1
|
Thoner TW, Meloy MM, Long JM, Diller JR, Slaughter JC, Ogden KM. Reovirus Efficiently Reassorts Genome Segments during Coinfection and Superinfection. J Virol 2022; 96:e0091022. [PMID: 36094315 PMCID: PMC9517712 DOI: 10.1128/jvi.00910-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 08/21/2022] [Indexed: 11/20/2022] Open
Abstract
Reassortment, or genome segment exchange, increases diversity among viruses with segmented genomes. Previous studies on the limitations of reassortment have largely focused on parental incompatibilities that restrict generation of viable progeny. However, less is known about whether factors intrinsic to virus replication influence reassortment. Mammalian orthoreovirus (reovirus) encapsidates a segmented, double-stranded RNA (dsRNA) genome, replicates within cytoplasmic factories, and is susceptible to host antiviral responses. We sought to elucidate the influence of infection multiplicity, timing, and compartmentalized replication on reovirus reassortment in the absence of parental incompatibilities. We used an established post-PCR genotyping method to quantify reassortment frequency between wild-type and genetically barcoded type 3 reoviruses. Consistent with published findings, we found that reassortment increased with infection multiplicity until reaching a peak of efficient genome segment exchange during simultaneous coinfection. However, reassortment frequency exhibited a substantial decease with increasing time to superinfection, which strongly correlated with viral transcript abundance. We hypothesized that physical sequestration of viral transcripts within distinct virus factories or superinfection exclusion also could influence reassortment frequency during superinfection. Imaging revealed that transcripts from both wild-type and barcoded viruses frequently co-occupied factories, with superinfection time delays up to 16 h. Additionally, primary infection progressively dampened superinfecting virus transcript levels with greater time delay to superinfection. Thus, in the absence of parental incompatibilities and with short times to superinfection, reovirus reassortment proceeds efficiently and is largely unaffected by compartmentalization of replication and superinfection exclusion. However, reassortment may be limited by superinfection exclusion with greater time delays to superinfection. IMPORTANCE Reassortment, or genome segment exchange between viruses, can generate novel virus genotypes and pandemic virus strains. For viruses to reassort their genome segments, they must replicate within the same physical space by coinfecting the same host cell. Even after entry into the host cell, many viruses with segmented genomes synthesize new virus transcripts and assemble and package their genomes within cytoplasmic replication compartments. Additionally, some viruses can interfere with subsequent infection of the same host or cell. However, spatial and temporal influences on reassortment are only beginning to be explored. We found that infection multiplicity and transcript abundance are important drivers of reassortment during coinfection and superinfection, respectively, for reovirus, which has a segmented, double-stranded RNA genome. We also provide evidence that compartmentalization of transcription and packaging is unlikely to influence reassortment, but the length of time between primary and subsequent reovirus infection can alter reassortment frequency.
Collapse
Affiliation(s)
- Timothy W. Thoner
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Madeline M. Meloy
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jacob M. Long
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Julia R. Diller
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - James C. Slaughter
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kristen M. Ogden
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| |
Collapse
|
2
|
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.
Collapse
|
3
|
Abad AT, Danthi P. Recognition of Reovirus RNAs by the Innate Immune System. Viruses 2020; 12:E667. [PMID: 32575691 PMCID: PMC7354570 DOI: 10.3390/v12060667] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 06/05/2020] [Accepted: 06/18/2020] [Indexed: 12/15/2022] Open
Abstract
Mammalian orthoreovirus (reovirus) is a dsRNA virus, which has long been used as a model system to study host-virus interactions. One of the earliest interactions during virus infection is the detection of the viral genomic material, and the consequent induction of an interferon (IFN) based antiviral response. Similar to the replication of related dsRNA viruses, the genomic material of reovirus is thought to remain protected by viral structural proteins throughout infection. Thus, how innate immune sensor proteins gain access to the viral genomic material, is incompletely understood. This review summarizes currently known information about the innate immune recognition of the reovirus genomic material. Using this information, we propose hypotheses about host detection of reovirus.
