recently introduced, but this enzyme works best as a stoichiometric adenylylating reagent rather than a catalyst and can therefore prove costly when several variant adapters are needed or during scale-up or high-throughput adenylylation procedures. Here, we describe a simple, scalable, and highly efficient method for the 5' adenylylation of DNA oligonucleotides using the thermostable RNA ligase 1 from bacteriophage TS2126. Adapters with 3' blocking groups are adenylylated at >95% yield at catalytic enzyme-to-adapter ratios and need not be gel purified before ligation to RNA acceptors. Experimental conditions are also reported that enable DNA adapters with free 3' ends to be 5' adenylylated at >90% efficiency. © 2015 Lama and Ryan; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  11. Intrinsic noise of microRNA-regulated genes and the ceRNA hypothesis.

    Directory of Open Access Journals (Sweden)

    Javad Noorbakhsh

    Full Text Available MicroRNAs are small noncoding RNAs that regulate genes post-transciptionally by binding and degrading target eukaryotic mRNAs. We use a quantitative model to study gene regulation by inhibitory microRNAs and compare it to gene regulation by prokaryotic small non-coding RNAs (sRNAs. Our model uses a combination of analytic techniques as well as computational simulations to calculate the mean-expression and noise profiles of genes regulated by both microRNAs and sRNAs. We find that despite very different molecular machinery and modes of action (catalytic vs stoichiometric, the mean expression levels and noise profiles of microRNA-regulated genes are almost identical to genes regulated by prokaryotic sRNAs. This behavior is extremely robust and persists across a wide range of biologically relevant parameters. We extend our model to study crosstalk between multiple mRNAs that are regulated by a single microRNA and show that noise is a sensitive measure of microRNA-mediated interaction between mRNAs. We conclude by discussing possible experimental strategies for uncovering the microRNA-mRNA interactions and testing the competing endogenous RNA (ceRNA hypothesis.

  12. Free energy minimization to predict RNA secondary structures and computational RNA design.

    Science.gov (United States)

    Churkin, Alexander; Weinbrand, Lina; Barash, Danny

    2015-01-01

    Determining the RNA secondary structure from sequence data by computational predictions is a long-standing problem. Its solution has been approached in two distinctive ways. If a multiple sequence alignment of a collection of homologous sequences is available, the comparative method uses phylogeny to determine conserved base pairs that are more likely to form as a result of billions of years of evolution than by chance. In the case of single sequences, recursive algorithms that compute free energy structures by using empirically derived energy parameters have been developed. This latter approach of RNA folding prediction by energy minimization is widely used to predict RNA secondary structure from sequence. For a significant number of RNA molecules, the secondary structure of the RNA molecule is indicative of its function and its computational prediction by minimizing its free energy is important for its functional analysis. A general method for free energy minimization to predict RNA secondary structures is dynamic programming, although other optimization methods have been developed as well along with empirically derived energy parameters. In this chapter, we introduce and illustrate by examples the approach of free energy minimization to predict RNA secondary structures.

  13. CompaRNA: a server for continuous benchmarking of automated methods for RNA secondary structure prediction

    Science.gov (United States)

    Puton, Tomasz; Kozlowski, Lukasz P.; Rother, Kristian M.; Bujnicki, Janusz M.

    2013-01-01

    We present a continuous benchmarking approach for the assessment of RNA secondary structure prediction methods implemented in the CompaRNA web server. As of 3 October 2012, the performance of 28 single-sequence and 13 comparative methods has been evaluated on RNA sequences/structures released weekly by the Protein Data Bank. We also provide a static benchmark generated on RNA 2D structures derived from the RNAstrand database. Benchmarks on both data sets offer insight into the relative performance of RNA secondary structure prediction methods on RNAs of different size and with respect to different types of structure. According to our tests, on the average, the most accurate predictions obtained by a comparative approach are generated by CentroidAlifold, MXScarna, RNAalifold and TurboFold. On the average, the most accurate predictions obtained by single-sequence analyses are generated by CentroidFold, ContextFold and IPknot. The best comparative methods typically outperform the best single-sequence methods if an alignment of homologous RNA sequences is available. This article presents the results of our benchmarks as of 3 October 2012, whereas the rankings presented online are continuously updated. We will gladly include new prediction methods and new measures of accuracy in the new editions of CompaRNA benchmarks. PMID:23435231

  14. A small RNA activates CFA synthase by isoform-specific mRNA stabilization.

    Science.gov (United States)

    Fröhlich, Kathrin Sophie; Papenfort, Kai; Fekete, Agnes; Vogel, Jörg

    2013-11-13

    Small RNAs use a diversity of well-characterized mechanisms to repress mRNAs, but how they activate gene expression at the mRNA level remains not well understood. The predominant activation mechanism of Hfq-associated small RNAs has been translational control whereby base pairing with the target prevents the formation of an intrinsic inhibitory structure in the mRNA and promotes translation initiation. Here, we report a translation-independent mechanism whereby the small RNA RydC selectively activates the longer of two isoforms of cfa mRNA (encoding cyclopropane fatty acid synthase) in Salmonella enterica. Target activation is achieved through seed pairing of the pseudoknot-exposed, conserved 5' end of RydC to an upstream region of the cfa mRNA. The seed pairing stabilizes the messenger, likely by interfering directly with RNase E-mediated decay in the 5' untranslated region. Intriguingly, this mechanism is generic such that the activation is equally achieved by seed pairing of unrelated small RNAs, suggesting that this mechanism may be utilized in the design of RNA-controlled synthetic circuits. Physiologically, RydC is the first small RNA known to regulate membrane stability.

  15. Analysis of hepatitis C virus RNA dimerization and core–RNA interactions

    Science.gov (United States)

    Ivanyi-Nagy, Roland; Kanevsky, Igor; Gabus, Caroline; Lavergne, Jean-Pierre; Ficheux, Damien; Penin, François; Fossé, Philippe; Darlix, Jean-Luc

    2006-01-01

    The core protein of hepatitis C virus (HCV) has been shown previously to act as a potent nucleic acid chaperone in vitro, promoting the dimerization of the 3′-untranslated region (3′-UTR) of the HCV genomic RNA, a process probably mediated by a small, highly conserved palindromic RNA motif, named DLS (dimer linkage sequence) [G. Cristofari, R. Ivanyi-Nagy, C. Gabus, S. Boulant, J. P. Lavergne, F. Penin and J. L. Darlix (2004) Nucleic Acids Res., 32, 2623–2631]. To investigate in depth HCV RNA dimerization, we generated a series of point mutations in the DLS region. We find that both the plus-strand 3′-UTR and the complementary minus-strand RNA can dimerize in the presence of core protein, while mutations in the DLS (among them a single point mutation that abolished RNA replication in a HCV subgenomic replicon system) completely abrogate dimerization. Structural probing of plus- and minus-strand RNAs, in their monomeric and dimeric forms, indicate that the DLS is the major if not the sole determinant of UTR RNA dimerization. Furthermore, the N-terminal basic amino acid clusters of core protein were found to be sufficient to induce dimerization, suggesting that they retain full RNA chaperone activity. These findings may have important consequences for understanding the HCV replicative cycle and the genetic variability of the virus. PMID:16707664

  16. Analysis of hepatitis C virus RNA dimerization and core-RNA interactions.

    Science.gov (United States)

    Ivanyi-Nagy, Roland; Kanevsky, Igor; Gabus, Caroline; Lavergne, Jean-Pierre; Ficheux, Damien; Penin, François; Fossé, Philippe; Darlix, Jean-Luc

    2006-01-01

    The core protein of hepatitis C virus (HCV) has been shown previously to act as a potent nucleic acid chaperone in vitro, promoting the dimerization of the 3'-untranslated region (3'-UTR) of the HCV genomic RNA, a process probably mediated by a small, highly conserved palindromic RNA motif, named DLS (dimer linkage sequence) [G. Cristofari, R. Ivanyi-Nagy, C. Gabus, S. Boulant, J. P. Lavergne, F. Penin and J. L. Darlix (2004) Nucleic Acids Res., 32, 2623-2631]. To investigate in depth HCV RNA dimerization, we generated a series of point mutations in the DLS region. We find that both the plus-strand 3'-UTR and the complementary minus-strand RNA can dimerize in the presence of core protein, while mutations in the DLS (among them a single point mutation that abolished RNA replication in a HCV subgenomic replicon system) completely abrogate dimerization. Structural probing of plus- and minus-strand RNAs, in their monomeric and dimeric forms, indicate that the DLS is the major if not the sole determinant of UTR RNA dimerization. Furthermore, the N-terminal basic amino acid clusters of core protein were found to be sufficient to induce dimerization, suggesting that they retain full RNA chaperone activity. These findings may have important consequences for understanding the HCV replicative cycle and the genetic variability of the virus.

  17. CompaRNA: a server for continuous benchmarking of automated methods for RNA secondary structure prediction.

    Science.gov (United States)

    Puton, Tomasz; Kozlowski, Lukasz P; Rother, Kristian M; Bujnicki, Janusz M

    2013-04-01

    We present a continuous benchmarking approach for the assessment of RNA secondary structure prediction methods implemented in the CompaRNA web server. As of 3 October 2012, the performance of 28 single-sequence and 13 comparative methods has been evaluated on RNA sequences/structures released weekly by the Protein Data Bank. We also provide a static benchmark generated on RNA 2D structures derived from the RNAstrand database. Benchmarks on both data sets offer insight into the relative performance of RNA secondary structure prediction methods on RNAs of different size and with respect to different types of structure. According to our tests, on the average, the most accurate predictions obtained by a comparative approach are generated by CentroidAlifold, MXScarna, RNAalifold and TurboFold. On the average, the most accurate predictions obtained by single-sequence analyses are generated by CentroidFold, ContextFold and IPknot. The best comparative methods typically outperform the best single-sequence methods if an alignment of homologous RNA sequences is available. This article presents the results of our benchmarks as of 3 October 2012, whereas the rankings presented online are continuously updated. We will gladly include new prediction methods and new measures of accuracy in the new editions of CompaRNA benchmarks.

  18. Visualizing double-stranded RNA distribution and dynamics in living cells by dsRNA binding-dependent fluorescence complementation

    International Nuclear Information System (INIS)

    Cheng, Xiaofei; Deng, Ping; Cui, Hongguang; Wang, Aiming

    2015-01-01

    Double-stranded RNA (dsRNA) is an important type of RNA that plays essential roles in diverse cellular processes in eukaryotic organisms and a hallmark in infections by positive-sense RNA viruses. Currently, no in vivo technology has been developed for visualizing dsRNA in living cells. Here, we report a dsRNA binding-dependent fluorescence complementation (dRBFC) assay that can be used to efficiently monitor dsRNA distribution and dynamics in vivo. The system consists of two dsRNA-binding proteins, which are fused to the N- and C-terminal halves of the yellow fluorescent protein (YFP). Binding of the two fusion proteins to a common dsRNA brings the split YFP halves in close proximity, leading to the reconstitution of the fluorescence-competent structure and restoration of fluorescence. Using this technique, we were able to visualize the distribution and trafficking of the replicative RNA intermediates of positive-sense RNA viruses in living cells. - Highlights: • A live-cell imaging system was developed for visualizing dsRNA in vivo. • It uses dsRNA binding proteins fused with two halves of a fluorescent protein. • Binding to a common dsRNA enables the reporter to become fluorescent. • The system can efficiently monitor viral RNA replication in living cells.

  19. Visualizing double-stranded RNA distribution and dynamics in living cells by dsRNA binding-dependent fluorescence complementation

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Xiaofei [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3 (Canada); College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 310036 (China); Deng, Ping; Cui, Hongguang [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3 (Canada); Wang, Aiming, E-mail: aiming.wang@agr.gc.ca [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3 (Canada)

    2015-11-15

    Double-stranded RNA (dsRNA) is an important type of RNA that plays essential roles in diverse cellular processes in eukaryotic organisms and a hallmark in infections by positive-sense RNA viruses. Currently, no in vivo technology has been developed for visualizing dsRNA in living cells. Here, we report a dsRNA binding-dependent fluorescence complementation (dRBFC) assay that can be used to efficiently monitor dsRNA distribution and dynamics in vivo. The system consists of two dsRNA-binding proteins, which are fused to the N- and C-terminal halves of the yellow fluorescent protein (YFP). Binding of the two fusion proteins to a common dsRNA brings the split YFP halves in close proximity, leading to the reconstitution of the fluorescence-competent structure and restoration of fluorescence. Using this technique, we were able to visualize the distribution and trafficking of the replicative RNA intermediates of positive-sense RNA viruses in living cells. - Highlights: • A live-cell imaging system was developed for visualizing dsRNA in vivo. • It uses dsRNA binding proteins fused with two halves of a fluorescent protein. • Binding to a common dsRNA enables the reporter to become fluorescent. • The system can efficiently monitor viral RNA replication in living cells.

