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Kniert J, Lin QF, Shmulevitz M. Captivating Perplexities of Spinareovirinae 5' RNA Caps. Viruses 2021; 13:v13020294. [PMID: 33668598 PMCID: PMC7918360 DOI: 10.3390/v13020294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/08/2021] [Accepted: 02/08/2021] [Indexed: 11/16/2022] Open
Abstract
RNAs with methylated cap structures are present throughout multiple domains of life. Given that cap structures play a myriad of important roles beyond translation, such as stability and immune recognition, it is not surprising that viruses have adopted RNA capping processes for their own benefit throughout co-evolution with their hosts. In fact, that RNAs are capped was first discovered in a member of the Spinareovirinae family, Cypovirus, before these findings were translated to other domains of life. This review revisits long-past knowledge and recent studies on RNA capping among members of Spinareovirinae to help elucidate the perplex processes of RNA capping and functions of RNA cap structures during Spinareovirinae infection. The review brings to light the many uncertainties that remain about the precise capping status, enzymes that facilitate specific steps of capping, and the functions of RNA caps during Spinareovirinae replication.
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Tran AT, Xu W, Racine T, Silaghi DA, Coombs KM. Assignment of avian reovirus temperature-sensitive mutant recombination groups E, F, and G to genome segments. Virology 2008; 375:504-13. [PMID: 18353422 DOI: 10.1016/j.virol.2008.02.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2007] [Revised: 12/13/2007] [Accepted: 02/06/2008] [Indexed: 11/28/2022]
Abstract
Avian reoviruses (ARV) are less well understood than their mammalian counterparts. ARV are ubiquitous in commercial poultry and frequently isolated from acutely infected chickens. We previously described isolation of ARV temperature-sensitive (ts) mutants after nitrosoguanidine mutagenesis of wild-type ARV138, their assignment to 7 recombination groups (A-G), and genetic mapping of mutants in groups A-D to specific gene segments. For this study, wild-type serotype ARV176 was crossed with ts mutants tsE158 (Group E), tsF206 (Group F), or tsG247 (Group G) and reassortant progenies analyzed. Reassortant temperature-sensitivities were determined by efficiency of plating at permissive and non-permissive temperatures. Mapping results indicated tsE158, tsF206, and tsG247 mapped to the L1, S4, and L3 genes, respectively, which encode the lambdaA core shell, sigmaNS non-structural, and lambdaC core spike proteins, respectively. Specific amino acid substitutions in each mutant were determined and locations of structural protein alterations were placed within the 3-dimensional structure of homologous mammalian reovirus proteins. Mapping recombination groups E-G marks completion of gene assignments for all seven ts mutant groups previously generated.
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Affiliation(s)
- Anh T Tran
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada.
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3
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Conformational changes accompany activation of reovirus RNA-dependent RNA transcription. J Struct Biol 2008; 162:277-89. [PMID: 18321727 DOI: 10.1016/j.jsb.2008.01.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 12/07/2007] [Accepted: 01/17/2008] [Indexed: 12/28/2022]
Abstract
Many critical biologic processes involve dynamic interactions between proteins and nucleic acids. Such dynamic processes are often difficult to delineate by conventional static methods. For example, while a variety of nucleic acid polymerase structures have been determined at atomic resolution, the details of how some multi-protein transcriptase complexes actively produce mRNA, as well as conformational changes associated with activation of such complexes, remain poorly understood. The mammalian reovirus innermost capsid (core) manifests all enzymatic activities necessary to produce mRNA from each of the 10 encased double-stranded RNA genes. We used rapid freezing and electron cryo-microscopy to trap and visualize transcriptionally active reovirus core particles and compared them to inactive core images. Rod-like density centered within actively transcribing core spike channels was attributed to exiting nascent mRNA. Comparative radial density plots of active and inactive core particles identified several structural changes in both internal and external regions of the icosahedral core capsid. Inactive and transcriptionally active cores were partially digested with trypsin and identities of initial tryptic peptides determined by mass spectrometry. Differentially-digested peptides, which also suggest transcription-associated conformational changes, were placed within the known three-dimensional structures of major core proteins.