Collapse
Affiliation(s)
| | - Pranav Danthi
- Department of Biology, Indiana University, Bloomington, IN 47405, USA;
| |
Collapse
|
4
|
Zhang X, Ma X, Jing S, Zhang H, Zhang Y. Non-coding RNAs and retroviruses. Retrovirology 2018; 15:20. [PMID: 29426337 PMCID: PMC5807749 DOI: 10.1186/s12977-018-0403-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/31/2018] [Indexed: 02/06/2023] Open
Abstract
Retroviruses can cause severe diseases such as cancer and acquired immunodeficiency syndrome. A unique feature in the life cycle of retroviruses is that their RNA genome is reverse transcribed into double-stranded DNA, which then integrates into the host genome to exploit the host machinery for their benefits. The metazoan genome encodes numerous non-coding RNAs (ncRNA), which act as key regulators in essential cellular processes such as antiviral response. The development of next-generation sequencing technology has greatly accelerated the detection of ncRNAs from viruses and their hosts. ncRNAs have been shown to play important roles in the retroviral life cycle and virus–host interactions. Here, we review recent advances in ncRNA studies with special focus on those have changed our understanding of retroviruses or provided novel strategies to treat retrovirus-related diseases. Many ncRNAs such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are involved in the late phase of the retroviral life cycle. However, their roles in the early phase of viral replication merit further investigations.
Collapse
Affiliation(s)
- Xu Zhang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Xiancai Ma
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Shuliang Jing
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Hui Zhang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China. .,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China. .,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.
| | - Yijun Zhang
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, 06520, USA.
| |
Collapse
|
5
|
Fry M. Dissolution of hypotheses in biochemistry: three case studies. HISTORY AND PHILOSOPHY OF THE LIFE SCIENCES 2016; 38:17. [PMID: 27813029 DOI: 10.1007/s40656-016-0118-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 10/26/2016] [Indexed: 06/06/2023]
Abstract
The history of biochemistry and molecular biology is replete with examples of erroneous theories that persisted for considerable lengths of time before they were rejected. This paper examines patterns of dissolution of three such erroneous hypotheses: The idea that nucleic acids are tetrads of the four nucleobases ('the tetranucleotide hypothesis'); the notion that proteins are collinear with their encoding genes in all branches of life; and the hypothesis that proteins are synthesized by reverse action of proteolytic enzymes. Analysis of these cases indicates that amassed contradictory empirical findings did not prompt critical experimental testing of the prevailing theories nor did they elicit alternative hypotheses. Rather, the incorrect models collapsed when experiments that were not purposely designed to test their validity exposed new facts.
Collapse
Affiliation(s)
- Michael Fry
- Department of Biochemistry, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, POB 9649, 31096, Haifa, Israel.
| |
Collapse
|
6
|
FURUICHI Y. Discovery of m(7)G-cap in eukaryotic mRNAs. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2015; 91:394-409. [PMID: 26460318 PMCID: PMC4729855 DOI: 10.2183/pjab.91.394] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Terminal structure analysis of an insect cytoplasmic polyhedrosis virus (CPV) genome RNA in the early 1970s at the National Institute of Genetics in Japan yielded a 2'-O-methylated nucleotide in the 5' end of double-stranded RNA genome. This finding prompted me to add S-adenosyl-L-methionine, a natural methylation donor, to the in vitro transcription reaction of viruses that contain RNA polymerase. This effort resulted in unprecedented mRNA synthesis that generates a unique blocked and methylated 5' terminal structure (referred later to as "cap" or "m(7)G-cap") in the transcription of silkworm CPV and human reovirus and vaccinia viruses that contain RNA polymerase in virus particles. Initial studies with viruses paved the way to discover the 5'-cap m(7)GpppNm structure present generally in cellular mRNAs of eukaryotes. I participated in those studies and was able to explain the pathway of cap synthesis and the significance of the 5' cap (and capping) in gene expression processes, including transcription and protein synthesis. In this review article I concentrate on the description of these initial studies that eventually led us to a new paradigm of mRNA capping.