  20. The microRNA and messengerRNA profile of the RNA-induced silencing complex in human primary astrocyte and astrocytoma cells.

    Science.gov (United States)

    Moser, Joanna J; Fritzler, Marvin J

    2010-10-18

    GW/P bodies are cytoplasmic ribonucleoprotein-rich foci involved in microRNA (miRNA)-mediated messenger RNA (mRNA) silencing and degradation. The mRNA regulatory functions within GW/P bodies are mediated by GW182 and its binding partner hAgo2 that bind miRNA in the RNA-induced silencing complex (RISC). To date there are no published reports of the profile of miRNA and mRNA targeted to the RISC or a comparison of the RISC-specific miRNA/mRNA profile differences in malignant and non-malignant cells. RISC mRNA and miRNA components were profiled by microarray analysis of malignant human U-87 astrocytoma cells and its non-malignant counterpart, primary human astrocytes. Total cell RNA as well as RNA from immunoprecipitated RISC was analyzed. The novel findings were fourfold: (1) miRNAs were highly enriched in astrocyte RISC compared to U-87 astrocytoma RISC, (2) astrocytoma and primary astrocyte cells each contained unique RISC miRNA profiles as compared to their respective cellular miRNA profiles, (3) miR-195, 10b, 29b, 19b, 34a and 455-3p levels were increased and the miR-181b level was decreased in U-87 astrocytoma RISC as compared to astrocyte RISC, and (4) the RISC contained decreased levels of mRNAs in primary astrocyte and U-87 astrocytoma cells. The observation that miR-34a and miR-195 levels were increased in the RISC of U-87 astrocytoma cells suggests an oncogenic role for these miRNAs. Differential regulation of mRNAs by specific miRNAs is evidenced by the observation that three miR34a-targeted mRNAs and two miR-195-targeted mRNAs were downregulated while one miR-195-targeted mRNA was upregulated. Biological pathway analysis of RISC mRNA components suggests that the RISC plays a pivotal role in malignancy and other conditions. This study points to the importance of the RISC and ultimately GW/P body composition and function in miRNA and mRNA deregulation in astrocytoma cells and possibly in other malignancies.

  1. The microRNA and messengerRNA profile of the RNA-induced silencing complex in human primary astrocyte and astrocytoma cells.

    Directory of Open Access Journals (Sweden)

    Joanna J Moser

    2010-10-01

    Full Text Available GW/P bodies are cytoplasmic ribonucleoprotein-rich foci involved in microRNA (miRNA-mediated messenger RNA (mRNA silencing and degradation. The mRNA regulatory functions within GW/P bodies are mediated by GW182 and its binding partner hAgo2 that bind miRNA in the RNA-induced silencing complex (RISC. To date there are no published reports of the profile of miRNA and mRNA targeted to the RISC or a comparison of the RISC-specific miRNA/mRNA profile differences in malignant and non-malignant cells.RISC mRNA and miRNA components were profiled by microarray analysis of malignant human U-87 astrocytoma cells and its non-malignant counterpart, primary human astrocytes. Total cell RNA as well as RNA from immunoprecipitated RISC was analyzed. The novel findings were fourfold: (1 miRNAs were highly enriched in astrocyte RISC compared to U-87 astrocytoma RISC, (2 astrocytoma and primary astrocyte cells each contained unique RISC miRNA profiles as compared to their respective cellular miRNA profiles, (3 miR-195, 10b, 29b, 19b, 34a and 455-3p levels were increased and the miR-181b level was decreased in U-87 astrocytoma RISC as compared to astrocyte RISC, and (4 the RISC contained decreased levels of mRNAs in primary astrocyte and U-87 astrocytoma cells.The observation that miR-34a and miR-195 levels were increased in the RISC of U-87 astrocytoma cells suggests an oncogenic role for these miRNAs. Differential regulation of mRNAs by specific miRNAs is evidenced by the observation that three miR34a-targeted mRNAs and two miR-195-targeted mRNAs were downregulated while one miR-195-targeted mRNA was upregulated. Biological pathway analysis of RISC mRNA components suggests that the RISC plays a pivotal role in malignancy and other conditions. This study points to the importance of the RISC and ultimately GW/P body composition and function in miRNA and mRNA deregulation in astrocytoma cells and possibly in other malignancies.

  2. tRNA-like structure regulates translation of Brome mosaic virus RNA.

    Science.gov (United States)

    Barends, Sharief; Rudinger-Thirion, Joëlle; Florentz, Catherine; Giegé, Richard; Pleij, Cornelis W A; Kraal, Barend

    2004-04-01

    For various groups of plant viruses, the genomic RNAs end with a tRNA-like structure (TLS) instead of the 3' poly(A) tail of common mRNAs. The actual function of these TLSs has long been enigmatic. Recently, however, it became clear that for turnip yellow mosaic virus, a tymovirus, the valylated TLS(TYMV) of the single genomic RNA functions as a bait for host ribosomes and directs them to the internal initiation site of translation (with N-terminal valine) of the second open reading frame for the polyprotein. This discovery prompted us to investigate whether the much larger TLSs of a different genus of viruses have a comparable function in translation. Brome mosaic virus (BMV), a bromovirus, has a tripartite RNA genome with a subgenomic RNA4 for coat protein expression. All four RNAs carry a highly conserved and bulky 3' TLS(BMV) (about 200 nucleotides) with determinants for tyrosylation. We discovered TLS(BMV)-catalyzed self-tyrosylation of the tyrosyl-tRNA synthetase but could not clearly detect tyrosine incorporation into any virus-encoded protein. We established that BMV proteins do not need TLS(BMV) tyrosylation for their initiation. However, disruption of the TLSs strongly reduced the translation of genomic RNA1, RNA2, and less strongly, RNA3, whereas coat protein expression from RNA4 remained unaffected. This aberrant translation could be partially restored by providing the TLS(BMV) in trans. Intriguingly, a subdomain of the TLS(BMV) could even almost fully restore translation to the original pattern. We discuss here a model with a central and dominant role for the TLS(BMV) during the BMV infection cycle.

  3. RNA-Seq of Bacillus licheniformis: active regulatory RNA features expressed within a productive fermentation

    Science.gov (United States)

    2013-01-01

    Background The production of enzymes by an industrial strain requires a complex adaption of the bacterial metabolism to the conditions within the fermenter. Regulatory events within the process result in a dynamic change of the transcriptional activity of the genome. This complex network of genes is orchestrated by proteins as well as regulatory RNA elements. Here we present an RNA-Seq based study considering selected phases of an industry-oriented fermentation of Bacillus licheniformis. Results A detailed analysis of 20 strand-specific RNA-Seq datasets revealed a multitude of transcriptionally active genomic regions. 3314 RNA features encoded by such active loci have been identified and sorted into ten functional classes. The identified sequences include the expected RNA features like housekeeping sRNAs, metabolic riboswitches and RNA switches well known from studies on Bacillus subtilis as well as a multitude of completely new candidates for regulatory RNAs. An unexpectedly high number of 855 RNA features are encoded antisense to annotated protein and RNA genes, in addition to 461 independently transcribed small RNAs. These antisense transcripts contain molecules with a remarkable size range variation from 38 to 6348 base pairs in length. The genome of the type strain B. licheniformis DSM13 was completely reannotated using data obtained from RNA-Seq analyses and from public databases. Conclusion The hereby generated data-sets represent a solid amount of knowledge on the dynamic transcriptional activities during the investigated fermentation stages. The identified regulatory elements enable research on the understanding and the optimization of crucial metabolic activities during a productive fermentation of Bacillus licheniformis strains. PMID:24079885

  4. RNA-Seq of Bacillus licheniformis: active regulatory RNA features expressed within a productive fermentation.

    Science.gov (United States)

    Wiegand, Sandra; Dietrich, Sascha; Hertel, Robert; Bongaerts, Johannes; Evers, Stefan; Volland, Sonja; Daniel, Rolf; Liesegang, Heiko

    2013-10-01

    The production of enzymes by an industrial strain requires a complex adaption of the bacterial metabolism to the conditions within the fermenter. Regulatory events within the process result in a dynamic change of the transcriptional activity of the genome. This complex network of genes is orchestrated by proteins as well as regulatory RNA elements. Here we present an RNA-Seq based study considering selected phases of an industry-oriented fermentation of Bacillus licheniformis. A detailed analysis of 20 strand-specific RNA-Seq datasets revealed a multitude of transcriptionally active genomic regions. 3314 RNA features encoded by such active loci have been identified and sorted into ten functional classes. The identified sequences include the expected RNA features like housekeeping sRNAs, metabolic riboswitches and RNA switches well known from studies on Bacillus subtilis as well as a multitude of completely new candidates for regulatory RNAs. An unexpectedly high number of 855 RNA features are encoded antisense to annotated protein and RNA genes, in addition to 461 independently transcribed small RNAs. These antisense transcripts contain molecules with a remarkable size range variation from 38 to 6348 base pairs in length. The genome of the type strain B. licheniformis DSM13 was completely reannotated using data obtained from RNA-Seq analyses and from public databases. The hereby generated data-sets represent a solid amount of knowledge on the dynamic transcriptional activities during the investigated fermentation stages. The identified regulatory elements enable research on the understanding and the optimization of crucial metabolic activities during a productive fermentation of Bacillus licheniformis strains.

  5. Short Hairpin RNA (shRNA): Design, Delivery, and Assessment of Gene Knockdown

    Science.gov (United States)

    Moore, Chris B.; Guthrie, Elizabeth H.; Huang, Max Tze-Han; Taxman, Debra J.

    2013-01-01

    Shortly after the cellular mechanism of RNA interference (RNAi) was first described, scientists began using this powerful technique to study gene function. This included designing better methods for the successful delivery of small interfering RNAs (siRNAs) and short hairpin RNAs (shRNAs) into mammalian cells. While the simplest method for RNAi is the cytosolic delivery of siRNA oligonucleotides, this technique is limited to cells capable of transfection and is primarily utilized during transient in vitro studies. The introduction of shRNA into mammalian cells through infection with viral vectors allows for stable integration of shRNA and long-term knockdown of the targeted gene; however, several challenges exist with the implementation of this technology. Here we describe some well-tested protocols which should increase the chances of successful design, delivery, and assessment of gene knockdown by shRNA. We provide suggestions for designing shRNA targets and controls, a protocol for sequencing through the secondary structure of the shRNA hairpin structure, and protocols for packaging and delivery of shRNA lentiviral particles. Using real-time PCR and functional assays we demonstrate the successful knockdown of ASC, an inflammatory adaptor molecule. These studies demonstrate the practicality of including two shRNAs with different efficacies of knockdown to provide an additional level of control and to verify dose dependency of functional effects. Along with the methods described here, as new techniques and algorithms are designed in the future, shRNA is likely to include further promising application and continue to be a critical component of gene discovery. PMID:20387148

  6. RNA inverse folding using Monte Carlo tree search.

    Science.gov (United States)

    Yang, Xiufeng; Yoshizoe, Kazuki; Taneda, Akito; Tsuda, Koji

    2017-11-06

    Artificially synthesized RNA molecules provide important ways for creating a variety of novel functional molecules. State-of-the-art RNA inverse folding algorithms can design simple and short RNA sequences of specific GC content, that fold into the target RNA structure. However, their performance is not satisfactory in complicated cases. We present a new inverse folding algorithm called MCTS-RNA, which uses Monte Carlo tree search (MCTS), a technique that has shown exceptional performance in Computer Go recently, to represent and discover the essential part of the sequence space. To obtain high accuracy, initial sequences generated by MCTS are further improved by a series of local updates. Our algorithm has an ability to control the GC content precisely and can deal with pseudoknot structures. Using common benchmark datasets for evaluation, MCTS-RNA showed a lot of promise as a standard method of RNA inverse folding. MCTS-RNA is available at https://github.com/tsudalab/MCTS-RNA .