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Kim J, Parker JSL, Murray KE, Nibert ML. Nucleoside and RNA triphosphatase activities of orthoreovirus transcriptase cofactor mu2. J Biol Chem 2003; 279:4394-403. [PMID: 14613938 DOI: 10.1074/jbc.m308637200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mammalian Orthoreovirus (mORV) core particle is an icosahedral multienzyme complex for viral mRNA synthesis and provides a delimited system for mechanistic studies of that process. Previous genetic results have identified the mORV mu2 protein as a determinant of viral strain differences in the transcriptase and nucleoside triphosphatase activities of cores. New results in this report provided biochemical and genetic evidence that purified mu2 is itself a divalent cation-dependent nucleoside triphosphatase that can remove the 5' gamma-phosphate from RNA as well. Alanine substitutions in a putative nucleotide binding region of mu2 abrogated both functions but did not affect the purification profile of the protein or its known associations with microtubules and mORV microNS protein in vivo. In vitro microtubule binding by purified mu2 was also demonstrated and not affected by the mutations. Purified mu2 was further demonstrated to interact in vitro with the mORV RNA-dependent RNA polymerase, lambda3, and the presence of lambda3 mildly stimulated the triphosphatase activities of mu2. These findings confirm that mu2 is an enzymatic component of the mORV core and may contribute several possible functions to viral mRNA synthesis.
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Affiliation(s)
- Jonghwa Kim
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
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5
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Horscroft NJ, Roy P. NTP binding and phosphohydrolase activity associated with purified bluetongue virus non-structural protein NS2. J Gen Virol 2000; 81:1961-1965. [PMID: 10900034 DOI: 10.1099/0022-1317-81-8-1961] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The bluetongue virus ssRNA-binding protein, NS2, is a phosphoprotein that forms viral inclusion bodies in infected cells. Recombinant NS2 was expressed in the baculovirus expression system and purified to homogeneity from insect cells. Purified NS2 bound nucleosides. Further investigation revealed that the protein bound ATP and GTP and could hydrolyse both nucleosides to their corresponding NMPs, with a higher efficiency for the hydrolysis of ATP. The increased efficiency of hydrolysis of ATP correlated with a higher binding affinity of NS2 for ATP than GTP. Ca(2+), Mg(2+) and Mn(2+) were able to function as the required divalent cation in the reactions. The phosphohydrolase activity was not sensitive to ouabain, an inhibitor of cellular ATPases, suggesting that this activity was not the result of a cellular contaminant.
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Affiliation(s)
- Nigel J Horscroft
- NERC Institute of Virology and Environmental Microbiology, Mansfield Road, Oxford OX1 3SR, UK2
- Department of Biochemistry, Oxford University, Oxford OX1 3QU, UK1
| | - Polly Roy
- Department of Geographic Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA3
- NERC Institute of Virology and Environmental Microbiology, Mansfield Road, Oxford OX1 3SR, UK2
- Department of Biochemistry, Oxford University, Oxford OX1 3QU, UK1
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6
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Yue Z, Shatkin AJ. Enzymatic and control functions of reovirus structural proteins. Curr Top Microbiol Immunol 1998; 233:31-56. [PMID: 9599920 DOI: 10.1007/978-3-642-72092-5_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Z Yue
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ 08854-5638, USA
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7
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Bisaillon M, Lemay G. Characterization of the reovirus lambda1 protein RNA 5'-triphosphatase activity. J Biol Chem 1997; 272:29954-7. [PMID: 9368073 DOI: 10.1074/jbc.272.47.29954] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Characterization of the phosphohydrolytic activities of recombinant reovirus lambda1 protein demonstrates that, in addition to the previously reported nucleoside triphosphate phosphohydrolase and helicase activities, the protein also possesses RNA 5'-triphosphatase activity. This activity was absolutely dependent on the presence of a divalent cation, Mg2+ or Mn2+, and specifically removes the 5'-gamma-phosphate at the end of triphosphate-terminated RNAs. Kinetic competition analysis showed that nucleoside triphosphate phosphohydrolase and RNA 5'-triphosphatase reactions are carried out at a common active site. These results strongly support the idea that, in addition to its role as an RNA helicase during transcription of the viral genome, lambda1 also participates during formation of the cap structure at the 5' end of newly synthesized reovirus mRNAs. The lambda1 protein represents only the third RNA triphosphatase whose primary structure is known and the first described in a double-stranded RNA virus.
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Affiliation(s)
- M Bisaillon
- Département de Microbiologie et Immunologie, Université de Montréal, Montréal, Québec H3C 3J7, Canada
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Noble S, Nibert ML. Core protein mu2 is a second determinant of nucleoside triphosphatase activities by reovirus cores. J Virol 1997; 71:7728-35. [PMID: 9311857 PMCID: PMC192124 DOI: 10.1128/jvi.71.10.7728-7735.1997] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
NTPase activities in mammalian reovirus cores were examined under various conditions that permitted several new differences to be identified between strains type 1 Lang (T1L) and type 3 Dearing (T3D). One difference concerned the ratio (at pH 8.5) of ATP hydrolysis at 50 degrees C to that at 35 degrees C. A genetic analysis using T1L x T3D reassortant viruses implicated the L3 and M1 gene segments in this difference, with M1 influencing ATPase activity most strongly at high temperatures. L3 and M1 encode the core proteins lambda1 and mu2, respectively. Another difference concerned the absolute levels of GTP hydrolysis by cores at 45 degrees C and pH 6.5. A genetic analysis using T1L x T3D reassortants implicated the M1 gene as the sole determinant of this difference. The results of these experiments, coupled with previous findings (S. Noble and M. L. Nibert, J. Virol. 71:2182-2191, 1997), suggest either that a single type of NTPase in cores is strongly influenced by two different core proteins--lambda1 and mu2--or that cores contain two different types of NTPase influenced by the two proteins. The findings appear relevant for understanding the complex functions of reovirus cores in RNA synthesis and capping.