Collapse
Affiliation(s)
- Yasuhiro FURUICHI
- GeneCare Research Institute Co., Ltd., Kanagawa, Japan
- Correspondence should be addressed: Y. Furuichi, GeneCare Research Institute Co., Ltd., 19-2 Kajiwara, Kamakura, Kanagawa 247-0063, Japan (e-mail: )
| |
Collapse
|
7
|
Fujimoto M, Kuninaka A, Yoshino H. Some Physical and Chemical Properties of Nuclease P1. ACTA ACUST UNITED AC 2014. [DOI: 10.1080/00021369.1975.10861894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
8
|
Abstract
This chapter focuses on the history of the discovery of cap and an update of research on viral and cellular-messenger RNA (mRNA) capping. Cap structures of the type m7 GpppN(m)pN(m)p are present at the 5′ ends of nearly all eukaryotic cellular and viral mRNAs. A cap is added to cellular mRNA precursors and to the transcripts of viruses that replicate in the nucleus during the initial phases of transcription and before other processing events, including internal N6A methylation, 3′-poly (A) addition, and exon splicing. Despite the variations on the methylation theme, the important biological consequences of a cap structure appear to correlate with the N7-methyl on the 5′-terminal G and the two pyrophosphoryl bonds that connect m7G in a 5′–5′ configuration to the first nucleotide of mRNA. In addition to elucidating the biochemical mechanisms of capping and the downstream effects of this 5′- modification on gene expression, the advent of gene cloning has made available an ever-increasing amount of information on the proteins responsible for producing caps and the functional effects of other cap-related interactions. Genetic approaches have demonstrated the lethal consequences of cap failure in yeasts, and complementation studies have shown the evolutionary functional conservation of capping from unicellular to metazoan organisms.
Collapse
Affiliation(s)
- Y Furuichi
- AGENE Research Institute, Kamakura, Japan
| | | |
Collapse
|
9
|
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
| | | |
Collapse
|
10
|
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.
Collapse
Affiliation(s)
- A Ishihama
- Department of Molecular Genetics, National Institute of Genetics, Shizuoka, Japan
| | | |
Collapse
|
11
|
|
12
|
Imai M, Akatani K, Ikegami N, Furuichi Y. Capped and conserved terminal structures in human rotavirus genome double-stranded RNA segments. J Virol 1983; 47:125-36. [PMID: 6306269 PMCID: PMC255212 DOI: 10.1128/jvi.47.1.125-136.1983] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Both 3'- and 5'-terminal structures of human rotavirus genome double-stranded RNA segments were determined. RNAs were labeled at the 3'-termini with [32P]pCp by incubation with RNA ligase and at the 5'-termini with [32P]phosphate by polynucleotide kinase or, in the case of 5' caps, with 3H by chemical modification with [3H]NaBH4. Examination of radiolabeled termini released by digestion with several base-specific RNases revealed that rotavirus RNA segments are base paired end-to-end and contain the same terminal structures: (formula; see text)
Collapse
|
13
|
Iba H, Watanabe T, Emori Y, Okada Y. Three double-stranded RNA genome segments of bacteriophage phi 6 have homologous terminal sequences. FEBS Lett 1982; 141:111-5. [PMID: 7084474 DOI: 10.1016/0014-5793(82)80027-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
14
|
Smith RE, Morgan MA, Furuichi Y. Separation of the plus and minus strands of cytoplasmic polyhedrosis virus and human reovirus double-stranded genome RNAs by gel electrophoresis. Nucleic Acids Res 1981; 9:5269-86. [PMID: 7029468 PMCID: PMC327519 DOI: 10.1093/nar/9.20.5269] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The complementary strands of most of the genome double-stranded RNA segments of insect cytoplasmic polyhedrosis virus (CPV) and human reovirus are separated for the first time by agarose gel electrophoresis in in the presence of 7 M urea. CPV (+) strands and most reovirus (-) strands migrate faster than the corresponding strands of opposite polarity. Glyoxal treatment, which modifies guanine residues and prevents G-C basepairing, results in a loss of strand resolution and concomitantly a significant decrease in electrophoretic mobilities. Reovirus mRNAs synthesized in vitro with ITP substituted for GTP show similar decreased electrophoretic mobilities as the glyoxalated mRNAs. These results clearly indicate that the basis for (+) and (-) strand resolution is the presence of secondary structure formed mainly by G-C(U) base-pairs that are maintained during gel electrophoresis in the presence of 7 M urea. When the plus and minus strands of CPV genomes were separated and compared for protein synthesizing activity, it was found that only the plus strands were able to form stable 80S ribosome-RNA initiation complexes in wheat germ cell-free extracts.