  7. Rapid NMR screening of RNA secondary structure and binding

    International Nuclear Information System (INIS)

    Helmling, Christina; Keyhani, Sara; Sochor, Florian; Fürtig, Boris; Hengesbach, Martin; Schwalbe, Harald

    2015-01-01

    Determination of RNA secondary structures by NMR spectroscopy is a useful tool e.g. to elucidate RNA folding space or functional aspects of regulatory RNA elements. However, current approaches of RNA synthesis and preparation are usually time-consuming and do not provide analysis with single nucleotide precision when applied for a large number of different RNA sequences. Here, we significantly improve the yield and 3′ end homogeneity of RNA preparation by in vitro transcription. Further, by establishing a native purification procedure with increased throughput, we provide a shortcut to study several RNA constructs simultaneously. We show that this approach yields μmol quantities of RNA with purities comparable to PAGE purification, while avoiding denaturation of the RNA

  8. Drosha regulates gene expression independently of RNA cleavage function

    DEFF Research Database (Denmark)

    Gromak, Natalia; Dienstbier, Martin; Macias, Sara

    2013-01-01

    Drosha is the main RNase III-like enzyme involved in the process of microRNA (miRNA) biogenesis in the nucleus. Using whole-genome ChIP-on-chip analysis, we demonstrate that, in addition to miRNA sequences, Drosha specifically binds promoter-proximal regions of many human genes in a transcription......-dependent manner. This binding is not associated with miRNA production or RNA cleavage. Drosha knockdown in HeLa cells downregulated nascent gene transcription, resulting in a reduction of polyadenylated mRNA produced from these gene regions. Furthermore, we show that this function of Drosha is dependent on its N......-terminal protein-interaction domain, which associates with the RNA-binding protein CBP80 and RNA Polymerase II. Consequently, we uncover a previously unsuspected RNA cleavage-independent function of Drosha in the regulation of human gene expression....

  9. Rapid NMR screening of RNA secondary structure and binding

    Energy Technology Data Exchange (ETDEWEB)

    Helmling, Christina; Keyhani, Sara; Sochor, Florian; Fürtig, Boris; Hengesbach, Martin; Schwalbe, Harald, E-mail: schwalbe@nmr.uni-frankfurt.de [Johann Wolfgang Goethe-Universität, Institut für Organische Chemie und Chemische Biologie, Center for Biomolecular Magnetic Resonance (BMRZ) (Germany)

    2015-09-15

    Determination of RNA secondary structures by NMR spectroscopy is a useful tool e.g. to elucidate RNA folding space or functional aspects of regulatory RNA elements. However, current approaches of RNA synthesis and preparation are usually time-consuming and do not provide analysis with single nucleotide precision when applied for a large number of different RNA sequences. Here, we significantly improve the yield and 3′ end homogeneity of RNA preparation by in vitro transcription. Further, by establishing a native purification procedure with increased throughput, we provide a shortcut to study several RNA constructs simultaneously. We show that this approach yields μmol quantities of RNA with purities comparable to PAGE purification, while avoiding denaturation of the RNA.

  10. Short RNA guides cleavage by eukaryotic RNase III.

    Directory of Open Access Journals (Sweden)

    Bruno Lamontagne

    Full Text Available In eukaryotes, short RNAs guide a variety of enzymatic activities that range from RNA editing to translation repression. It is hypothesized that pre-existing proteins evolved to bind and use guide RNA during evolution. However, the capacity of modern proteins to adopt new RNA guides has never been demonstrated. Here we show that Rnt1p, the yeast orthologue of the bacterial dsRNA-specific RNase III, can bind short RNA transcripts and use them as guides for sequence-specific cleavage. Target cleavage occurred at a constant distance from the Rnt1p binding site, leaving the guide RNA intact for subsequent cleavage. Our results indicate that RNase III may trigger sequence-specific RNA degradation independent of the RNAi machinery, and they open the road for a new generation of precise RNA silencing tools that do not trigger a dsRNA-mediated immune response.

  11. RNA Editing and Drug Discovery for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Wei-Hsuan Huang

    2013-01-01

    Full Text Available RNA editing is vital to provide the RNA and protein complexity to regulate the gene expression. Correct RNA editing maintains the cell function and organism development. Imbalance of the RNA editing machinery may lead to diseases and cancers. Recently, RNA editing has been recognized as a target for drug discovery although few studies targeting RNA editing for disease and cancer therapy were reported in the field of natural products. Therefore, RNA editing may be a potential target for therapeutic natural products. In this review, we provide a literature overview of the biological functions of RNA editing on gene expression, diseases, cancers, and drugs. The bioinformatics resources of RNA editing were also summarized.

  12. Circular RNA and miR-7 in Cancer

    DEFF Research Database (Denmark)

    Hansen, Thomas Birkballe; Kjems, Jørgen; Damgaard, Christian Kroun

    2013-01-01

    MicroRNAs (miRNA) play important roles in fine-tuning gene expression and are often deregulated in cancer. The identification of competing endogenous RNA and circular RNA (circRNA) as important regulators of miRNA activity underscores the increasing complexity of ncRNA-mediated regulatory networks....... Particularly, the recently identified circular RNA, ciRS-7, which acts as a designated miR-7 inhibitor/sponge, has conceptually changed the mechanistic understanding of miRNA networks. As miR-7 modulates the expression of several oncogenes, disclosing the regulation of miR-7 activity will likely advance...... the understanding of various cancer etiologies. Here, we review the current knowledge about the ciRS-7/miR-7 axis in cancer-related pathways and discuss possible models explaining the relevance of coexpressing miR-7 along with a circRNA inhibitor....

  13. Guardian of Genetic Messenger-RNA-Binding Proteins

    Directory of Open Access Journals (Sweden)

    Antje Anji

    2016-01-01

    Full Text Available RNA in cells is always associated with RNA-binding proteins that regulate all aspects of RNA metabolism including RNA splicing, export from the nucleus, RNA localization, mRNA turn-over as well as translation. Given their diverse functions, cells express a variety of RNA-binding proteins, which play important roles in the pathologies of a number of diseases. In this review we focus on the effect of alcohol on different RNA-binding proteins and their possible contribution to alcohol-related disorders, and discuss the role of these proteins in the development of neurological diseases and cancer. We further discuss the conventional methods and newer techniques that are employed to identify RNA-binding proteins.

  14. Automated identification of RNA 3D modules with discriminative power in RNA structural alignments

    DEFF Research Database (Denmark)

    Theis, Corinna; Höner zu Siederdissen, Christian; Hofacker, Ivo L.

    2013-01-01

    Recent progress in predicting RNA structure is moving towards filling the 'gap' in 2D RNA structure prediction where, for example, predicted internal loops often form non-canonical base pairs. This is increasingly recognized with the steady increase of known RNA 3D modules. There is a general...... comparative evidence. Subsequently, the modules, initially represented by a graph, are turned into models for the RMDetect program, which allows to test their discriminative power using real and randomized Rfam alignments. An initial extraction of 22495 3D modules in all PDB files results in 977 internal loop...

  15. RNA-Pareto: interactive analysis of Pareto-optimal RNA sequence-structure alignments.

    Science.gov (United States)

    Schnattinger, Thomas; Schöning, Uwe; Marchfelder, Anita; Kestler, Hans A

    2013-12-01

    Incorporating secondary structure information into the alignment process improves the quality of RNA sequence alignments. Instead of using fixed weighting parameters, sequence and structure components can be treated as different objectives and optimized simultaneously. The result is not a single, but a Pareto-set of equally optimal solutions, which all represent different possible weighting parameters. We now provide the interactive graphical software tool RNA-Pareto, which allows a direct inspection of all feasible results to the pairwise RNA sequence-structure alignment problem and greatly facilitates the exploration of the optimal solution set.

  16. Regulatory effects of cotranscriptional RNA structure formation and transitions.

    Science.gov (United States)

    Liu, Sheng-Rui; Hu, Chun-Gen; Zhang, Jin-Zhi

    2016-09-01

    RNAs, which play significant roles in many fundamental biological processes of life, fold into sophisticated and precise structures. RNA folding is a dynamic and intricate process, which conformation transition of coding and noncoding RNAs form the primary elements of genetic regulation. The cellular environment contains various intrinsic and extrinsic factors that potentially affect RNA folding in vivo, and experimental and theoretical evidence increasingly indicates that the highly flexible features of the RNA structure are affected by these factors, which include the flanking sequence context, physiochemical conditions, cis RNA-RNA interactions, and RNA interactions with other molecules. Furthermore, distinct RNA structures have been identified that govern almost all steps of biological processes in cells, including transcriptional activation and termination, transcriptional mutagenesis, 5'-capping, splicing, 3'-polyadenylation, mRNA export and localization, and translation. Here, we briefly summarize the dynamic and complex features of RNA folding along with a wide variety of intrinsic and extrinsic factors that affect RNA folding. We then provide several examples to elaborate RNA structure-mediated regulation at the transcriptional and posttranscriptional levels. Finally, we illustrate the regulatory roles of RNA structure and discuss advances pertaining to RNA structure in plants. WIREs RNA 2016, 7:562-574. doi: 10.1002/wrna.1350 For further resources related to this article, please visit the WIREs website. © 2016 Wiley Periodicals, Inc.

  17. RNA Polymerase II–The Transcription Machine

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 3. RNA Polymerase II – The Transcription Machine - Nobel Prize in Chemistry 2006. Jiyoti Verma Aruna Naorem Anand Kumar Manimala Sen Parag Sadhale. General Article Volume 12 Issue 3 March 2007 pp 47-53 ...

  18. RNA interference: its use as antiviral therapy

    NARCIS (Netherlands)

    Haasnoot, J.; Berkhout, B.

    2006-01-01

    RNA interference (RNAi) is a sequence-specific gene-silencing mechanism that has been proposed to function as a defence mechanism of eukaryotic cells against viruses and transposons. RNAi was first observed in plants in the form of a mysterious immune response to viral pathogens. But RNAi is more

  19. DNA and RNA Quadruplex-Binding Proteins

    Czech Academy of Sciences Publication Activity Database

    Brázda, Václav; Haroniková, Lucia; Liao, J.C.C.; Fojta, Miroslav

    2014-01-01

    Roč. 15, č. 10 (2014), s. 17493-17517 E-ISSN 1422-0067 R&D Projects: GA ČR(CZ) GBP206/12/G151 Institutional support: RVO:68081707 Keywords : DNA quadruplex * RNA quadruplex * telomere Subject RIV: BO - Biophysics Impact factor: 2.862, year: 2014

  20. MicroRNA biomarkers in glioblastoma

    DEFF Research Database (Denmark)

    Hermansen, Simon Kjær; Kristensen, Bjarne Winther

    2013-01-01

    tissues. Understanding these alterations is key to developing new biomarkers and intelligent treatment strategies. This review presents an overview of current knowledge about miRNA alterations in glioblastoma while focusing on the clinical future of miRNAs as biomarkers and discussing the strengths...

  1. Symmetric Circular Matchings and RNA Folding

    DEFF Research Database (Denmark)

    Hofacker, Ivo L.; Reidys, Christian; Stadler, Peter F.

    2012-01-01

    RNA secondary structures can be computed as optimal solutions of certain circular matching problems. An accurate treatment of this energy minimization problem has to account for the small --- but non-negligible --- entropic destabilization of secondary structures with non-trivial automorphisms. S...

  2. siRNA for Influenza Therapy

    Directory of Open Access Journals (Sweden)

    Sailen Barik

    2010-07-01

    Full Text Available Influenza virus is one of the most prevalent and ancient infections in humans. About a fifth of world's population is infected by influenza virus annually, leading to high morbidity and mortality, particularly in infants, the elderly and the immunocompromised. In the US alone, influenza outbreaks lead to roughly 30,000 deaths each year. Current vaccines and anti-influenza drugs are of limited use due to high mutation rate of the virus and side effects. In recent years, RNA interference, triggered by synthetic short interfering RNA (siRNA, has rapidly evolved as a potent antiviral regimen. Properly designed siRNAs have been shown to function as potent inhibitors of influenza virus replication. The siRNAs outperform traditional small molecule antivirals in a number of areas, such as ease of design, modest cost, and fast turnaround. Although specificity and tissue delivery remain major bottlenecks in the clinical applications of RNAi in general, intranasal application of siRNA against respiratory viruses including, but not limited to influenza virus, has experienced significant success and optimism, which is reviewed here.

  3. siRNA for Influenza Therapy.