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Affiliation(s)
- S Noble
- Institute for Molecular Virology, Graduate School, and Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin-Madison, 52706, USA
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Bisaillon M, Bergeron J, Lemay G. Characterization of the nucleoside triphosphate phosphohydrolase and helicase activities of the reovirus lambda1 protein. J Biol Chem 1997; 272:18298-303. [PMID: 9218469 DOI: 10.1074/jbc.272.29.18298] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Previous studies have shown that the reovirus lambda1 core protein harbors a putative nucleotide-binding motif and exhibits an affinity for nucleic acids. In addition, a nucleoside triphosphate phosphohydrolase activity present in reovirus cores has been recently assigned to lambda1 using gene reassortment analysis. In this study, it was demonstrated that the recombinant lambda1 protein, expressed in the yeast Pichia pastoris, is able to hydrolyze nucleoside 5'-triphosphates or deoxynucleoside 5'-triphosphates. This activity was absolutely dependent on the presence of a divalent cation, Mg2+ or Mn2+. The protein can also unwind double-stranded nucleic acid molecules in the presence of a nucleoside 5'-triphosphate or deoxynucleoside 5'-triphosphate. These results provide the first biochemical evidence that the reovirus lambda1 protein is a nucleoside triphosphate phosphohydrolase/helicase and strongly support the idea that lambda1 participates in transcription of the viral genome.
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Affiliation(s)
- M Bisaillon
- Département de Microbiologie et Immunologie, Université de Montréal, Montréal, Québec H3C 3J7, Canada
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Noble S, Nibert ML. Characterization of an ATPase activity in reovirus cores and its genetic association with core-shell protein lambda1. J Virol 1997; 71:2182-91. [PMID: 9032352 PMCID: PMC191325 DOI: 10.1128/jvi.71.3.2182-2191.1997] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
A previously identified nucleoside triphosphatase activity in mammalian reovirus cores was further characterized by comparing two reovirus strains whose cores differ in their efficiencies of ATP hydrolysis. In assays using a panel of reassortant viruses derived from these strains, the difference in ATPase activity at standard conditions was genetically associated with viral genome segment L3, encoding protein lambda1, a major constituent of the core shell that possesses sequence motifs characteristic of other ATPases. The ATPase activity of cores was affected by several other reaction components, including temperature, pH, nature and concentration of monovalent and divalent cations, and nature and concentration of anions. A strain difference in the response of core ATPase activity to monovalent acetate salts was also mapped to L3/lambda1 by using reassortant viruses. Experiments with different nucleoside triphosphates demonstrated that ATP is the preferred ribonucleotide substrate for cores of both strains. Other experiments suggested that the ATPase is latent in reovirus virions and infectious subviral particles but undergoes activation during production of cores in close association with the protease-mediated degradation of outer-capsid protein mu1 and its cleavage products, suggesting that mu1 may play a role in regulating the ATPase.
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Affiliation(s)
- S Noble
- Department of Biochemistry, University of Wisconsin-Madison, 53706, USA
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Joklik WK, Roner MR. Molecular recognition in the assembly of the segmented reovirus genome. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1996; 53:249-81. [PMID: 8650305 DOI: 10.1016/s0079-6603(08)60147-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- W K Joklik
- Department of Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA
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12
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Gottlieb P, Strassman J, Mindich L. Protein P4 of the bacteriophage phi 6 procapsid has a nucleoside triphosphate-binding site with associated nucleoside triphosphate phosphohydrolase activity. J Virol 1992; 66:6220-2. [PMID: 1326667 PMCID: PMC283676 DOI: 10.1128/jvi.66.10.6220-6222.1992] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Bacteriophage phi 6 contains three segments of double-stranded RNA. The procapsid consists of proteins P1, P2, P4, and P7, which are encoded by the viral L segment. cDNA copies of this segment have been cloned into plasmids that direct the production of these proteins, which assemble into polyhedral procapsids. These procapsids are capable of packaging plus-sense phi 6 RNA in the presence of nucleoside triphosphate and synthesizing the complementary minus strand to form double-stranded RNA. In this article, we report the presence of a nucleotide-binding site in protein P4. The viral procapsid and nucleocapsid exhibit a nucleoside triphosphate phosphohydrolase activity that converts nucleoside triphosphates into nucleoside diphosphates.