Collapse
|
15
|
|
16
|
|
17
|
Darzynkiewicz E, Shatkin AJ. Assignment of reovirus mRNA ribosome binding sites to virion genome segments by nucleotide sequence analyses. Nucleic Acids Res 1980; 8:337-50. [PMID: 7422544 PMCID: PMC327270 DOI: 10.1093/nar/8.2.337] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
All ten reovirus genome RNA segments were radiolabeled at their 3'-termini by incubation with RNA ligase and 32pCp. The extent of radiolabeling was similar for each of the double-stranded RNAs in the genome segment mixture. Radioactivity was equally distributed between the separated plus and minus strands indicating that the 5'-cap in plus strands did not block 3'-end-labeling of minus strands. The 3'-termini of the four S and three M segments included the common sequences: ...U-A-G-C in minus strands and ...U-C-A-U-C in plus strands. By comparing the minus strand 3'-sequences with 5'-sequences of reovirus mRNAs, small-size genome segments S2, S3 and S4 were correlated with the previously sequenced initiation fragments s46, s45 and s54 derived from small class mRNAs. Medium-size genome segments M1, M2 and M3 similarly were correlated with fragments m30, m52 and m44, respectively. The N-terminal amino acid sequences deduced from the mRNA nucleotide sequences can now be assigned to the nascent chains of particular reovirus proteins.
Collapse
|
18
|
Nakashima K, Shatkin A. Photochemical cross-linking of reovirus genome RNA in situ and inactivation of viral transcriptase. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34228-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
19
|
Moss B, Keith JM, Gershowitz A, Ritchey MB, Palese P. Common sequence at the 5' ends of the segmented RNA genomes of influenza A and B viruses. J Virol 1978; 25:312-8. [PMID: 621778 PMCID: PMC353928 DOI: 10.1128/jvi.25.1.312-318.1978] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Guanylyl- and methyltransferases, isolated from purified vaccinia virus, were used to specifically label the 5' ends of the genome RNAs of influenza A and B viruses. All eight segments were labeled with [alpha-(32)P]guanosine 5'-triphosphate or S-adenosyl[methyl-(3)H]methionine to form "cap" structures of the type m(7)G(5')pppN(m)-, of which unmethylated (p)ppN- represents the original 5' end. Further analyses indicated that m(7)G(5')pppA(m), m(7)G(5')pppA(m)pGp, and m(7)G(5')pppA(m)pGpUp were released from total and individual labeled RNA segments by digestion with nuclease P1, RNase T1, and RNase A, respectively. Consequently, the 5'-terminal sequences of most or all individual genome RNAs of influenza A and B viruses were deduced to be (p)ppApGpUp. The presence of identical sequences at the ends of RNA segments of both types of influenza viruses indicates that they have been specifically conserved during evolution.