    Science.gov (United States)

    Barik, Sailen

    2010-07-01

    Influenza virus is one of the most prevalent and ancient infections in humans. About a fifth of world's population is infected by influenza virus annually, leading to high morbidity and mortality, particularly in infants, the elderly and the immunocompromised. In the US alone, influenza outbreaks lead to roughly 30,000 deaths each year. Current vaccines and anti-influenza drugs are of limited use due to high mutation rate of the virus and side effects. In recent years, RNA interference, triggered by synthetic short interfering RNA (siRNA), has rapidly evolved as a potent antiviral regimen. Properly designed siRNAs have been shown to function as potent inhibitors of influenza virus replication. The siRNAs outperform traditional small molecule antivirals in a number of areas, such as ease of design, modest cost, and fast turnaround. Although specificity and tissue delivery remain major bottlenecks in the clinical applications of RNAi in general, intranasal application of siRNA against respiratory viruses including, but not limited to influenza virus, has experienced significant success and optimism, which is reviewed here.

  4. Inhibition of virus replication by RNA interference

    NARCIS (Netherlands)

    Haasnoot, P. C. Joost; Cupac, Daniel; Berkhout, Ben

    2003-01-01

    RNA interference (RNAi) is a sequence-specific gene-silencing mechanism in eukaryotes, which is believed to function as a defence against viruses and transposons. Since its discovery, RNAi has been developed into a widely used technique for generating genetic knock-outs and for studying gene

  5. Spliced RNA of woodchuck hepatitis virus.

    Science.gov (United States)

    Ogston, C W; Razman, D G

    1992-07-01

    Polymerase chain reaction was used to investigate RNA splicing in liver of woodchucks infected with woodchuck hepatitis virus (WHV). Two spliced species were detected, and the splice junctions were sequenced. The larger spliced RNA has an intron of 1300 nucleotides, and the smaller spliced sequence shows an additional downstream intron of 1104 nucleotides. We did not detect singly spliced sequences from which the smaller intron alone was removed. Control experiments showed that spliced sequences are present in both RNA and DNA in infected liver, showing that the viral reverse transcriptase can use spliced RNA as template. Spliced sequences were detected also in virion DNA prepared from serum. The upstream intron produces a reading frame that fuses the core to the polymerase polypeptide, while the downstream intron causes an inframe deletion in the polymerase open reading frame. Whereas the splicing patterns in WHV are superficially similar to those reported recently in hepatitis B virus, we detected no obvious homology in the coding capacity of spliced RNAs from these two viruses.

  6. CBC bound proteins and RNA fate

    DEFF Research Database (Denmark)

    Giacometti, Simone

    ) complex (CBCN), were recently shown to target capped RNA either toward export or degradation, but the mechanisms by which they can discriminate between different RNA families and route them toward different metabolic pathways still remain unclear. A major question to be answered is how and when...... the different CBC subcomplexes are recruited to the RNP. Here, we used an individual nucleotide-resolution UV cross-linking and immunoprecipitation (iCLIP) approach to identify the transcriptome-wide targets for 5 different components of the CBCAP and CBCN complexes, and compared results to the previously...... analysed NEXT-component RBM7. We report that: (i) CBP20, ARS2, PHAX and ZC3H18 bind close to the cap, while RBM7 and MTR4 bind throughout the mRNA body; (ii) CBP20, ARS2, PHAX and ZC3H18 associate with a broad set of RNA polymerase II (PolII)-derived RNAs and have only mild species preferences; (iii...

  7. RNA polymerase II collision interrupts convergent transcription

    DEFF Research Database (Denmark)

    Hobson, David J; Wei, Wu; Steinmetz, Lars M

    2012-01-01

    Antisense noncoding transcripts, genes-within-genes, and convergent gene pairs are prevalent among eukaryotes. The existence of such transcription units raises the question of what happens when RNA polymerase II (RNAPII) molecules collide head-to-head. Here we use a combination of biochemical...

  8. Mapping the universe of RNA tetraloop folds

    DEFF Research Database (Denmark)

    Bottaro, Sandro; Lindorff-Larsen, Kresten

    2017-01-01

    We report a map of RNA tetraloop conformations constructed by calculating pairwise distances among all experimentally determined four-nucleotide hairpin loops. Tetraloops with similar structures are clustered together and, as expected, the two largest clusters are the canonical GNRA and UNCG fold...

  9. Molecular dynamics simulations of RNA motifs

    Czech Academy of Sciences Publication Activity Database

    Csaszar, K.; Špačková, Naďa; Šponer, Jiří; Leontis, N. B.

    2002-01-01

    Roč. 223, - (2002), s. 154 ISSN 0065-7727. [Annual Meeting of the American Chemistry Society /223./. 07.04.2002-11.04.2002, Orlando ] Institutional research plan: CEZ:AV0Z5004920 Keywords : molecular dynamics * RNA * hydration Subject RIV: BO - Biophysics

  10. Priit Pärna joonisfilmid / Grete Nootre

    Index Scriptorium Estoniae

    Nootre, Grete

    2005-01-01

    Eesti Joonisfilm laskis välja neli videokassetti eesti joonisfilmidega : kaks Priit Pärna viimaste töödega ning kaks tema noorte kolleegide Priit Tenderi, Kaspar Jancise ja Ülo Pikkovi loominguga. Toodud ära ka kirjastuse "Tachen" käsiraamatu "Animation Now!" hinnang Priit Pärnale

  11. Functional RNA during Zika virus infection

    NARCIS (Netherlands)

    Göertz, Giel P.; Abbo, Sandra R.; Fros, Jelke J.; Pijlman, Gorben P.

    2017-01-01

    Zika virus (ZIKV; family Flaviviridae; genus Flavivirus) is a pathogenic mosquito-borne RNA virus that currently threatens human health in the Americas, large parts of Asia and occasionally elsewhere in the world. ZIKV infection is often asymptomatic but can cause severe symptoms including

  12. A toolbox for miRNA analysis

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Petr

    2015-01-01

    Roč. 589, č. 14 (2015), s. 1694-1701 ISSN 0014-5793 R&D Projects: GA MŠk LO1419 Institutional support: RVO:68378050 Keywords : MicroRNA * Antagomir * Inhibition * Reporter * Locked nucleic acids Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.519, year: 2015

  13. RNA-dependent RNA polymerase 1 in potato (Solanum tuberosum) and its relationship to other plant RNA-dependent RNA polymerases.

    Science.gov (United States)

    Hunter, Lydia J R; Brockington, Samuel F; Murphy, Alex M; Pate, Adrienne E; Gruden, Kristina; MacFarlane, Stuart A; Palukaitis, Peter; Carr, John P

    2016-03-16

    Cellular RNA-dependent RNA polymerases (RDRs) catalyze synthesis of double-stranded RNAs that can serve to initiate or amplify RNA silencing. Arabidopsis thaliana has six RDR genes; RDRs 1, 2 and 6 have roles in anti-viral RNA silencing. RDR6 is constitutively expressed but RDR1 expression is elevated following plant treatment with defensive phytohormones. RDR1 also contributes to basal virus resistance. RDR1 has been studied in several species including A. thaliana, tobacco (Nicotiana tabacum), N. benthamiana, N. attenuata and tomato (Solanum lycopersicum) but not to our knowledge in potato (S. tuberosum). StRDR1 was identified and shown to be salicylic acid-responsive. StRDR1 transcript accumulation decreased in transgenic potato plants constitutively expressing a hairpin construct and these plants were challenged with three viruses: potato virus Y, potato virus X, and tobacco mosaic virus. Suppression of StRDR1 gene expression did not increase the susceptibility of potato to these viruses. Phylogenetic analysis of RDR genes present in potato and in a range of other plant species identified a new RDR gene family, not present in potato and found only in Rosids (but apparently lost in the Rosid A. thaliana) for which we propose the name RDR7.

  14. RCrane: semi-automated RNA model building

    International Nuclear Information System (INIS)

    Keating, Kevin S.; Pyle, Anna Marie

    2012-01-01

    RCrane is a new tool for the partially automated building of RNA crystallographic models into electron-density maps of low or intermediate resolution. This tool helps crystallographers to place phosphates and bases into electron density and then automatically predicts and builds the detailed all-atom structure of the traced nucleotides. RNA crystals typically diffract to much lower resolutions than protein crystals. This low-resolution diffraction results in unclear density maps, which cause considerable difficulties during the model-building process. These difficulties are exacerbated by the lack of computational tools for RNA modeling. Here, RCrane, a tool for the partially automated building of RNA into electron-density maps of low or intermediate resolution, is presented. This tool works within Coot, a common program for macromolecular model building. RCrane helps crystallographers to place phosphates and bases into electron density and then automatically predicts and builds the detailed all-atom structure of the traced nucleotides. RCrane then allows the crystallographer to review the newly built structure and select alternative backbone conformations where desired. This tool can also be used to automatically correct the backbone structure of previously built nucleotides. These automated corrections can fix incorrect sugar puckers, steric clashes and other structural problems

  15. Visualization of enhancer-derived noncoding RNA

    CSIR Research Space (South Africa)

    Shibayama, Y

    2017-01-01

    Full Text Available component of enhancer function, their expression has not been broadly analyzed at a single cell level via imaging techniques. This protocol describes a method to image eRNA in single cells by in situ hybridization followed by tyramide signal amplifi cation...

  16. RNA assemblages orchestrate complex cellular processes

    DEFF Research Database (Denmark)

    Nielsen, Finn Cilius; Hansen, Heidi Theil; Christiansen, Jan

    2016-01-01

    Eukaryotic mRNAs are monocistronic, and therefore mechanisms exist that coordinate the synthesis of multiprotein complexes in order to obtain proper stoichiometry at the appropriate intracellular locations. RNA-binding proteins containing low-complexity sequences are prone to generate liquid drop...

  17. MicroRNA profiling in intraocular medulloepitheliomas.

    Directory of Open Access Journals (Sweden)

    Deepak P Edward

    Full Text Available To study the differential expression of microRNA (miRNA profiles between intraocular medulloepithelioma (ME and normal control tissue (CT.Total RNA was extracted from formalin fixed paraffin embedded (FFPE intraocular ME (n=7 and from age matched ciliary body controls (n=8. The clinical history and phenotype was recorded. MiRNA profiles were determined using the Affymetrix GeneChip miRNA Arrays analyzed using expression console 1.3 software. Validation of significantly dysregulated miRNA was confirmed by quantitative real-time PCR. The web-based DNA Intelligent Analysis (DIANA-miRPath v2.0 was used to perform enrichment analysis of differentially expressed (DE miRNA gene targets in Kyoto Encyclopedia of Genes and Genomes (KEGG pathway.The pathologic evaluation revealed one benign (benign non-teratoid, n=1 and six malignant tumors (malignant teratoid, n=2; malignant non-teratoid, n = 4. A total of 88 miRNAs were upregulated and 43 miRNAs were downregulated significantly (P<0.05 in the tumor specimens. Many of these significantly dysregulated miRNAs were known to play various roles in carcinogenesis and tumor behavior. RT-PCR validated three significantly upregulated miRNAs and three significantly downregulated miRNAs namely miR-217, miR-216a, miR-216b, miR-146a, miR-509-3p and miR-211. Many DE miRNAs that were significant in ME tumors showed dysregulation in retinoblastoma, glioblastoma, and precursor, normal and reactive human cartilage. Enriched pathway analysis suggested a significant association of upregulated miRNAs with 15 pathways involved in prion disease and several types of cancer. The pathways involving significantly downregulated miRNAs included the toll-like receptor (TLR (p<4.36E-16 and Nuclear Factor kappa B (NF-κB signaling pathways (p<9.00E-06.We report significantly dysregulated miRNAs in intraocular ME tumors, which exhibited abnormal profiles in other cancers as well such as retinoblastoma and glioblastoma. Pathway analysis

  18. The snakelike chain character of unstructured RNA.

    Science.gov (United States)

    Jacobson, David R; McIntosh, Dustin B; Saleh, Omar A

    2013-12-03

    In the absence of base-pairing and tertiary structure, ribonucleic acid (RNA) assumes a random-walk conformation, modulated by the electrostatic self-repulsion of the charged, flexible backbone. This behavior is often modeled as a Kratky-Porod "wormlike chain" (WLC) with a Barrat-Joanny scale-dependent persistence length. In this study we report measurements of the end-to-end extension of poly(U) RNA under 0.1 to 10 pN applied force and observe two distinct elastic-response regimes: a low-force, power-law regime characteristic of a chain of swollen blobs on long length scales and a high-force, salt-valence-dependent regime consistent with ion-stabilized crumpling on short length scales. This short-scale structure is additionally supported by force- and salt-dependent quantification of the RNA ion atmosphere composition, which shows that ions are liberated under stretching; the number of ions liberated increases with increasing bulk salt concentration. Both this result and the observation of two elastic-response regimes directly contradict the WLC model, which predicts a single elastic regime across all forces and, when accounting for scale-dependent persistence length, the opposite trend in ion release with salt concentration. We conclude that RNA is better described as a "snakelike chain," characterized by smooth bending on long length scales and ion-stabilized crumpling on short length scales. In monovalent salt, these two regimes are separated by a characteristic length that scales with the Debye screening length, highlighting the determining importance of electrostatics in RNA conformation. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  19. Processivity and coupling in messenger RNA transcription.