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Affiliation(s)
- P Gottlieb
- Department of Microbiology, Public Health Research Institute, New York, New York 10016
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13
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Mao ZX, Joklik WK. Isolation and enzymatic characterization of protein lambda 2, the reovirus guanylyltransferase. Virology 1991; 185:377-86. [PMID: 1656591 DOI: 10.1016/0042-6822(91)90785-a] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Protein lambda 2 of reovirus serotype 3 has been purified to homogeneity from extracts of cells infected with hybrid vaccinia virus strain WR into whose TK gene of the reovirus L2 genome segment under the control of the CPV ATI protein gene promoter had been inserted. Protein lambda 2 is formed in large amounts (final purification factor about 180) as a monomer that shows no tendency to pentamerize into the reovirus core projections/spikes. Isolated protein lambda 2 is reversibly guanylylated by GTP (that is, it carries out the GTP-PPi exchange reaction) and can transfer the -GMP moiety to GTP to form GppppG, to GDP to form GpppG, and to 5'-pp-terminated RNA to form GpppG- caps. These studies confirm previous studies on reovirus cores that indicated that protein lambda 2 is the reovirus guanylyltransferase. Protein lambda 2 possesses neither nucleoside nor RNA triphosphatase activities, nor methyltransferase activities; thus it is the reovirus capping enzyme, but provides neither the required 5'-ppG-terminated substrate nor does it methylate the cap structure. These must be functions of lambda 2 pentamers or of other individual or complexed components of reovirus cores.
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Affiliation(s)
- Z X Mao
- Department of Microbiology and Immunology, Duke University Medical Center, Durham, North Carolina 27710
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14
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Valdeira ML, Duque-Magalhães MC, Geraldes A. Evidence for an acid phosphatase in African swine fever virus. Arch Virol 1990; 113:125-31. [PMID: 2386433 DOI: 10.1007/bf01318361] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
An acid phosphatase activity has been detected in purified preparations of African swine fever virus. Purified viral cores obtained after Nonidet-P40 and 2-mercaptoethanol treatment of the virus retained the activity as assayed with nitrophenyl phosphate as substrate at pH 5. Enzyme cytochemistry by electron microscopy showed that the acid phosphatase activity is localized mainly inside the core of the virion. The molecular weight and the isoelectric point of the virus acid phosphatase activity confirmed that it was distinct from the host cellular enzyme.
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Affiliation(s)
- M L Valdeira
- Faculty of Pharmacy, National Laboratory of Veterinary Research, Lisboa, Portugal
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15
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Mindich L. Bacteriophage phi 6: a unique virus having a lipid-containing membrane and a genome composed of three dsRNA segments. Adv Virus Res 1988; 35:137-76. [PMID: 3068964 DOI: 10.1016/s0065-3527(08)60710-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- L Mindich
- Department of Microbiology, Public Health Research Institute, New York, New York 10016
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16
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Abstract
Recent progress in molecular biological techniques revealed that genomes of animal viruses are complex in structure, for example, with respect to the chemical nature (DNA or RNA), strandedness (double or single), genetic sense (positive or negative), circularity (circle or linear), and so on. In agreement with this complexity in the genome structure, the modes of transcription and replication are various among virus families. The purpose of this article is to review and bring up to date the literature on viral RNA polymerases involved in transcription of animal DNA viruses and in both transcription and replication of RNA viruses. This review shows that the viral RNA polymerases are complex in both structure and function, being composed of multiple subunits and carrying multiple functions. The functions exposed seem to be controlled through structural interconversion.
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Affiliation(s)
- A Ishihama
- Department of Molecular Genetics, National Institute of Genetics, Shizuoka, Japan
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17
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Abstract
Reovirus guanylyltransferase, studied as a covalent enzyme-GMP intermediate, was used to guanylate appropriate acceptor molecules in vitro to produce authentic cap structures. Guanylyltransferase activity was associated with lambda 2, the 140-kilodalton product of the L2 gene segment of reovirus serotypes 1 and 3.
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18
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Ward CW, Elleman TC, Azad AA, Dyall-Smith ML. Nucleotide sequence of gene segment 9 encoding a nonstructural protein of UK bovine rotavirus. Virology 1984; 134:249-53. [PMID: 6324473 DOI: 10.1016/0042-6822(84)90292-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A full-length ds cDNA copy of UK bovine rotavirus gene segment 9, which codes for a nonstructural protein, has been cloned into the PstI site of pBR322, and its sequence has been determined by cloning into bacteriophage M13mp8. Gene 9 is 1076 nucleotides long and contains a single, long, open-reading frame capable of coding for a protein of 313 amino acid residues. The possible function of this nonstructural protein in virus replication is discussed.
