Virus-Specific Messenger RNA and Nascent Polypeptides in Polyribosomes of Cells Replicating Murine Sarcoma-Leukemia Viruses

Vecchio, Giancarlo; Tsuchida, Nobuo; Shanmugam, G.; Green, M

doi:10.1073/pnas.70.7.2064

Cited by 21 publications

(8 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4) ribosomes. There is no evidence at this time that the genome components of the oncornaviruses are translated immediately after infection, but it is clear that RNA equivalent in structure to the genome appears in the polyribosomes during the later stages of the infection process (23)(24)(25). Furthermore, the RNA subunits of the viral genome certainly are capable of being translated, at least in vitro (26), and they do contain polyadenylate sequences at their 3' termini (27).…”

Section: Resultsmentioning

confidence: 99%

The 7S RNA Common to Oncornaviruses and Normal Cells is Associated with Polyribosomes

Walker¹,

Pace²,

Erikson

et al. 1974

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The 7S RNA species first demonstrated in avian and murine oncornaviruses and later in normal, uninfected cells is' found associated in part with cellular polyribosomes. A molar ratio of 7S RNA to 5S ribosomal RNA of 0.05 indicates that there is approximately one mole of 7S RNA per mole'of messenger RNA. Dissociation of polyribosomes with dimethylsulfoxide results in a marked decrease in the sedimentation rate of the 7 S RNA.The dimethylsiilfoxide-induced dissociation of polyribosomes and the concomitant movement of the 7S RNA from the polyribosome region into lighter regions of a sucrose gradient are both inhibited by cycloheximide, indicating that the 7S RNA is indeed associated with polyribosomes and not with a ribonucleoprotein particle sedimenting with polyribosomes.The avian oncornaviruses contain a variety of RNA components, including the 65S. genome complex (1) and discrete populations of low-molecular-weight species designated 4 S (2), 5 S (3), and 7 S (4). The virion 4S RNA is structurally (3, 5, 6) and functionally (2, 7) similar to that of the host, and the 5S RNA apparently is identical in hucleotide sequence to the host 5S ribosomal RNA (3). The function of these small RNA species remains enigmatic.The viral 7S RNA, first described from oncornaviruses by

show abstract

Section: Resultsmentioning

confidence: 99%

The 7S RNA Common to Oncornaviruses and Normal Cells is Associated with Polyribosomes

Walker¹,

Pace²,

Erikson

et al. 1974

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…It may remain intracellular and carry out no activities, other than a passive one, as a template of protein synthesis. The 35S (paraprocessed) form of tumor virus RNA does become associated with polyribosome-like structures in cells (51). Alternatively, it may become an intracellular self-replicating unit if the cell also contains reverse transcriptase.…”

Section: Paraprocessing Of Class 1 Virus Genomesmentioning

confidence: 99%

RNA Processing and RNA Tumor Virus Origin and Evolution

Gillespie

Gallo

1975

Science

View full text Add to dashboard Cite

The results of molecular hybridization experiments with high-molecular-weight RNA isolated from RNA tumor viruses and DNA from normal cells suggest that RNA tumor virus genomes originate from cell genes. Some RNA tumor viruses (here called class 1) appear to have been generated in recent times in that their RNA is closely related in nucleotide sequence to certain cell genes (class 1 genes). A second class of RNA tumor viruses (here called class 2) is more distantly related to genomic information of normal cells. Structural properties of the RNA of RNA tumor viruses lead us to propose that the tumor virus RNA is originated when RNA transcripts of class 1 genes are processed by a mechanism we call "paraprocessing." We postulate that RNA paraprocessing is normally used only at particular times during differentiation and is characterized by the cytoplasmic appearance of high-molecular-weight RNA chains containing terminal polyadenylic acid (200 residues). Paraprocessing of class 1 gene transcripts in committed or differentiated cells is considered to be aberrant in transcription that can lead to the generation of an RNA tumor virus genome. If the paraprocessed class 1 gene transcript codes for a reverse transcriptase, replication of the RNA becomes possible. Transfer of the replicating RNA to a new cell can result in genetic change such that the virus genome mutates, differing from the original progenitor genes. We propose that this genetic change causes class 1 viruses to become class 2. These ideas are applied to evidence concerning the biology of infection of RNA tumor viruses and concerning the involvement of RNA tumor viruses in human cancer. Genetic change can also occur during the origination of an RNA tumor virus genome by repeated reverse transcription and recombination (45) or by genetic alteration of particularly changeable cell genes ("hot spots") (43).

show abstract

“…Parental viral RNA is found in the polyribosomes in an EDTA-releasable form early after infection of mouse cells with MSV(MLV) (Robin, Salzberg, and Green, in manuscript), but its role as mRNA has not been established. Viral RNA of the same size and sequence content as MSV(MLV) 30-40S RNA subunits are found in free and membranebound polyribosomes of MSV(MLV)-producing rat cells (32,36,37) that synthesize viral polypeptides.…”