    Directory of Open Access Journals (Sweden)

    Stuart Aitken

    2010-01-01

    Full Text Available The complexity of messenger RNA processing is now being uncovered by experimental techniques that are capable of detecting individual copies of mRNA in cells, and by quantitative real-time observations that reveal the kinetics. This processing is commonly modelled by permitting mRNA to be transcribed only when the promoter is in the on state. In this simple on/off model, the many processes involved in active transcription are represented by a single reaction. These processes include elongation, which has a minimum time for completion and processing that is not captured in the model.In this paper, we explore the impact on the mRNA distribution of representing the elongation process in more detail. Consideration of the mechanisms of elongation leads to two alternative models of the coupling between the elongating polymerase and the state of the promoter: Processivity allows polymerases to complete elongation irrespective of the promoter state, whereas coupling requires the promoter to be active to produce a full-length transcript. We demonstrate that these alternatives have a significant impact on the predicted distributions. Models are simulated by the Gillespie algorithm, and the third and fourth moments of the resulting distribution are computed in order to characterise the length of the tail, and sharpness of the peak. By this methodology, we show that the moments provide a concise summary of the distribution, showing statistically-significant differences across much of the feasible parameter range.We conclude that processivity is not fully consistent with the on/off model unless the probability of successfully completing elongation is low--as has been observed. The results also suggest that some form of coupling between the promoter and a rate-limiting step in transcription may explain the cell's inability to maintain high mRNA levels at low noise--a prediction of the on/off model that has no supporting evidence.

  20. siRNA delivery with lipid-based systems

    DEFF Research Database (Denmark)

    Foged, Camilla

    2012-01-01

    A key hurdle for the further development of RNA interference (RNAi) therapeutics like small interfering RNA (siRNA) is their safe and effective delivery. Lipids are promising and versatile carriers because they are based on Nature's own building blocks and can be provided with properties which......RNA into more hydrophobic lipoplexes, which promote passage of the siRNA across cellular membrane barriers, especially when lipids are added that facilitate membrane fusion. Despite these attractive features, siRNA delivery vehicles are facing a number of challenges such as the limited delivery efficiency...

  1. Evaluation of two main RNA-seq approaches for gene quantification in clinical RNA sequencing: polyA+ selection versus rRNA depletion.

    Science.gov (United States)

    Zhao, Shanrong; Zhang, Ying; Gamini, Ramya; Zhang, Baohong; von Schack, David

    2018-03-19

    To allow efficient transcript/gene detection, highly abundant ribosomal RNAs (rRNA) are generally removed from total RNA either by positive polyA+ selection or by rRNA depletion (negative selection) before sequencing. Comparisons between the two methods have been carried out by various groups, but the assessments have relied largely on non-clinical samples. In this study, we evaluated these two RNA sequencing approaches using human blood and colon tissue samples. Our analyses showed that rRNA depletion captured more unique transcriptome features, whereas polyA+ selection outperformed rRNA depletion with higher exonic coverage and better accuracy of gene quantification. For blood- and colon-derived RNAs, we found that 220% and 50% more reads, respectively, would have to be sequenced to achieve the same level of exonic coverage in the rRNA depletion method compared with the polyA+ selection method. Therefore, in most cases we strongly recommend polyA+ selection over rRNA depletion for gene quantification in clinical RNA sequencing. Our evaluation revealed that a small number of lncRNAs and small RNAs made up a large fraction of the reads in the rRNA depletion RNA sequencing data. Thus, we recommend that these RNAs are specifically depleted to improve the sequencing depth of the remaining RNAs.

  2. Comparison of methods for miRNA extraction from plasma and quantitative recovery of RNA from plasma and cerebrospinal fluid

    Directory of Open Access Journals (Sweden)

    Melissa A McAlexander

    2013-05-01

    Full Text Available Interest in extracellular RNA has intensified as evidence accumulates that these molecules may be useful as indicators of a wide variety of biological conditions. To establish specific extracellular RNA molecules as clinically relevant biomarkers, reproducible recovery from biological samples and reliable measurements of the isolated RNA are paramount. Towards these ends, careful and rigorous comparisons of technical procedures are needed at all steps from sample handling to RNA isolation to RNA measurement protocols. In the investigations described in this methods paper, RT-qPCR was used to examine the apparent recovery of specific endogenous miRNAs and a spiked-in synthetic RNA from blood plasma samples. RNA was isolated using several widely used RNA isolation kits, with or without the addition of glycogen as a carrier. Kits examined included total RNA isolation systems that have been commercially available for several years and commonly adapted for extraction of biofluid RNA, as well as more recently introduced biofluids-specific RNA methods. Our conclusions include the following: some RNA isolation methods appear to be superior to others for the recovery of RNA from biological fluids; addition of a carrier molecule seems to be beneficial for some but not all isolation methods; and partially or fully quantitative recovery of RNA is observed from increasing volumes of plasma and cerebrospinal fluid.

  3. Improved crystallization of the coxsackievirus B3 RNA-dependent RNA polymerase

    Energy Technology Data Exchange (ETDEWEB)

    Jabafi, Ilham; Selisko, Barbara; Coutard, Bruno; De Palma, Armando M.; Neyts, Johan; Egloff, Marie-Pierre; Grisel, Sacha; Dalle, Karen; Campanacci, Valerie; Spinelli, Silvia; Cambillau, Christian; Canard, Bruno; Gruez, Arnaud, E-mail: arnaud.gruez@maem.uhp-nancy.fr [Centre National de la Recherche Scientifique and Universités d’Aix-Marseille I et II, UMR 6098, Architecture et Fonction des Macromolécules Biologiques, Ecole Supérieure d’Ingénieurs de Luminy-Case 925, 163 Avenue de Luminy, 13288 Marseille CEDEX 9 (France)

    2007-06-01

    The first crystal of a coxsackievirus RNA-dependent RNA polymerase is reported. The Picornaviridae virus family contains a large number of human pathogens such as poliovirus, hepatitis A virus and rhinoviruses. Amongst the viruses belonging to the genus Enterovirus, several serotypes of coxsackievirus coexist for which neither vaccine nor therapy is available. Coxsackievirus B3 is involved in the development of acute myocarditis and dilated cardiomyopathy and is thought to be an important cause of sudden death in young adults. Here, the first crystal of a coxsackievirus RNA-dependent RNA polymerase is reported. Standard crystallization methods yielded crystals that were poorly suited to X-ray diffraction studies, with one axis being completely disordered. Crystallization was improved by testing crystallization solutions from commercial screens as additives. This approach yielded crystals that diffracted to 2.1 Å resolution and that were suitable for structure determination.

  4. Improved crystallization of the coxsackievirus B3 RNA-dependent RNA polymerase

    International Nuclear Information System (INIS)

    Jabafi, Ilham; Selisko, Barbara; Coutard, Bruno; De Palma, Armando M.; Neyts, Johan; Egloff, Marie-Pierre; Grisel, Sacha; Dalle, Karen; Campanacci, Valerie; Spinelli, Silvia; Cambillau, Christian; Canard, Bruno; Gruez, Arnaud

    2007-01-01

    The first crystal of a coxsackievirus RNA-dependent RNA polymerase is reported. The Picornaviridae virus family contains a large number of human pathogens such as poliovirus, hepatitis A virus and rhinoviruses. Amongst the viruses belonging to the genus Enterovirus, several serotypes of coxsackievirus coexist for which neither vaccine nor therapy is available. Coxsackievirus B3 is involved in the development of acute myocarditis and dilated cardiomyopathy and is thought to be an important cause of sudden death in young adults. Here, the first crystal of a coxsackievirus RNA-dependent RNA polymerase is reported. Standard crystallization methods yielded crystals that were poorly suited to X-ray diffraction studies, with one axis being completely disordered. Crystallization was improved by testing crystallization solutions from commercial screens as additives. This approach yielded crystals that diffracted to 2.1 Å resolution and that were suitable for structure determination

  5. Chitosan/siRNA nanoparticles encapsulated in PLGA nanofibers for siRNA delivery

    DEFF Research Database (Denmark)

    Chen, Menglin; Gao, Shan; Dong, Mingdong

    2012-01-01

    Composite nanofibers of biodegradable poly(d,l-lactic-co-glycolic acid) (PLGA) encapsulating chitosan/siRNA nanoparticles (NPs) were prepared by electrospinning. Acidic/alkaline hydrolysis and a bulk/surface degradation mechanism were investigated in order to achieve an optimized release profile...... for prolonged and efficient gene silencing. Thermo-controlled AFM in situ imaging not only revealed the integrity of the encapsulated chitosan/siRNA polyplex but also shed light on the decreasing Tg of PLGA on the fiber surfaces during release. A triphasic release profile based on bulk erosion was obtained at p......RNA transfection, where the encapsulated chitosan/siRNA NPs exhibited up to 50% EGFP gene silencing activity after 48 h post-transfection on H1299 cells....

  6. Structure of an RNA dimer of a regulatory element from human thymidylate synthase mRNA

    OpenAIRE

    Dibrov, Sergey; McLean, Jaime; Hermann, Thomas

    2011-01-01

    An oligonucleotide representing a regulatory element of human thymidylate synthase mRNA has been crystallized as a dimer. The structure of the asymmetric dimer has been determined at 1.97 Å resolution.

  7. A path-based measurement for human miRNA functional similarities using miRNA-disease associations

    Science.gov (United States)

    Ding, Pingjian; Luo, Jiawei; Xiao, Qiu; Chen, Xiangtao

    2016-09-01

    Compared with the sequence and expression similarity, miRNA functional similarity is so important for biology researches and many applications such as miRNA clustering, miRNA function prediction, miRNA synergism identification and disease miRNA prioritization. However, the existing methods always utilized the predicted miRNA target which has high false positive and false negative to calculate the miRNA functional similarity. Meanwhile, it is difficult to achieve high reliability of miRNA functional similarity with miRNA-disease associations. Therefore, it is increasingly needed to improve the measurement of miRNA functional similarity. In this study, we develop a novel path-based calculation method of miRNA functional similarity based on miRNA-disease associations, called MFSP. Compared with other methods, our method obtains higher average functional similarity of intra-family and intra-cluster selected groups. Meanwhile, the lower average functional similarity of inter-family and inter-cluster miRNA pair is obtained. In addition, the smaller p-value is achieved, while applying Wilcoxon rank-sum test and Kruskal-Wallis test to different miRNA groups. The relationship between miRNA functional similarity and other information sources is exhibited. Furthermore, the constructed miRNA functional network based on MFSP is a scale-free and small-world network. Moreover, the higher AUC for miRNA-disease prediction indicates the ability of MFSP uncovering miRNA functional similarity.

  8. Chimira: analysis of small RNA sequencing data and microRNA modifications.

    Science.gov (United States)

    Vitsios, Dimitrios M; Enright, Anton J

    2015-10-15

    Chimira is a web-based system for microRNA (miRNA) analysis from small RNA-Seq data. Sequences are automatically cleaned, trimmed, size selected and mapped directly to miRNA hairpin sequences. This generates count-based miRNA expression data for subsequent statistical analysis. Moreover, it is capable of identifying epi-transcriptomic modifications in the input sequences. Supported modification types include multiple types of 3'-modifications (e.g. uridylation, adenylation), 5'-modifications and also internal modifications or variation (ADAR editing or single nucleotide polymorphisms). Besides cleaning and mapping of input sequences to miRNAs, Chimira provides a simple and intuitive set of tools for the analysis and interpretation of the results (see also Supplementary Material). These allow the visual study of the differential expression between two specific samples or sets of samples, the identification of the most highly expressed miRNAs within sample pairs (or sets of samples) and also the projection of the modification profile for specific miRNAs across all samples. Other tools have already been published in the past for various types of small RNA-Seq analysis, such as UEA workbench, seqBuster, MAGI, OASIS and CAP-miRSeq, CPSS for modifications identification. A comprehensive comparison of Chimira with each of these tools is provided in the Supplementary Material. Chimira outperforms all of these tools in total execution speed and aims to facilitate simple, fast and reliable analysis of small RNA-Seq data allowing also, for the first time, identification of global microRNA modification profiles in a simple intuitive interface. Chimira has been developed as a web application and it is accessible here: http://www.ebi.ac.uk/research/enright/software/chimira. aje@ebi.ac.uk Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press.

