Identification of a 30S RNA with properties of a defective type C virus in murine cells

Self Cite

RNA species with properties of defective retrovirus-like 30S RNA genomes have previously been detected in both rats and mice and in some rat and mouse retroviruses. Using cell lines which express high levels ofthis retrovirus-like RNA, we formed pseudotypes of the 30S RNAs with helper-independent type C viruses. A pseudotype virus complex containing a mouse 30S subunit was transmitted to rat cells, and a pseudotype virus complex containing a rat 30S subunit was transmitted to bat cells. In other transmission experiments, a rat 30S subunit was isolated in nonproducer bat cells without detectable expression of the helperindependent type C virus used to pseudotype it. The results provide further support for the retrovirus-like nature of the rat 308 subunit and provide evidence which supports the protovirus hypothesis proposed by Temin.

mentioning

confidence: 99%

mentioning

confidence: 99%

Defective retrovirus-like 30S RNA species of rat and mouse cells are infectious if packaged by type C helper virus

Scolnick¹,

Vass²,

Howk³

et al. 1979

Self Cite

“…Homology was observed with LTR sequences of murine VL30 elements, a retroviruslike gene family encoding 30S mRNA molecules which appear to contain signals for virion packaging, replication, and proviral integration but lack functional replicative genes and genes for viral structural proteins; VL30 elements can be transmitted as pseudovirions. (2,29,35).…”

Section: Resultsmentioning

confidence: 99%

“…This subclone was characterized to unequivocally establish the presence of retroviral sequences within the MHC. The results of blot hybridization and sequence analysis suggest that TLevl is a retroviral element which contains two types of sequences: those which share strong homology with mouse VL30 elements (2,15,29,34) and those which are weakly homologous to MuLV sequences.…”

mentioning

confidence: 99%

Isolation of a retroviruslike sequence from the TL locus of the C57BL/10 murine major histocompatibility complex

Pampeno¹,

Meruelo²

1986

Two retroviruslike sequences have been isolated from the TL locus of the major histocompatibility complex of C57BL/10 mice. One sequence (TLev2) hybridizes only with probes derived from the pol region of the murine leukemia provirus AKR; the other sequence (TLevl) hybridizes with gag, pol, and env AKR region probes. This 9-kilobase endogenous, TL region-associated virus (TLevl) has been further characterized. The TLevl genome has been shown to contain murine leukemia virus-related sequences bounded by retroviruslike, VL30 long terminal repeats. Hybridization of TLevl-derived probes to mouse genomic digests reveals multiple copies which show distinct patterns compared with those observed with murine leukemia virus probes. The study of TLevl may prove significant with respect to the interaction of retroviral sequences within the genome, expression of genes within the TL locus, and polymorphisms within the major histocompatibility complex. * Corresponding author. of NZB xenotropic and an amphotropic virus were gifts of Raymond R. O'Neill, National Institutes of Health. An endogenous VL30 BVL-1 (26) clone was a gift of Micheal Getz, Mayo Clinic Foundation, Rochester, Minn.DNA preparation. (i) High-molecular-weight genomic DNA. Cells were washed and suspended in buffer containing 50 mM Tris (pH 7.5), 150 mM NaCl and 2 mM EDTA at a 296 on August 5, 2020 by guest

“…VL30 elements are a family of retrotransposons present at about 50 copies per haploid genome in rats and mice (2,3,23,24); these elements share features with endogenous retroviruses, including regions of sequence similarity to retroviral gag and pol genes and long terminal repeat regions (27,35). Retroviral packaging signals and primer binding sites allow them to be efficiently packaged by retroviruses and copied to DNA by retroviral reverse transcriptase.…”

mentioning

confidence: 99%

Anoxia-inducible rat VL30 elements and their relationship to ras-containing sarcoma viruses

Firulli

Anderson

Stoler

et al. 1993

VL30 elements are associated with cancer by their overexpression in rodent malignancies, their induction in a fibroblast response to anoxia which shares features with the malignant phenotype, and their presence recombined into Harvey murine sarcoma virus (HaSV) and Kirsten murine sarcoma virus. These sarcoma viruses contain ras oncogenes flanked on both sides by retrotransposon VL30 element sequences, in turn flanked by mouse leukemia virus sequences. Three very basic questions have existed about the VL30 element sequences found in sarcoma viruses: (i) how did they become recombined, (ii) what are their exact boundaries, and (iii) why are they there? To help decipher the nature of VL30 elements in sarcoma viruses, we examined VL30 clones isolated from an anoxic fibroblast cDNA library and independently by polymerase chain reaction cloning from rat cell DNA. Sequence comparisons with HaSV revealed that HaSV was formed by the substitution of 0.7 kb of VL30 sequences by 0.9 kb of c-Ha-ras sequences, with this event possibly facilitated by the presence of an identical Alu-like repeat found upstream of the 5' recombination point in both the VL30 element and c-Ha-ras. Recombination occurred 42 bases beyond the Alu-like sequences in VL30 and 1596 bases beyond them in c-Ha-ras, at position 926 of HaSV. The 3' ras-VL30 recombination event in HaSV occurred within a seven-base region of shared sequence identity, between HaSV bases 1825 and 1825 and 1831. Recombination between Moloney leukemia virus (MoLV) and VL30 appears to have occurred at a point corresponding to base 218 or 219 of MoLV and was near a TAR-like VL30 sequence; such recombination at the 3' end was between positions 7445 and 7456 of MoLV (HaSV positions 4694 to 4703). Kirsten murine sarcoma virus was found to be closely analogous to HaSV, and limited similar features were also seen with Rasheed sarcoma virus.