Section: Identification Of the 3'-terminal Nucleosides Of Jisv(jilv)mentioning

confidence: 99%

The Homopolyadenylate and Adjacent Nucleotides at the 3′-Terminus of 30-40S RNA Subunits in the Genome of Murine Sarcoma-Leukemia Virus

Rho

Green

1974

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Adenosine is the major 3'OH-terminal nucleoside of the 60-70S RNA genome of the murine sarcoma-leukemia virus, its 30-40S RNA subunits, and the poly(A) segments derived by RNase treatment of both RNA species, as determined by periodate oxidation--[H-_ borohydride reduction. The binding of 30-40S RNA to oligo(dT)-cellulose suggests that most viral RNA subunits contain poly(A). The molecular weight of poly(A) derived from viral RNA by digestion with RNase and purified by affinity chromatography is 64,000-8,000, as determined by gel electrophoresis. From the size of poly(A) and the poly-(A) content of viral RNA (1.6%), it is estimated that there is about one poly(A) segment for each viral 3040S RNA subunit. The results of 3'-termini labeling with ['Hlborohydride, in Purification of Virus and Viral RNA. The MSV-transformed rat-cell line, 78A1, which produces the Moloney strain of MSV(MLV), was grown in suspension culture in Eagle's minimal essential medium supplemented with 10% fetal-calf serum (6). Virus was purified from culture medium collected at 1, 3, or 12 hr after complete renewal of medium (6, 23). Purified virus in NTE buffer (0.1 M NaCl-10 mM TrisHCl-1 mM EDTA, pH 7.4) was lysed by addition of onetenth volume each of 10% dithiothreitol, 5% Na dodecyl sarcosinate, and phenol-chloroform (1:1) (23). The mixture was extracted three times with phenol-chloroform. Viral 60-70S RNA was isolated by zonal centrifugation in a 10-30% sucrose gradient in NTE buffer containing 0.5% Na dodecyl sarcosinate for 2.5 hr at 40,000 rpm in a Spinco SW41 rotor at 40 (Fig. 1A). For isolation of 30-40S RNA, virion 60-70S RNA was heated in NTE buffer at 7Q0 for 3 mmin and centrifuged as described above for 5 hr (Fig. 1B).'H-Labeling of the 3'-Termini of 60-70S and 30-40S RNA. Viral 60-70S RNA (150 ug) and 30-40S RNA (25 Mg) were oxidized with NaIO4 and reduced with KB'H4 to label the 2',3'-terminal glycol group of RNA (20,24). Labeled RNA (200 ;Ml) was purified on a Sephadex G-25 column (2.5 X 30-cm) and by three ethanol precipitations.Chromatography of RNase Digests on DEAE-Sephadex. Terminally labeled 60-70S RNA (50 Mg) or 30-408 RNA (10 Mg) was treated with RNase T1 (10 units/ml) plus RNase A (2 Mg/ml) in 10 mM Tris HCl (pH 7.4)-i mM EDTA-0.3 M NaCl for 1 hr at 37°. The digest (0.2 ml) was mixed with 1.8 ml of 0.3 M NaCl-5 mM TrisKECl (pH 7.5)-7 M urea and applied to a DEAE-Sephadex A-25 column (1 X 1-cm) equilibrated with the same buffer. Elution was performed with a 50-ml linear gradient of 0.3-1.0 M NaCl in 5 mM Tris-HCl (pH 7.5)-7 M urea (15).Isolation of Poly(A) Segments by Oligo(dT)-Cellulose Chromatography. RNase digests (0.2 ml) of terminally labeled 60-70S or 30-40S viral RNA were diluted to 3 ml in 10 mM Tris HCl (pH 7.5)-0.5 M KCl and applied to oligo(dT)-cellulose columns (0.6 X 3-cm) equilibrated with the same buffer as described (25,26). 2386Abbreviations: HnRNA, heterogeneous nuclear ribonucleic acid; rRNA, ribosomal RNA; MSV(MLV), murine sarcoma-leukemia virus.

show abstract

Virus-Specific Messenger RNA and Nascent Polypeptides in Polyribosomes of Cells Replicating Murine Sarcoma-Leukemia Viruses

Cited by 21 publications

References 24 publications

The 7S RNA Common to Oncornaviruses and Normal Cells is Associated with Polyribosomes

The 7S RNA Common to Oncornaviruses and Normal Cells is Associated with Polyribosomes

RNA Processing and RNA Tumor Virus Origin and Evolution

The Homopolyadenylate and Adjacent Nucleotides at the 3′-Terminus of 30-40S RNA Subunits in the Genome of Murine Sarcoma-Leukemia Virus

Contact Info

Product

Resources

About