Comparison of the 3′ Termini of Discrete Segments of the Double-Stranded Ribonucleic Acid Genomes of Cytoplasmic Polyhedrosis Virus, Wound Tumor Virus, and Reovirus

The poly(A) sequence of 30 to 40S Rous sarcoma virus RNA, prepared by digestion of the RNA with RNase T, showed a rather homogenous electrophoretic distribution in formamide-polyacrylamide gels. Its size was estimated to be about 200 AMP residues. The poly(A) appears to be located at or near the 3' end of the 30 to 40S RNA because: (i) it contained one adenosine per 180 AMP residues, and because (ii) incubation of 30 to 40S RNA with bacterial RNase H in the presence of poly(dT) removed its poly(A) without significantly affecting its hydrodynamic or electrophoretic properties in denaturing solvents. The viral 60 to 70S RNA complex was found to consist of 30 to 40S subunits both with (65%) and without (approximately 30%) poly(A). The heteropolymeric sequences of these two species of 30 to 40S subunits have the same RNase T,-resistant oligonucleotide composition. Some, perhaps all, RNase T,-resistant oligonucleotides of 30 to 40S Rous sarcoma virus RNA appear to have a unique location relative to the poly(A) sequence, because the complexity of poly(A)-tagged fragments of 30 to 40S RNA decreased with decreasing size of the fragment. Two RNase T,-resistant oligonucleotides which distinguish sarcoma virus Prague B RNA from that of a transformation-defective deletion mutant of the same virus appear to be associated with an 11S poly(A)-tagged fragment of Prague B RNA. Thus RNA sequences concerned with cell transformation seem to be located within 5 to 10% of the 3' terminus of Prague B RNA. Poly(A) stretches have been found in the RNA of tumor viruses and many cytocidal viruses as well as in many cellular messenger and heterogenous nuclear RNAs (

Section: Resultsmentioning

confidence: 99%

Properties and Location of Poly(A) in Rous Sarcoma Virus RNA

Wang

Duesberg

1974

“…The terminal sequences of the dsRNA segments have been of significant interest in relation to understanding mechanisms of transcription initiation and assembly of genome segments. Furuichi and Miura (10) and Lewandowski and Leppla (17) have found previously that CPV genome RNAs contain approximately an equal amount of U and C as 3' termini by analyzing the 3'-terminal nucleosides of the dsRNA segments labeled by periodate oxidation followed by reduction with [3H]borohydride. Furuichi and Miura subsequently found that each of the genome segments contain common 3' termini, PyC and PyU (Py, pyrimidine) for plus and minus strands, respectively (11).…”

mentioning

confidence: 99%

Homologous Terminal Sequences in the Double-Stranded RNA Genome Segments of Cytoplasmic Polyhedrosis Virus of the Silkworm Bombyx mori

Kuchino¹,

Nishimura²,

Smith

et al. 1982

The 3'-terminal regions (20 to 32 residues) of the genome double-stranded RNA (dsRNA) segments of cytoplasmic polyhedrosis virus were sequenced. The dsRNAs, which were labeled at their 3' termini by incubation with [5'-32P]pCp and T4 RNA ligase, were denatured and resolved into the plus and minus strands by agarose-urea gel electrophoresis. Ten single-stranded RNAs thus obtained from the five dsRNA segments IV, V, VIII, IX, and X were sequenced by postlabeling methods. Common 3'-terminal sequences,-GUUAGCC and-UUACU, were found in the plus and minus strands, respectively, of all five dsRNA segments. However, adjacent sequences diverged and were considerably variable. The homologous sequences found in the 3' end may be important recognition signals for viral RNA polymerases and for assembly of the genome segments. Cytoplasmic polyhedrosis virus (CPV), which infects the silkworm Bombyx mori, is the prototype of insect viruses that have genomes consisting of 10 segments of double-stranded (ds) RNA (20). The molecular weights of these dsRNA segments range from 0.35 x 106 to 2.55 x 106 (6), and they are considered to code for viralspecific polypeptides as monocistronic genes, like human reovirus (19). CPV contains dsRNAdependent RNA polymerase that transcribes the duplex genome RNA to form mRNA either in the infected animal or under appropriate conditions in vitro (16, 23, 24). In addition to RNA polymerase, CPV contains other enzymes required for the formation of complete mRNA with a capped 5' terminus, m7GpppA'pG-(12).

“…Previous results suggested to us a potential relationship between reovirus core particles and purified CPV. Reovirus cores and CPV possess similar segmented dsRNA genomes of approximately 15 x 106 daltons (14), similar buoyant densities in CsCl, 1.435 4 0.005 g/cm3 (25,15), and similar transcriptase activities demonstrable…”

Section: Resultsmentioning

confidence: 99%

“…Once the molecular weights of the CPV polypeptide were determined, it was of interest to see if, as appears to be the case for reovirus (37), a clear correspondence exists between the size of the dsRNA segments and the size of the discrete viral polypeptides. The genome of CPV consists of 10 discrete dsRNA segments ranging in size from the largest, estimated at 2.7 X 106 daltons, to the smallest, at 0.37 X 106 daltons (14). It would appear (Table 1) that viral polypeptides I through V could be coded for by dsRNA segments I, II, III, VI, and VIII, respectively.…”

mentioning

confidence: 99%

Comparison of the Structure and Polypeptide Composition of Three Double-Stranded Ribonucleic Acid-Containing Viruses (Diplornaviruses): Cytoplasmic Polyhedrosis Virus, Wound Tumor Virus, and Reovirus

Lewandowski

Traynor

1972

Iodination of reovirus, cytoplasmic polyhedrosis virus (CPV), and wound tumor virus (WTV), and their respective subviral forms, followed by analysis of the labeled polypeptides by using polyacrylamide gel electrophoresis, has been used to compare the protein contents of these three diplornaviruses. This approach, when combined with electron microscopy and buoyant density determinations, appears capable of localizing individual polypeptides in some of the viral and subviral forms. CPV (p = 1.435 g/cm3) seems to resemble reovirus cores (p = 1.440 g/cm3) in both ultrastructure and polypeptide composition. CPV is composed of five polypeptides with molecular weights of about 151