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Reeve AE, Shatkin AJ, Huang RC. Guanosine 5'-O-(3-thiotriphosphate) inhibits capping of reovirus mRNA. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)34531-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Yamakawa M, Furuichi Y, Shatkin AJ. Reovirus transcriptase and capping enzymes are active in intact virions. Virology 1982; 118:157-68. [PMID: 7080437 DOI: 10.1016/0042-6822(82)90329-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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22
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Morgan EM, Kingsbury DW. Reovirus enzymes that modify messenger RNA are inhibition by perturbation of the lambda proteins. Virology 1981; 113:565-72. [PMID: 6267798 DOI: 10.1016/0042-6822(81)90184-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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23
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Zarbl H, Hastings KE, Millward S. Reovirus core particles synthesize capped oligonucleotides as a result of abortive transcription. Arch Biochem Biophys 1980; 202:348-60. [PMID: 7458325 DOI: 10.1016/0003-9861(80)90437-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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25
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Abstract
We examined the enzyme activities associated with progeny subviral particles isolated from L-cells infected with reovirus at 12 h postinfection. Activities normally present in reovirus cores were also found to be present in the progeny subviral particles, with the exception of the capping enzymes. The methylase and guanyl transferase activities, which constitute the capping system, were present in a masked form that could be activated by chymotrypsin digestion. The appearance of these progeny subviral particles in infected cells coincided with the time when mRNA synthesis was maximal, suggesting that viral mRNA synthesized at later times is uncapped.
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26
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Srivatsan ES, Baluda MA. Inhibition of virion-associated reverse transcription by nucleoside triphosphatase in avian myeloblastosis virus. J Virol 1980; 34:288-92. [PMID: 6154806 PMCID: PMC288698 DOI: 10.1128/jvi.34.1.288-292.1980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
RNA-dependent DNA polymerase activity of avian myeloblastosis virions as measured by the incorporation of [3H]TTP into trichloroacetic acid-precipitable material was very low. This apparent low polymerase activity was observed with virions isolated either from leukemic chicken plasma or from the supernatant of cultured leukemic myeloblasts. The inhibition of reverse transcriptase activity was caused by nucleoside triphosphatase present in avian myeloblastosis virions and could be reversed by ADP.
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27
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Kortsaris A, Georgatsos JG, Taylor-Papadimitriou J. A cytidine specific endonuclease activity associated with purified reovirus virions. Biochem Biophys Res Commun 1980; 93:57-65. [PMID: 6246901 DOI: 10.1016/s0006-291x(80)80245-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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28
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Koizumi S, Simizu B, Ishida I, Oya A, Yamada M. Inhibition of DNA synthesis in BHK cells infected with western equine encephalitis virus. 2. Properties of the inhibitory factor of DNA polymerase induced in infected cells. Virology 1979; 98:439-47. [PMID: 228480 DOI: 10.1016/0042-6822(79)90566-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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29
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Nakashima K, LaFiandra A, Shatkin A. Differential dependence of reovirus-associated enzyme activities on genome RNA as determined by psoralen photosensitivity. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(18)36044-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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30
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Carter CA. Activation of reovirion-associated poly(A) polymerase and oligomer methylase by cofactor-dependent cleavage of mu polypeptides. Virology 1979; 94:417-29. [PMID: 452422 DOI: 10.1016/0042-6822(79)90472-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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31
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Koizumi S, Simizu B, Hashimoto K, Oya A, Yamada M. Inhibition of DNA synthesis in BHK cells infected with western equine encephalitis virus. 1. Induction of an inhibitory factor of cellular DNA polymerase activity. Virology 1979; 94:314-22. [PMID: 452420 DOI: 10.1016/0042-6822(79)90464-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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32
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33
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Furuichi Y, Shatkin AJ. A simple method for the preparation of [beta-32P]purine nucleoside triphosphase. Nucleic Acids Res 1977; 4:3341-55. [PMID: 928062 PMCID: PMC342657 DOI: 10.1093/nar/4.10.3341] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A rapid, simple and inexpensive procedure is described for the preparation of purine ribo-and deoxyribonucleoside triphosphates specifically and highly radiolabeled with [32P]phosphate in the beta position. The method involves two successive enzymatic reactions: conversion of donor [gamma-32P]ATP in the presence of an excess of acceptor 5'-mononucleotide to the 5'-diphosphates by myokinase or guanosine 5'-monophosphate kinase followed by phosphorylation with pyruvate kinase to yield 5'-triphosphates.