  9. Coronavirus minus-strand RNA synthesis and effect of cycloheximide on coronavirus RNA synthesis

    International Nuclear Information System (INIS)

    Sawicki, S.G.; Sawicki, D.L.

    1986-01-01

    The temporal sequence of coronavirus plus-strand and minus-strand RNA synthesis was determined in 17CL1 cells infected with the A59 strain of mouse hepatitis virus (MHV). MHV-induced fusion was prevented by keeping the pH of the medium below pH 6.8. This had no effect on the MHV replication cycle, but gave 5- to 10-fold-greater titers of infectious virus and delayed the detachment of cells from the monolayer which permitted viral RNA synthesis to be studied conveniently until at least 10 h postinfection. Seven species of poly(A)-containing viral RNAs were synthesized at early and late times infection, in nonequal but constant ratios. MHV minus-strand RNA synthesis was first detected at about 3 h after infection and was found exclusively in the viral replicative intermediates and was not detected in 60S single-stranded form in infected cells. Early in the replication cycle, from 45 to 65% of the [ 3 H]uridine pulse-labeled RF core of purified MHV replicative intermediates was in minus-strand RNA. The rate of minus-strand synthesis peaked at 5 to 6 h postinfection and then declined to about 20% of the maximum rate. The addition of cycloheximide before 3 h postinfection prevented viral RNA synthesis, whereas the addition of cycloheximide after viral RNA synthesis had begun resulted in the inhibition of viral RNA synthesis. The synthesis of both genome and subgenomic mRNAs and of viral minus strands required continued protein synthesis, and minis-strand RNA synthesis was three- to fourfold more sensitive to inhibition of cycloheximide than was plus-strand synthesis

  10. Ms1, a novel sRNA interacting with the RNA polymerase core in mycobacteria

    Czech Academy of Sciences Publication Activity Database

    Hnilicová, Jarmila; Jirát-Matějčková, Jitka; Šiková, Michaela; Pospíšil, Jiří; Halada, Petr; Pánek, Josef; Krásný, Libor

    2014-01-01

    Roč. 42, č. 18 (2014), s. 11763-11776 ISSN 0305-1048 R&D Projects: GA ČR(CZ) GBP305/12/G034; GA ČR GP13-27150P Grant - others:Magistrát hl. m. P.(CZ) CZ.2.16/3.1.00/24023 Institutional support: RVO:61388971 Keywords : ESCHERICHIA-COLI * 6S RNA * NONCODING RNA Subject RIV: EE - Microbiology, Virology Impact factor: 9.112, year: 2014

  11. Heart structure-specific transcriptomic atlas reveals conserved microRNA-mRNA interactions.

    Science.gov (United States)

    Vacchi-Suzzi, Caterina; Hahne, Florian; Scheubel, Philippe; Marcellin, Magali; Dubost, Valerie; Westphal, Magdalena; Boeglen, Catherine; Büchmann-Møller, Stine; Cheung, Ming Sin; Cordier, André; De Benedetto, Christopher; Deurinck, Mark; Frei, Moritz; Moulin, Pierre; Oakeley, Edward; Grenet, Olivier; Grevot, Armelle; Stull, Robert; Theil, Diethilde; Moggs, Jonathan G; Marrer, Estelle; Couttet, Philippe

    2013-01-01

    MicroRNAs are short non-coding RNAs that regulate gene expression at the post-transcriptional level and play key roles in heart development and cardiovascular diseases. Here, we have characterized the expression and distribution of microRNAs across eight cardiac structures (left and right ventricles, apex, papillary muscle, septum, left and right atrium and valves) in rat, Beagle dog and cynomolgus monkey using microRNA sequencing. Conserved microRNA signatures enriched in specific heart structures across these species were identified for cardiac valve (miR-let-7c, miR-125b, miR-127, miR-199a-3p, miR-204, miR-320, miR-99b, miR-328 and miR-744) and myocardium (miR-1, miR-133b, miR-133a, miR-208b, miR-30e, miR-499-5p, miR-30e*). The relative abundance of myocardium-enriched (miR-1) and valve-enriched (miR-125b-5p and miR-204) microRNAs was confirmed using in situ hybridization. MicroRNA-mRNA interactions potentially relevant for cardiac functions were explored using anti-correlation expression analysis and microRNA target prediction algorithms. Interactions between miR-1/Timp3, miR-125b/Rbm24, miR-204/Tgfbr2 and miR-208b/Csnk2a2 were identified and experimentally investigated in human pulmonary smooth muscle cells and luciferase reporter assays. In conclusion, we have generated a high-resolution heart structure-specific mRNA/microRNA expression atlas for three mammalian species that provides a novel resource for investigating novel microRNA regulatory circuits involved in cardiac molecular physiopathology.

  12. Heart structure-specific transcriptomic atlas reveals conserved microRNA-mRNA interactions.

    Directory of Open Access Journals (Sweden)

    Caterina Vacchi-Suzzi

    Full Text Available MicroRNAs are short non-coding RNAs that regulate gene expression at the post-transcriptional level and play key roles in heart development and cardiovascular diseases. Here, we have characterized the expression and distribution of microRNAs across eight cardiac structures (left and right ventricles, apex, papillary muscle, septum, left and right atrium and valves in rat, Beagle dog and cynomolgus monkey using microRNA sequencing. Conserved microRNA signatures enriched in specific heart structures across these species were identified for cardiac valve (miR-let-7c, miR-125b, miR-127, miR-199a-3p, miR-204, miR-320, miR-99b, miR-328 and miR-744 and myocardium (miR-1, miR-133b, miR-133a, miR-208b, miR-30e, miR-499-5p, miR-30e*. The relative abundance of myocardium-enriched (miR-1 and valve-enriched (miR-125b-5p and miR-204 microRNAs was confirmed using in situ hybridization. MicroRNA-mRNA interactions potentially relevant for cardiac functions were explored using anti-correlation expression analysis and microRNA target prediction algorithms. Interactions between miR-1/Timp3, miR-125b/Rbm24, miR-204/Tgfbr2 and miR-208b/Csnk2a2 were identified and experimentally investigated in human pulmonary smooth muscle cells and luciferase reporter assays. In conclusion, we have generated a high-resolution heart structure-specific mRNA/microRNA expression atlas for three mammalian species that provides a novel resource for investigating novel microRNA regulatory circuits involved in cardiac molecular physiopathology.

  13. ARMOUR – A Rice miRNA: mRNA Interaction Resource

    OpenAIRE

    Neeti Sanan-Mishra; Anita Tripathi; Kavita Goswami; Rohit N. Shukla; Madavan Vasudevan; Hitesh Goswami

    2018-01-01

    ARMOUR was developed as ARice miRNA:mRNA interaction resource. This informative and interactive database includes the experimentally validated expression profiles of miRNAs under different developmental and abiotic stress conditions across seven Indian rice cultivars. This comprehensive database covers 689 known and 1664 predicted novel miRNAs and their expression profiles in more than 38 different tissues or conditions along with their predicted/known target transcripts. The understanding of...

  14. Intracellular coordination of potyviral RNA functions in infection

    Directory of Open Access Journals (Sweden)

    Kristiina eMäkinen

    2014-03-01

    Full Text Available Abstract Establishment of an infection cycle requires mechanisms to allocate the genomes of (+-stranded RNA viruses in a balanced ratio to translation, replication, encapsidation, and movement, as well as mechanisms to prevent translocation of viral RNA (vRNA to cellular RNA degradation pathways. The ratio of vRNA allocated to various functions is likely balanced by the availability of regulatory proteins or competition of the interaction sites within regulatory ribonucleoprotein (RNP complexes. Due to the transient nature of viral processes and the interdependency between vRNA pathways, it is technically demanding to work out the exact molecular mechanisms underlying vRNA regulation. A substantial number of viral and host proteins have been identified that facilitate the steps that lead to the assembly of a functional potyviral RNA replication complex and their fusion with chloroplasts. Simultaneously with on-going viral replication, part of the replicated potyviral RNA enters movement pathways. Although not much is known about the processes of potyviral RNA release from viral replication complexes (VRCs, the molecular interactions involved in these processes determine the fate of the replicated vRNA. Some viral and host cell proteins have been described that direct replicated potyviral RNA to translation to enable potyviral gene expression and productive infection. The antiviral defense of the cell causes vRNA degradation by RNA silencing. We hypothesize that also plant pathways involved in mRNA decay may have a role in the coordination of potyviral RNA expression. In this review, we discuss the roles of different potyviral and host proteins in the coordination of various potyviral RNA functions.

  15. Intracellular coordination of potyviral RNA functions in infection.

    Science.gov (United States)

    Mäkinen, Kristiina; Hafrén, Anders

    2014-01-01

    Establishment of an infection cycle requires mechanisms to allocate the genomes of (+)-stranded RNA viruses in a balanced ratio to translation, replication, encapsidation, and movement, as well as mechanisms to prevent translocation of viral RNA (vRNA) to cellular RNA degradation pathways. The ratio of vRNA allocated to various functions is likely balanced by the availability of regulatory proteins or competition of the interaction sites within regulatory ribonucleoprotein complexes. Due to the transient nature of viral processes and the interdependency between vRNA pathways, it is technically demanding to work out the exact molecular mechanisms underlying vRNA regulation. A substantial number of viral and host proteins have been identified that facilitate the steps that lead to the assembly of a functional potyviral RNA replication complex and their fusion with chloroplasts. Simultaneously with on-going viral replication, part of the replicated potyviral RNA enters movement pathways. Although not much is known about the processes of potyviral RNA release from viral replication complexes, the molecular interactions involved in these processes determine the fate of the replicated vRNA. Some viral and host cell proteins have been described that direct replicated potyviral RNA to translation to enable potyviral gene expression and productive infection. The antiviral defense of the cell causes vRNA degradation by RNA silencing. We hypothesize that also plant pathways involved in mRNA decay may have a role in the coordination of potyviral RNA expression. In this review, we discuss the roles of different potyviral and host proteins in the coordination of various potyviral RNA functions.

  16. Exportin-5 mediates nuclear export of SRP RNA in vertebrates.

    Science.gov (United States)

    Takeiwa, Toshihiko; Taniguchi, Ichiro; Ohno, Mutsuhito

    2015-04-01

    The signal recognition particle is a ribonucleoprotein complex that is essential for the translocation of nascent proteins into the endoplasmic reticulum. It has been shown that the RNA component (SRP RNA) is exported from the nucleus by CRM1 in the budding yeast. However, how SRP RNA is exported in higher species has been elusive. Here, we show that SRP RNA does not use the CRM1 pathway in Xenopus oocytes. Instead, SRP RNA uses the same export pathway as pre-miRNA and tRNA as showed by cross-competition experiments. Consistently, the recombinant Exportin-5 protein specifically stimulated export of SRP RNA as well as of pre-miRNA and tRNA, whereas an antibody raised against Exportin-5 specifically inhibited export of the same RNA species. Moreover, biotinylated SRP RNA can pull down Exportin-5 but not CRM1 from HeLa cell nuclear extracts in a RanGTP-dependent manner. These results, taken together, strongly suggest that the principal export receptor for SRP RNA in vertebrates is Exportin-5 unlike in the budding yeast. © 2015 The Authors. Genes to Cells published by Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

  17. Size, Shape, and Sequence-Dependent Immunogenicity of RNA Nanoparticles.

    Science.gov (United States)

    Guo, Sijin; Li, Hui; Ma, Mengshi; Fu, Jian; Dong, Yizhou; Guo, Peixuan

    2017-12-15

    RNA molecules have emerged as promising therapeutics. Like all other drugs, the safety profile and immune response are important criteria for drug evaluation. However, the literature on RNA immunogenicity has been controversial. Here, we used the approach of RNA nanotechnology to demonstrate that the immune response of RNA nanoparticles is size, shape, and sequence dependent. RNA triangle, square, pentagon, and tetrahedron with same shape but different sizes, or same size but different shapes were used as models to investigate the immune response. The levels of pro-inflammatory cytokines induced by these RNA nanoarchitectures were assessed in macrophage-like cells and animals. It was found that RNA polygons without extension at the vertexes were immune inert. However, when single-stranded RNA with a specific sequence was extended from the vertexes of RNA polygons, strong immune responses were detected. These immunostimulations are sequence specific, because some other extended sequences induced little or no immune response. Additionally, larger-size RNA square induced stronger cytokine secretion. 3D RNA tetrahedron showed stronger immunostimulation than planar RNA triangle. These results suggest that the immunogenicity of RNA nanoparticles is tunable to produce either a minimal immune response that can serve as safe therapeutic vectors, or a strong immune response for cancer immunotherapy or vaccine adjuvants. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Size, Shape, and Sequence-Dependent Immunogenicity of RNA Nanoparticles

    Directory of Open Access Journals (Sweden)

    Sijin Guo

    2017-12-01

    Full Text Available RNA molecules have emerged as promising therapeutics. Like all other drugs, the safety profile and immune response are important criteria for drug evaluation. However, the literature on RNA immunogenicity has been controversial. Here, we used the approach of RNA nanotechnology to demonstrate that the immune response of RNA nanoparticles is size, shape, and sequence dependent. RNA triangle, square, pentagon, and tetrahedron with same shape but different sizes, or same size but different shapes were used as models to investigate the immune response. The levels of pro-inflammatory cytokines induced by these RNA nanoarchitectures were assessed in macrophage-like cells and animals. It was found that RNA polygons without extension at the vertexes were immune inert. However, when single-stranded RNA with a specific sequence was extended from the vertexes of RNA polygons, strong immune responses were detected. These immunostimulations are sequence specific, because some other extended sequences induced little or no immune response. Additionally, larger-size RNA square induced stronger cytokine secretion. 3D RNA tetrahedron showed stronger immunostimulation than planar RNA triangle. These results suggest that the immunogenicity of RNA nanoparticles is tunable to produce either a minimal immune response that can serve as safe therapeutic vectors, or a strong immune response for cancer immunotherapy or vaccine adjuvants.