Collapse
|
20
|
|
21
|
Abstract
La Crosse (LAC) virions purified by velocity and equilibrium gradient centrifugation contained three single-stranded RNA species. The three segments had sedimentation coefficients of 31S, 25S, and 12S by sodium dodecyl sulfate-sucrose gradient centrifugation. By comparison with other viral and cellular RNA species, the LAC viral RNAs had molecular weights of 2.9 x 10(6), 1.8 x 10(6), and 0.4 x 10(6). Phenol-sodium dodecyl sulfate-extracted LAC virion RNA was not infectious for BHK-21 cell cultures under conditions in which Sindbis viral RNA was infectious. Treatment of LAC virus with the nonionic detergent Triton X-100 and salt released three nucleocapsid structures, each containing one species of virion RNA. The nucleocapsids had sedimenation coefficients of 115S, 90S, and 65S. Negative-contrast electron microscopy of the nucleocapsids indicated that they were convoluted, supercoiled, and apparently circular. They had a mean diameter of 10 to 12 nm and modal lengths of 200, 510, and 700 nm (some were even longer). By chemical and enzymatic analysis of purified viral RNA, one type of 5' nucleotide (pppAp) present in the proportion of one per RNA segment was identified. After periodate oxidation, each virion RNA species was labeled by reduction with [3H]sodium borohydride. Taken together, these results suggest that although the nucleocapsids appear as closed loops, the viral RNA has free 5' and 3' ends and is, therefore, not circular.
Collapse
|
22
|
Singh H, Herbut MH, Ilo R, Lee CH, Sarma RH. Conformational features of 2'-O-methyl-adenosylyl-adenosine. Biopolymers 1976; 15:2167-84. [PMID: 990401 DOI: 10.1002/bip.1976.360151106] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
23
|
Buck KW. Replication of double-stranded RNA in particles of Penicillium stoloniferum virus S. Nucleic Acids Res 1975; 2:1889-902. [PMID: 1187348 PMCID: PMC343554 DOI: 10.1093/nar/2.10.1889] [Citation(s) in RCA: 36] [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
RNA polymerase activity was assayed in different particle classes of Penicillium stoloniferum virus S. RNA polymerase activity was found to be associated with H particles, which contain double-stranded RNA and single-stranded RNA, but not with L particles, which contain only double-stranded RNA and not with M particles, which contain only single-stranded RNA. In H particles the reaction occurred with the formation of one new molecule of double-stranded RNA (or two complementary single strands of RNA) per virus particle and the production of product particles (P particles), which contained two molecules of double-stranded RNA (or its equivalent). This RNA polymerase is therefore a replicase, which catalyses the synthesis of the two complementary strands of double-stranded RNA in a single virus particle. This is the first report of this type of RNA polymerase system.
Collapse
|
24
|
Colonno RJ, Stone HO. Methylation of messenger RNA of Newcastle disease virus in vitro by a virion-associated enzyme. Proc Natl Acad Sci U S A 1975; 72:2611-5. [PMID: 1058477 PMCID: PMC432819 DOI: 10.1073/pnas.72.7.2611] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Purified Newcastle disease virus contains an enzyme that incorporates the methyl group from S-adenosyl-L-methionine into RNA synthesized in vitro by the virion-associated RNA polymerase (RNA nucleotidyltransferase). Incorporation of radioactivity from S-adenosyl-L-[methyl-3H]methionine was totally dependent upon RNA synthesis. The methylation reaction was completely inhibited by S-adenosyl-L-homocysteine, suggesting the transfer of only the methyl group of S-adenosyl-methionine to RNA products. Velocity sedimentation and hybridization of the in vitro product RNA indicated that both [3H]methyl and [32P]GMP labels resided in single-stranded 18S RNA molecules which were virus specific. Approximately 1 to 2 methyl groups were incorporated per RNA molecule. DEAE-cellulose chromatography of product RNA after alkaline hydrolysis suggested that the 5' terminus was the site of methylation.