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Gomatos PJ, Kuechenthal I. Reovirus-specific enzyme(s) associated with subviral particles responds in vitro to polyribocytidylate to yield double-stranded polyribocytidylate-polyriboguanylate. J Virol 1977; 23:80-90. [PMID: 886647 PMCID: PMC515802 DOI: 10.1128/jvi.23.1.80-90.1977] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
In reovirus-infected cells, virus-specific particles accumulate that have associated with them a polyribocytidylate [poly(C)]-dependent polymerase. This enzyme copies in vitro poly(C) to yield the double-stranded poly(C).polyriboguanylate [poly(G)]. The particles with poly(C)-dependent polymerase were heterogeneous in size, with most sedimenting from 300S to 550S. Exponential increase in these particles began at 23 h, and maximal amounts were present by 31 h, the time of onset of exponential growth of virus at 30 degrees C. Maximal amounts of particles with active transcriptase and replicase were present at 15 and 18 h after infection. Thereafter, there was a marked decrease in particles with active transcriptase and replicase until base line levels were reached at 31 h. Thus, the increase in poly(C)-responding particles occurred coincident with the decrease in particles with active transcriptase and replicase. The requirement for poly(C) as template was specific because no RNA was synthesized in vitro in response to any other homopolymer, including 2'-O-methyl-poly(C). Synthesis was optimal in the presence of Mn(2+) as the divalent cation, and no primer was necessary for synthesis. In contrast, the dinucleotide GpG markedly stimulated synthesis in the presence of 8 mM Mg(2+). The size of the poly(C).poly(G) synthesized in vitro was dependent on the size of the poly(C) used as template. This suggested that the whole template was copied into a complementary strand of similar size. The T(m) of the product was between 100 and 130 degrees C. Hydrolysis of the product labeled in [(32)P]GMP with alkali or RNase T2 yielded GMP as the only labeled mononucleotide. This does indicate that the synthesis of the poly(G) strand in vitro did not proceed by end addition to the poly(C) template, but proceeded on a separate strand.
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Furuichi Y, Shatkin AJ. 5'-termini of reovirus mRNA: ability of viral cores to form caps post-transcriptionally. Virology 1977; 77:566-78. [PMID: 855185 DOI: 10.1016/0042-6822(77)90482-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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36
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Furuichi Y, Muthukrishnan S, Tomasz J, Shatkin AJ. Caps in eukaryotic mRNAs: mechanism of formation of reovirus mRNA 5'-terminal m7GpppGm-C. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1977; 19:3-20. [PMID: 190643 DOI: 10.1016/s0079-6603(08)60905-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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37
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Furuichi Y, Muthukrishnan S, Tomasz J, Shatkin AJ. Mechanism of formation of reovirus mRNA 5'-terminal blocked and methylated sequence, m7GpppGmpC. J Biol Chem 1976. [DOI: 10.1016/s0021-9258(17)33218-0] [Citation(s) in RCA: 129] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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38
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Monnier C, Devauchelle G. Enzyme activities associated with an invertebrate iridovirus: nucleotide phosphohydrolase activity associated with iridescent virus type 6 (CIV). J Virol 1976; 19:180-6. [PMID: 7681 PMCID: PMC354845 DOI: 10.1128/jvi.19.1.180-186.1976] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A nucleoside triphosphate phosphohydrolase activity is firmly associated with a purified invertebrate iridovirus, iridescent virus type 6. The enzyme activity hydrolyzes all the nucleoside triphosphates, but has a high preference for ATP. The products of the reaction are nucleoside diphosphates. Conditions for nucleoside triphosphate phosphohydrolase activity are described.
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Gauntt CJ, Griffith MM, Sauck JR, Upson RH, Carlson EC. Properties and origins of infectious rhinovirus type 14 particles of different buoyant densities. J Virol 1975; 16:1265-72. [PMID: 171453 PMCID: PMC355726 DOI: 10.1128/jvi.16.5.1265-1272.1975] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Isopycnic centrifugation of rhinovirus type 14 (RV14), purified from infected HeLa or KB cell cultures, into CsCl gradients resolved two bands of infectious virus particles with buoyant density values of 1.409 +/- 0.007 (H virus) and 1.386 +/- 0.004 (L virus) g/ml. Only H virus was detected by incorporation of radiolabeled uridine into viral RNA, and H virus accounted for the majority of infectivity in gradients. H and L virus could not be differentiated by plaque morphology, extent of neutralization by RV14-specific antiserum, or particle size. Electron microscope studies showed that most L-virus particles were associated with an amorphous material. Treatment of L virus with proteolytic enzymes or rebanding L virus in CsCl gradients resulted in recovery of the majority of infectivity as H virus. Virus purified from cell-free fluids from infected HeLa or KB cell cultures banded only as H virus. HeLa cell cultures challenged with purified H virus and harvested at 3 h postinoculation for virus purification yielded only infectious H virus. Both H and L viruses were detected in cell cultures that had been challenged with purified H virus and harvested at 12 h postinoculation. The data suggest that H virus represents progeny virus, whereas L virus represents sequestered infectious virus particles which become associated with an amorphous material and do not enter into viral replicative processes.