  19. Structural imprints in vivo decode RNA regulatory mechanisms.

    Science.gov (United States)

    Spitale, Robert C; Flynn, Ryan A; Zhang, Qiangfeng Cliff; Crisalli, Pete; Lee, Byron; Jung, Jong-Wha; Kuchelmeister, Hannes Y; Batista, Pedro J; Torre, Eduardo A; Kool, Eric T; Chang, Howard Y

    2015-03-26

    Visualizing the physical basis for molecular behaviour inside living cells is a great challenge for biology. RNAs are central to biological regulation, and the ability of RNA to adopt specific structures intimately controls every step of the gene expression program. However, our understanding of physiological RNA structures is limited; current in vivo RNA structure profiles include only two of the four nucleotides that make up RNA. Here we present a novel biochemical approach, in vivo click selective 2'-hydroxyl acylation and profiling experiment (icSHAPE), which enables the first global view, to our knowledge, of RNA secondary structures in living cells for all four bases. icSHAPE of the mouse embryonic stem cell transcriptome versus purified RNA folded in vitro shows that the structural dynamics of RNA in the cellular environment distinguish different classes of RNAs and regulatory elements. Structural signatures at translational start sites and ribosome pause sites are conserved from in vitro conditions, suggesting that these RNA elements are programmed by sequence. In contrast, focal structural rearrangements in vivo reveal precise interfaces of RNA with RNA-binding proteins or RNA-modification sites that are consistent with atomic-resolution structural data. Such dynamic structural footprints enable accurate prediction of RNA-protein interactions and N(6)-methyladenosine (m(6)A) modification genome wide. These results open the door for structural genomics of RNA in living cells and reveal key physiological structures controlling gene expression.

  20. Re-inspection of small RNA sequence datasets reveals several novel human miRNA genes.

    Directory of Open Access Journals (Sweden)

    Thomas Birkballe Hansen

    Full Text Available BACKGROUND: miRNAs are key players in gene expression regulation. To fully understand the complex nature of cellular differentiation or initiation and progression of disease, it is important to assess the expression patterns of as many miRNAs as possible. Thereby, identifying novel miRNAs is an essential prerequisite to make possible a comprehensive and coherent understanding of cellular biology. METHODOLOGY/PRINCIPAL FINDINGS: Based on two extensive, but previously published, small RNA sequence datasets from human embryonic stem cells and human embroid bodies, respectively [1], we identified 112 novel miRNA-like structures and were able to validate miRNA processing in 12 out of 17 investigated cases. Several miRNA candidates were furthermore substantiated by including additional available small RNA datasets, thereby demonstrating the power of combining datasets to identify miRNAs that otherwise may be assigned as experimental noise. CONCLUSIONS/SIGNIFICANCE: Our analysis highlights that existing datasets are not yet exhaustedly studied and continuous re-analysis of the available data is important to uncover all features of small RNA sequencing.

  1. Retroviral Gag protein-RNA interactions: Implications for specific genomic RNA packaging and virion assembly.

    Science.gov (United States)

    Olson, Erik D; Musier-Forsyth, Karin

    2018-03-31

    Retroviral Gag proteins are responsible for coordinating many aspects of virion assembly. Gag possesses two distinct nucleic acid binding domains, matrix (MA) and nucleocapsid (NC). One of the critical functions of Gag is to specifically recognize, bind, and package the retroviral genomic RNA (gRNA) into assembling virions. Gag interactions with cellular RNAs have also been shown to regulate aspects of assembly. Recent results have shed light on the role of MA and NC domain interactions with nucleic acids, and how they jointly function to ensure packaging of the retroviral gRNA. Here, we will review the literature regarding RNA interactions with NC, MA, as well as overall mechanisms employed by Gag to interact with RNA. The discussion focuses on human immunodeficiency virus type-1, but other retroviruses will also be discussed. A model is presented combining all of the available data summarizing the various factors and layers of selection Gag employs to ensure specific gRNA packaging and correct virion assembly. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Structural basis of RNA folding and recognition in an AMP-RNA aptamer complex.

    Science.gov (United States)

    Jiang, F; Kumar, R A; Jones, R A; Patel, D J

    1996-07-11

    The catalytic properties of RNA and its well known role in gene expression and regulation are the consequence of its unique solution structures. Identification of the structural determinants of ligand recognition by RNA molecules is of fundamental importance for understanding the biological functions of RNA, as well as for the rational design of RNA Sequences with specific catalytic activities. Towards this latter end, Szostak et al. used in vitro selection techniques to isolate RNA sequences ('aptamers') containing a high-affinity binding site for ATP, the universal currency of cellular energy, and then used this motif to engineer ribozymes with polynucleotide kinase activity. Here we present the solution structure, as determined by multidimensional NMR spectroscopy and molecular dynamics calculations, of both uniformly and specifically 13C-, 15N-labelled 40-mer RNA containing the ATP-binding motif complexed with AMP. The aptamer adopts an L-shaped structure with two nearly orthogonal stems, each capped proximally by a G x G mismatch pair, binding the AMP ligand at their junction in a GNRA-like motif.

  3. A simple and robust vector-based shRNA expression system used for RNA interference.

    Science.gov (United States)

    Wang, Xue-jun; Li, Ying; Huang, Hai; Zhang, Xiu-juan; Xie, Pei-wen; Hu, Wei; Li, Dan-dan; Wang, Sheng-qi

    2013-01-01

    RNA interference (RNAi) mediated by small interfering RNAs (siRNAs) or short hairpin RNAs (shRNAs) has become a powerful genetic tool for conducting functional studies. Previously, vector-based shRNA-expression strategies capable of inducing RNAi in viable cells have been developed, however, these vector systems have some disadvantages, either because they were error-prone or cost prohibitive. In this report we described the development of a simple, robust shRNA expression system utilizing 1 long oligonucleotide or 2 short oligonucleotides for half the cost of conventional shRNA construction methods and with a >95% cloning success rate. The shRNA loop sequence and stem structure were also compared and carefully selected for better RNAi efficiency. Furthermore, an easier strategy was developed based on isocaudomers which permit rapid combination of the most efficient promoter-shRNA cassettes. Finally, using this method, the conservative target sites for hepatitis B virus (HBV) knockdown were systemically screened and HBV antigen expression shown to be successfully suppressed in the presence of connected multiple shRNAs both in vitro and in vivo. This novel design describes an inexpensive and effective way to clone and express single or multiple shRNAs from the same vector with the capacity for potent and effective silencing of target genes.

  4. A simple and robust vector-based shRNA expression system used for RNA interference.

    Directory of Open Access Journals (Sweden)

    Xue-jun Wang

    Full Text Available BACKGROUND: RNA interference (RNAi mediated by small interfering RNAs (siRNAs or short hairpin RNAs (shRNAs has become a powerful genetic tool for conducting functional studies. Previously, vector-based shRNA-expression strategies capable of inducing RNAi in viable cells have been developed, however, these vector systems have some disadvantages, either because they were error-prone or cost prohibitive. RESULTS: In this report we described the development of a simple, robust shRNA expression system utilizing 1 long oligonucleotide or 2 short oligonucleotides for half the cost of conventional shRNA construction methods and with a >95% cloning success rate. The shRNA loop sequence and stem structure were also compared and carefully selected for better RNAi efficiency. Furthermore, an easier strategy was developed based on isocaudomers which permit rapid combination of the most efficient promoter-shRNA cassettes. Finally, using this method, the conservative target sites for hepatitis B virus (HBV knockdown were systemically screened and HBV antigen expression shown to be successfully suppressed in the presence of connected multiple shRNAs both in vitro and in vivo. CONCLUSION: This novel design describes an inexpensive and effective way to clone and express single or multiple shRNAs from the same vector with the capacity for potent and effective silencing of target genes.

  5. A microRNA feedback loop regulates global microRNA abundance during aging.

    Science.gov (United States)

    Inukai, Sachi; Pincus, Zachary; de Lencastre, Alexandre; Slack, Frank J

    2018-02-01

    Expression levels of many microRNAs (miRNAs) change during aging, notably declining globally in a number of organisms and tissues across taxa. However, little is known about the mechanisms or the biological relevance for this change. We investigated the network of genes that controls miRNA transcription and processing during C. elegans aging. We found that miRNA biogenesis genes are highly networked with transcription factors and aging-associated miRNAs. In particular, miR-71, known to influence life span and itself up-regulated during aging, represses alg-1 /Argonaute expression post-transcriptionally during aging. Increased ALG-1 abundance in mir-71 loss-of-function mutants led to globally increased miRNA expression. Interestingly, these mutants demonstrated widespread mRNA expression dysregulation and diminished levels of variability both in gene expression and in overall life span. Thus, the progressive molecular decline often thought to be the result of accumulated damage over an organism's life may be partially explained by a miRNA-directed mechanism of age-associated decline. © 2018 Inukai et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  6. Computational prediction of miRNA genes from small RNA sequencing data

    Directory of Open Access Journals (Sweden)

    Wenjing eKang

    2015-01-01

    Full Text Available Next-generation sequencing now for the first time allows researchers to gauge the depth and variation of entire transcriptomes. However, now as rare transcripts can be detected that are present in cells at single copies, more advanced computational tools are needed to accurately annotate and profile them. miRNAs are 22 nucleotide small RNAs (sRNAs that post-transcriptionally reduce the output of protein coding genes. They have established roles in numerous biological processes, including cancers and other diseases. During miRNA biogenesis, the sRNAs are sequentially cleaved from precursor molecules that have a characteristic hairpin RNA structure. The vast majority of new miRNA genes that are discovered are mined from small RNA sequencing (sRNA-seq, which can detect more than a billion RNAs in a single run. However, given that many of the detected RNAs are degradation products from all types of transcripts, the accurate identification of miRNAs remain a non-trivial computational problem. Here we review the tools available to predict animal miRNAs from sRNA sequencing data. We present tools for generalist and specialist use cases, including prediction from massively pooled data or in species without reference genome. We also present wet-lab methods used to validate predicted miRNAs, and approaches to computationally benchmark prediction accuracy. For each tool, we reference validation experiments and benchmarking efforts. Last, we discuss the future of the field.

  7. Protection and systemic translocation of siRNA following oral administration of chitosan/siRNA nanoparticles

    DEFF Research Database (Denmark)

    Gonzalez, Borja Ballarin; Dagnæs-Hansen, Frederik; Fenton, Robert A.

    2013-01-01

    , gastrointestinal (GI) deposition, and translocation into peripheral tissue of nonmodified siRNA after oral gavage of chitosan/siRNA nanoparticles in mice. In contrast to naked siRNA, retained structural integrity and deposition in the stomach, proximal and distal small intestine, and colon was observed at 1 and 5...... hours for siRNA within nanoparticles. Furthermore, histological detection of fluorescent siRNA at the apical regions of the intestinal epithelium suggests mucoadhesion provided by chitosan. Detection of intact siRNA in the liver, spleen, and kidney was observed 1 hour after oral gavage, with an organ...