Collapse
|
25
|
Abstract
Uniformly
32
P-labeled, double-stranded genome RNA isolated from purified reovirus contains two types of 5′-terminal sequences. One strand contains a phosphatase-resistant 5′-terminal structure, XpppG
*
pCpU, which is also present in the viral mRNA. The 5′ blocking group, X, is removed by β-elimination indicating that it is a nucleoside containing free 2′,3′-hydroxyls. G
*
pC is an alkaline-resistant, 2′-
O
-methylated sequence. The other strand contains a phosphatase-sensitive 5′ sequence, ppGpPupPyp. The results are discussed in relation to blocked 5′-terminal structures in other viral and cellular RNAs.
Collapse
Affiliation(s)
- N L Chow
- Department of Cell Biology, Roche Institute of Molecular Biology, Nutley, New Jersey 07110
| | | |
Collapse
|
26
|
Muthukrishnan S, Both GW, Furuichi Y, Shatkin AJ. 5'-Terminal 7-methylguanosine in eukaryotic mRNA is required for translation. Nature 1975; 255:33-7. [PMID: 165427 DOI: 10.1038/255033a0] [Citation(s) in RCA: 332] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Unmethylated reovirus and VSV mRNAs are specifically methylated to form 5'-terminal structures of the type, m-7-G(5')ppp(5')N by protein synthesising extracts prepared from wheat germ and mouse L cells. Reticulocyte mRNA also contains 5'-terminal m-7-G. MRNAs having 5'-terminal m-7-G stimulate protein synthesis in vitro. Removal of m-7-G by beta-elimination abolishes translation of the mRNAs.
Collapse
|
27
|
Furuichi Y, Muthukrishnan S, Shatkin AJ. 5'-Terminal m-7G(5')ppp(5')G-m-p in vivo: identification in reovirus genome RNA. Proc Natl Acad Sci U S A 1975; 72:742-5. [PMID: 1054852 PMCID: PMC432392 DOI: 10.1073/pnas.72.2.742] [Citation(s) in RCA: 118] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Methylated reovirus mRNA was synthesized in vitro in the presence of S-adenosyl-L-[methyl-3H]-methionine. Viral genome double-stranded RNA that was uniformly labeled with 32-P was isolated from purified virions. The RNAs were mixed and their 5'-terminal structures compared by electrophoretic and chromatographic analyses after enzymatic digestion. Both the mRNA and the corresponding strand in the genome RNA contain m-7G(5')ppp(5')G-m-pCp, indicating that infected cells synthesize viral RNA with blocked, methylated 5' termini.
Collapse
|
28
|
Furuichi Y, Miura K. A blocked structure at the 5' terminus of mRNA from cytoplasmic polyhedrosis virus. Nature 1975; 253:374-5. [PMID: 163011 DOI: 10.1038/253374a0] [Citation(s) in RCA: 210] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
29
|
Abstract
The 5' sequence of Sindbis viral RNA is m (7)G(5') pppApUpGp...
Collapse
|
30
|
Wei CM, Moss B. Methylated nucleotides block 5'-terminus of vaccinia virus messenger RNA. Proc Natl Acad Sci U S A 1975; 72:318-22. [PMID: 164018 PMCID: PMC432296 DOI: 10.1073/pnas.72.1.318] [Citation(s) in RCA: 234] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Studies on the nature and location of the methylated nucleotides in mRNA synthesized in vitro by vaccinia virus particles revealed an unusual 5'-terminal structure. Evidence that the pyrophosphate group is blocked by 7-methylguanosine and that both 2'-O-methyl-adenosine and 2'-O-methylguanosine occupy penultimate positions was presented. According to this model, the 5'-termini of vaccinia virus mRNAs are: 7MeG-5'ppp-5'GMepNp and 7MeG-5'AMepNp.
Collapse
|
31
|
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.
Collapse
|