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Faust M, Hastings KE, Millward S. m7G5'ppp5'GmptcpUp at the 5' terminus of reovirus messenger RNA. Nucleic Acids Res 1975; 2:1329-43. [PMID: 1178520 PMCID: PMC344385 DOI: 10.1093/nar/2.8.1329] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In the presence of S-adenosyl methionine the 5' terminal guanosine residue of in vitro synthesized reovirus mRNA becomes methylated at the 2'-OH position. In addition, 7-methyl guanylic acid is condensed covalently at the 5' terminus resulting in the formation of a 5' to 5' triphosphate bridge. Analysis of the 5' terminal sequence of methylated reovirus mRNA revealed that it has the structure m7G5'ppp5'GmpCpUp.
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Furuichi Y, Morgan M, Muthukrishnan S, Shatkin AJ. Reovirus messenger RNA contains a methylated, blocked 5'-terminal structure: m-7G(5')ppp(5')G-MpCp-. Proc Natl Acad Sci U S A 1975; 72:362-6. [PMID: 1054511 PMCID: PMC432305 DOI: 10.1073/pnas.72.1.362] [Citation(s) in RCA: 252] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Reovirus mRNA synthesized in vitro by the virus-associated RNA polymerase in the presence of S-adenosylmethionine contains blocked, methylated 5'-termini with the structure, m-7G(5')ppp(5')G-MpCp. The functional significance and possible mechanism of formation of this novel 5'-5' terminal nucleotide linkage are discussed.
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Faust M, Millward S. In vitro methylation of nascent reovirus mRNA by a virion-associated methyl transferase. Nucleic Acids Res 1974; 1:1739-52. [PMID: 4449734 PMCID: PMC343453 DOI: 10.1093/nar/1.12.1739] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Chymotrypsin-derived cores, but not virions, catalyze the transfer of methyl groups from S-adenosyl methionine (SAM) to nascent mRNA synthesized in vitro by the core polymerase. The reaction requires Mg(++), and is dependent on the presence of all 4 ribonucleoside triphosphates (rNTPs). Methylation proceeds optimally at 51 degrees C. All ten species of mRNA become methylated during transcription and it is estimated that one methyl residue is incorporated per RNA chain. Experiments designed to determine the location of the methylated nucleotide clearly demonstrate that methylation occurs exclusively at the 5' ends of nascent mRNA.
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Shimotono K, Miura K. 5'-Terminal structure of messenger RNA transcribed by RNA polymerase of silkworm cytoplasmic polyhedrosis virus containing double-stranded RNA. J Mol Biol 1974; 86:21-30. [PMID: 4605463 DOI: 10.1016/s0022-2836(74)80004-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
MESH Headings
- Adenosine Triphosphate/metabolism
- Animals
- Aspergillus/enzymology
- Base Sequence
- Bombyx
- Centrifugation, Density Gradient
- Chromatography
- Chromatography, DEAE-Cellulose
- Chromatography, Gel
- DNA-Directed RNA Polymerases/metabolism
- Electrophoresis, Paper
- Insect Viruses/analysis
- Insect Viruses/metabolism
- Nucleotides/analysis
- Pancreas/enzymology
- Phosphorus Radioisotopes
- RNA, Messenger/analysis
- RNA, Messenger/biosynthesis
- RNA, Viral/analysis
- RNA, Viral/biosynthesis
- Ribonucleases
- Templates, Genetic
- Transcription, Genetic
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Abstract
An enzymatic activity which synthesized oligo(A) in vitro was found in highly purified reovirus. The poly(A) polymerase activity was dependent on Mn(2+) and utilized only ATP, whereas the virion-associated RNA polymerase required all four ribonucleoside triphosphates and Mg(2+). Oligo(A) synthesis was demonstrated with complete virions and infectious subviral particles derived from virus by limited chymotrypsin digestion but not with cores, a product of extensive chymotrypsin digestion of virus. The enzymatic product and the oligo(A) from purified virions were isolated by binding to oligo(dT)-cellulose columns. Most of the in vitro product was similar in size and structure to the oligo(A) from purified virions by the criteria of gel electrophoresis, DEAE-cellulose chromatography, end-group analysis, and sensitivity to RNase. The evidence suggests that oligo(A) synthesis is mediated by the poly(A) polymerase during a late step in viral morphogenesis and may result from an alternative activity of the virion-associated transcriptase.