  8. Presence of albumin mRNA precursors in nuclei of analbuminemic rat liver lacking cytoplasmic albumin mRNA.

    OpenAIRE

    Esumi, H; Takahashi, Y; Sekiya, T; Sato, S; Nagase, S; Sugimura, T

    1982-01-01

    Analbuminemic rats, which lack serum albumin, were previously found to have no albumin mRNA in the cytoplasm of the liver. In the present study, the existence of nuclear albumin mRNA precursors in the liver of analbuminemic rats was examined by RNA X cDNA hybridization kinetics. Albumin mRNA precursors were present in the nuclei of analbuminemic rat liver at almost normal levels, despite the absence of albumin mRNA from the cytoplasm. Nuclear RNA of analbuminemic rat liver was subjected to el...

  9. Generation of RNA in abiotic conditions.

    Science.gov (United States)

    di Mauro, Ernesto

    Generation of RNA in abiotic conditions. Ernesto Di Mauro Dipartimento di Genetica Bi-ologia Molecolare, Universit` "Sapienza" Roma, Italy. a At least four conditions must be satisfied for the spontaneous generation of (pre)-genetic poly-mers: 1) availability of precursors that are activated enough to spontaneously polymerize. Preliminary studies showed that (a) nucleic bases and acyclonucleosides can be synthesized from formamide H2NCOH by simply heating with prebiotically available mineral catalysts [last reviewed in (1)], and that b) nucleic bases can be phosphorylated in every possible posi-tion [2'; 3'; 5'; cyclic 2',3'; cyclic 3',5' (2)]. The higher stability of the cyclic forms allows their accumulation. 2) A polymerization mechanism. A reaction showing the formation of RNA polymers starting from prebiotically plausible precursors (3',5' cyclic GMP and 3', 5'cyclic AMP) was recently reported (3). Polymerization in these conditions is thermodynamically up-hill and an equilibrium is attained that limits the maximum length of the polymer produced to about 40 nucleotides for polyG and 100 nucleotides for polyA. 3) Ligation of the synthesized oligomers. If this type of reaction could occur according to a terminal-joining mechanism and could generate canonical 3',5' phosphodiester bonds, exponential growth would be obtained of the generated oligomers. This type of reaction has been reported (4) , limited to homogeneous polyA sequences and leading to the production of polyA dimers and tetramers. What is still missing are: 4) mechanisms that provide the proof of principle for the generation of sequence complexity. We will show evidence for two mechanisms providing this proof of principle for simple complementary sequences. Namely: abiotic sequence complementary-driven terminal ligation and sequence-complementary terminal growth. In conclusion: all the steps leading to the generation of RNA in abiotic conditions are satisfied. (1) R Saladino, C Crestini, F

  10. RNA amplification for successful gene profiling analysis

    Directory of Open Access Journals (Sweden)

    Wang Ena

    2005-07-01

    Full Text Available Abstract The study of clinical samples is often limited by the amount of material available to study. While proteins cannot be multiplied in their natural form, DNA and RNA can be amplified from small specimens and used for high-throughput analyses. Therefore, genetic studies offer the best opportunity to screen for novel insights of human pathology when little material is available. Precise estimates of DNA copy numbers in a given specimen are necessary. However, most studies investigate static variables such as the genetic background of patients or mutations within pathological specimens without a need to assess proportionality of expression among different genes throughout the genome. Comparative genomic hybridization of DNA samples represents a crude exception to this rule since genomic amplification or deletion is compared among different specimens directly. For gene expression analysis, however, it is critical to accurately estimate the proportional expression of distinct RNA transcripts since such proportions directly govern cell function by modulating protein expression. Furthermore, comparative estimates of relative RNA expression at different time points portray the response of cells to environmental stimuli, indirectly informing about broader biological events affecting a particular tissue in physiological or pathological conditions. This cognitive reaction of cells is similar to the detection of electroencephalographic patterns which inform about the status of the brain in response to external stimuli. As our need to understand human pathophysiology at the global level increases, the development and refinement of technologies for high fidelity messenger RNA amplification have become the focus of increasing interest during the past decade. The need to increase the abundance of RNA has been met not only for gene specific amplification, but, most importantly for global transcriptome wide, unbiased amplification. Now gene

  11. Enzymatic synthesis of tRNA-peptide conjugates and spectroscopic studies of fluorine-modified RNA

    International Nuclear Information System (INIS)

    Graber, D.

    2010-01-01

    The research presented in this thesis concerns the enzymatic synthesis of artificially modified tRNA, in particular the preparation of non-hydrolysable tRNA-peptide conjugates. Another focus is on NMR-spectroscopic investigations of fluorine-modified RNA. In both projects, chemical methods were developed to address specific RNA-biological research questions. In the first part of this thesis the preparation of tRNA-peptide conjugates with a non-hydrolysable 3'-amide linkage is presented. These molecules are of high relevance for the characterization of ribosomal processes that occur in the peptidyl transferase center (such as peptide bond formation, peptide release, or translocation) using X-ray crystallography and biochemical methods. First, a novel concept to prepare chemically modified ('labeled') tRNA was elaborated based on the combination of solid-phase synthesis and enzymatic ligation. Thereby, a variety of differently labeled tRNAs was achieved. Moreover, the most successful high-yield ligation sites were identified to be situated within the TΨ C-loop. Optimization of the synthesis and the corresponding HPLC-purification of the conjugates were initially conducted with puromycin derivatized tRNA. In the course of this project, also two tRNAs with a ribose 3'-amino group at the terminal adenosine A76 were synthesized. For that purpose a protection group pattern had to be developed to obtain a functionalized solid-support bound to 3'-amino-3'-deoxyadenosine which was appropriate for RNA solid-phase synthesis. The successful preparation of tRNA-peptide conjugates was accomplished in cooperation with Holger Moroder and Jessica Steger (Micura group) who contributed short synthetic RNA-peptide conjugates. These fragments represented the tRNA 3'-termini that were required for exploring the new ligation strategies for non-hydrolisable tRNA - a main aim of this thesis. If the 5'-fragments are synthesized by solid-phase synthesis or in vitro transcription they do not

  12. Conserved and variable domains of RNase MRP RNA.

    Science.gov (United States)

    Dávila López, Marcela; Rosenblad, Magnus Alm; Samuelsson, Tore

    2009-01-01

    Ribonuclease MRP is a eukaryotic ribonucleoprotein complex consisting of one RNA molecule and 7-10 protein subunits. One important function of MRP is to catalyze an endonucleolytic cleavage during processing of rRNA precursors. RNase MRP is evolutionary related to RNase P which is critical for tRNA processing. A large number of MRP RNA sequences that now are available have been used to identify conserved primary and secondary structure features of the molecule. MRP RNA has structural features in common with P RNA such as a conserved catalytic core, but it also has unique features and is characterized by a domain highly variable between species. Information regarding primary and secondary structure features is of interest not only in basic studies of the function of MRP RNA, but also because mutations in the RNA give rise to human genetic diseases such as cartilage-hair hypoplasia.

  13. CRISPR/Cas13 as a Tool for RNA Interference

    KAUST Repository

    Ali, Zahir; Mahas, Ahmed; Mahfouz, Magdy M.

    2018-01-01

    Almost all biological processes involve RNA, making it crucial to develop tools for manipulation of the transcriptome. The bacterial CRISPR/Cas13 system was recently rewired to facilitate RNA manipulation in eukaryotes, including plants. We discuss

  14. tRNA--the golden standard in molecular biology.

    Science.gov (United States)

    Barciszewska, Mirosława Z; Perrigue, Patrick M; Barciszewski, Jan

    2016-01-01

    Transfer RNAs (tRNAs) represent a major class of RNA molecules. Their primary function is to help decode a messenger RNA (mRNA) sequence in order to synthesize protein and thus ensures the precise translation of genetic information that is imprinted in DNA. The discovery of tRNA in the late 1950's provided critical insight into a genetic machinery when little was known about the central dogma of molecular biology. In 1965, Robert Holley determined the first nucleotide sequence of alanine transfer RNA (tRNA(Ala)) which earned him the 1968 Nobel Prize in Physiology or Medicine. Today, tRNA is one of the best described and characterized biological molecules. Here we review some of the key historical events in tRNA research which led to breakthrough discoveries and new developments in molecular biology.

  15. Suppressors of RNA silencing encoded by tomato leaf curl ...

    Indian Academy of Sciences (India)

    2013-01-06

    Jan 6, 2013 ... Virus encoded RNA-silencing suppressors (RSSs) are the key components evolved by the viruses to ... severe disease symptom in the host (Briddon et al. ..... Voinnet O 2001 RNA silencing as a plant immune system against.

  16. Intervention of radiation‐induced skin fibrosis by RNA interference

    DEFF Research Database (Denmark)

    Nawroth, Isabel

    ‐α (TNFα) production by macrophages might promote RIF. RNA interference (RNAi) is an evolutionary conserved gene‐silencing mechanism capable of degrading mRNA containing a homologous sequence to an exogenously introduced double stranded small interfering RNA (siRNA). These siRNAs can induce RNAi...... and inhibit the expression of target proteins. Therefore, siRNAs are considered as promising therapeutics for treatment of various diseases including genetic and viral diseases, and cancer. In this study, the therapeutic potential of RNA interference was investigated as an intervention strategy for radiation......‐induced skin fibrosis. Chitosan‐based nanoparticles (or polyplexes) formed by self‐assembly with siRNA were applied to overcome extracellular and intracellular barriers and deliver siRNA site‐specific. In this work we show that intraperitoneal administration of chitosan/DsiRNA nanoparticles targeting TNFα...

  17. Mechanisms of human immunodeficiency virus type 2 RNA packaging

    DEFF Research Database (Denmark)

    Ni, Na; Nikolaitchik, Olga A; Dilley, Kari A

    2011-01-01

    do not support the cis-packaging hypothesis but instead indicate that trans packaging is the major mechanism of HIV-2 RNA packaging. To further characterize the mechanisms of HIV-2 RNA packaging, we visualized HIV-2 RNA in individual particles by using fluorescent protein-tagged RNA-binding proteins......Human immunodeficiency virus type 2 (HIV-2) has been reported to have a distinct RNA packaging mechanism, referred to as cis packaging, in which Gag proteins package the RNA from which they were translated. We examined the progeny generated from dually infected cell lines that contain two HIV-2...... proviruses, one with a wild-type gag/gag-pol and the other with a mutant gag that cannot express functional Gag/Gag-Pol. Viral titers and RNA analyses revealed that mutant viral RNAs can be packaged at efficiencies comparable to that of viral RNA from which wild-type Gag/Gag-Pol is translated. These results...

  18. Developmental regulation of Xenopus 5S RNA genes

    International Nuclear Information System (INIS)

    Wormington, W.M.; Schlissel, M.; Brown, D.D.

    1983-01-01

    In this paper it is demonstrated that the actively transcribed fraction of somatic 5S RNA genes in somatic-cell chromatin is complexed stably with all required factors, so that the addition of only purified RNA polymerase III is needed to support somatic 5S RNA synthesis in vitro. Oocyte 5S RNA genes in somatic-cell chromatin appear to lack these factors, since their activation in salt-washed somatic-cell chromatin depends on exogeneous transciption factors in addition to RNA polymerase III. The developmental control of 5S RNA genes is established over a period beginning with the onset of 5S RNA synthesis in late blastula embryos, and this control is reproduced in vitro using chromatin templates isolated from appropriate stages. We propose that a decreasing concentration of the 5S-specific transcription factor during embryogenesis contributes to the inactivation of oocyte 5S RNA genes. 12 references, 4 figures, 1 table

  19. RNA synthesis during cleavage of the Lymnaea egg

    NARCIS (Netherlands)

    Biggelaar, J.A.M. van den

    In eggs of Lymnaea RNA synthesis can be detected autoradiographically from the 8- to the 16-cell stage. From the 16- to the 24-cell stage distinct nucleoli reappear which are immediately engaged in RNA synthesis.

  20. DMPD: TLR ignores methylated RNA? [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16111629 TLR ignores methylated RNA? Ishii KJ, Akira S. Immunity. 2005 Aug;23(2):11...1-3. (.png) (.svg) (.html) (.csml) Show TLR ignores methylated RNA? PubmedID 16111629 Title TLR ignores methylated