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Silverstein SC, Astell C, Christman J, Klett H, Acs G. Shythesis of reovirus oligo adenylic acid in vivo and in vitro. J Virol 1974; 13:740-52. [PMID: 4856707 PMCID: PMC355361 DOI: 10.1128/jvi.13.3.740-752.1974] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The formation of reovirus double-stranded (ds) RNA and of oligo adenylic acid (oligo A) is inhibited by 5 mug of actinomycin D per ml added at the time of viral infection. Viral proteins are synthesized and assembled into dsRNA-deficient particles under these conditions. The addition of cycloheximide to infected cells during the mid-logarithmic phase of viral replication terminates protein and dsRNA synthesis, but allows continued oligo A synthesis for about 1 h. The (3)H-labeled oligo A formed in the presence of cycloheximide is incorporated into particles whose density in CsCl is identical to that of reovirions. Using the large particulate or virus factory-containing cytoplasmic fraction of infected L-cells, we have established an in vitro system for the synthesis of oligo A. The in vitro product migrates slightly faster in sodium dodecyl sulfate acrylamide gels than marker oligo A. Oligo A synthesis in vitro continues for about 1 h, requires, the presence of only one ribonucleoside triphosphate (ATP), is not inhibited by DNase or RNase, but is abruptly terminated by the addition of chymotrypsin to the reaction mixture. Oligo A formed both in vivo and in vitro is released from the factory fraction by chymotrypsin digestion. The enzymes which catalyze the synthesis of oligo A, dsRNA, and single-stranded RNA all exhibit a similar temperature dependence with an optimum of approximately 45 C. These results indicate that oligo A is formed within the core of the nascent virion after the completion of dsRNA synthesis; they suggest that the oligo A polymerase is an alternative activity of the virion-bound transcriptase and that it is regulated by outer capsomere proteins.
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Banerjee AK, Stolzfus CM, Ward RL, Shatkin AJ. Transcription of reovirus RNA. BASIC LIFE SCIENCES 1974; 3:181-200. [PMID: 4856694 DOI: 10.1007/978-1-4613-4529-9_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
MESH Headings
- Animals
- Base Sequence
- Centrifugation, Density Gradient
- Chromatography, DEAE-Cellulose
- Chymotrypsin/pharmacology
- DNA-Directed RNA Polymerases/metabolism
- Electrophoresis, Polyacrylamide Gel
- L Cells
- Mice
- Microscopy, Electron
- Molecular Weight
- Oligonucleotides/analysis
- Phosphorus Radioisotopes
- RNA, Messenger/analysis
- RNA, Messenger/biosynthesis
- RNA, Viral/analysis
- RNA, Viral/biosynthesis
- RNA, Viral/metabolism
- Reoviridae/enzymology
- Reoviridae/metabolism
- Ribonucleases/metabolism
- Ribonucleotides/metabolism
- Transcription, Genetic
- Tritium
- Viral Proteins/analysis
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Warrington RC, Hayward C, Kapuler AM. Conformational studies of reovirus single-stranded RNAs synethesized in vitro. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 331:231-42. [PMID: 4798025 DOI: 10.1016/0005-2787(73)90436-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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50
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Abstract
Compared with several other enveloped viruses, purified virions of frog virus 3 contained a relatively high activity of a protein kinase which catalyzed the phosphorylation of endogenous polypeptides or added substrate proteins. Virions also contained a phosphoprotein phosphatase activity which released phosphate covalently linked to proteins. It was possible to select reaction conditions where turnover of protein phosphoesters was minimal, as the phosphatase required Mn(2+) ions for activity whereas the protein kinase was active in the presence of Mg(2+) ions. Electrophoretic studies in polyacrylamide gels containing sodium dodecyl sulfate indicated that at least 10 of the virion polypeptides were phosphorylated in the in vitro protein kinase reaction. Characterization of these phosphoproteins demonstrated that the phosphate was incorporated predominantly in a phosphoester linkage with serine residues. The protein kinase was solubilized by disrupting purified virions with a nonionic detergent in a high-ionic-strength buffer and was separated from many of the virion substrate proteins by zonal centrifugation in glycerol gradients. The partially purified protein kinase would phosphorylate polypeptides of many different animal viruses, and maximal activity was not dependent on added cyclic nucleotides. These properties distinguished the virion protein kinase from a well characterized cyclic AMP-dependent protein kinase which phosphorylated viral proteins only to a small extent.
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