Formation of Rous associated virus-60: origin of the polymerase gene

Sawyer, Robert C.; Rettenmier, Carl W.; Hanafusa, Hidesaburô

doi:10.1128/jvi.29.3.856-862.1979

Cited by 3 publications

(2 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…6). This phenomenon has been described before (16,44). Both pol+ and pol-NP clones exhibited only the normal-sized genomic RNA and src mRNA and produced virions containing essentially only the genomic RNA.…”

Section: It Componentssupporting

confidence: 60%

Deletion in the 3' pol sequence correlates with aberration of RNA expression in certain replication-defective avian sarcoma viruses

Wang¹

1985

J Virol

View full text Add to dashboard Cite

The RNA expression of a series of replication-defective recovered avian sarcoma viruses (rASVs) were studied. Abnormal-sized viral RNAs, both larger and smaller than the genome, were observed in the nonproducer cells infected with rASVs containing env and pol deletions. Each nonproducer clone contained a single provirus integrated at a unique site and expressed a unique RNA pattern. Upon rescuing of the sarcoma virus with a helper virus and subsequent cloning, the RNA pattern of individual nonproducer clones again displayed variation according to the integration sites. This was not seen in nondefective rASV or in rASVs containing only an env deletion. The aberrant RNA expression did not result from the lack of reverse transcriptase activity per se, since neither nonconditional nor temperature-sensitive mutants of RSV expressed abnormal viral RNAs in the absence of a functional reverse transcriptase. The abnormal RNA patterns could not be corrected in trans by helper virus functions. The unusual-sized RNAs in env pol-rASV-infected cells are not due to splicing to alternative acceptor sites for src mRNA because there are no extra viral sequences between the 5' leader and the src sequences; instead, they are due to the presence of extra sequences, most likely of cellular origin, at the 3' ends of the viral RNAs. Based upon the extent of deletions in the viral genomes, the data suggest that deletion in the 3' pol region of those rASVs results in a cis effect on the transcription and processing of the 3' ends of viral RNAs. The unusual-sized viral RNAs are most likely due to read-through transcription from the right-hand terminus of provirus into downstream cellular sequences, followed by cleavage and polyadenylation at multiple sites of the 3' region of the RNA transcripts. The extent of read-through transcription appears to depend on the chromosomal location of the provirus.

show abstract

Section: It Componentssupporting

confidence: 60%

Deletion in the 3' pol sequence correlates with aberration of RNA expression in certain replication-defective avian sarcoma viruses

Wang¹

1985

J Virol

View full text Add to dashboard Cite

show abstract

“…Biol., in press), RNA (26), and protein (7), appears to extend from the 3' end of the gag gene (coding for p15) into the 5' portion of pol (7,19,24). The RAV-60 genetic information corresponding to this deletion is thus derived from the exogenous parent (21). Intragenic recombination can occur, however, within the 5' portion ofgag (18,22).…”

mentioning

confidence: 99%

Induction of neoplasms by subgroup E recombinants of exogenous and endogenous avian retroviruses (Rous-associated virus type 60)

Crittenden¹,

Hayward²,

Hanafusa³

et al. 1980

J Virol

Self Cite

View full text Add to dashboard Cite

Chickens susceptible to infection with subgroup E viruses were inoculated with four independent isolates of Rous-associated virus type 60 (RAV-60) that are subgroup E recombinants of endogenous and exogenous virus. Neoplasms developed in each inoculated group. Therefore, nontransforming viruses of subgroup E can induce lymphoid leukosis at a moderate rate compared with RAV-0, a subgroup E endogenous virus, suggesting that oncogenicity is not a viral envelope (env)-related characteristic. Since the common (c) regions of the RAV-60s examnined were of exogenous origin, we suggest that the c region rather than env is important for a high rate of induction of lymphoid leukosis and related neoplasms.

show abstract

Cellular Compartmentalization in Insulin Action: Altered Signaling by a Lipid-Modified IRS-1

Kriauciunas

Myers²,

Kahn

2000

Molecular and Cellular Biology

View full text Add to dashboard Cite

While most receptor tyrosine kinases signal by recruiting SH2 proteins directly to phosphorylation sites on their plasma membrane receptor, the insulin receptor phosphorylates intermediary IRS proteins that are distributed between the cytoplasm and a state of loose association with intracellular membranes. To determine the importance of this distribution to IRS-1-mediated signaling, we constructed a prenylated, constitutively membrane-bound IRS-1 by adding the COOH-terminal 9 amino acids from p21 ras , including the CAAX motif, to IRS-1 (IRS-CAAX) and analyzed its function in 32D cells expressing the insulin receptor. IRS-CAAX migrated more slowly on sodium dodecyl sulfate-polyacrylamide gel electrophoresis than did IRS-1 and demonstrated increased levels of serine/threonine phosphorylation. Insulin-stimulated tyrosyl phosphorylation of IRS-CAAX was slightly decreased, while IRS-CAAX-mediated phosphatidylinositol 3-kinase (PI3-kinase) binding and activation were decreased by approximately 75% compared to those for wild-type IRS-1. Similarly, expression of IRS-CAAX desensitized insulin-stimulated [ 3 H]thymidine incorporation into DNA by about an order of magnitude compared to IRS-1. By contrast, IRS-CAAX-expressing cells demonstrated increased signaling by mitogen-activated protein kinase, Akt, and p70 S6 kinase in response to insulin. Hence, tight association with the membrane increased IRS-1 serine phosphorylation and reduced coupling between the insulin receptor, PI3-kinase, and proliferative signaling while enhancing other signaling pathways. Thus, the correct distribution of IRS-1 between the cytoplasm and membrane compartments is critical to the normal balance in the network of insulin signaling.Many growth factors regulate cellular processes through activation of tyrosine kinases (11,55,58). Ligand binding to the extracellular region of the receptor results in activation of the intracellular tyrosine kinase domain of the receptor and receptor autophosphorylation (35). In most cases, tyrosyl autophosphorylation of the intracellular portion of the receptor directly recruits binding of downstream signaling partners through specialized phosphotyrosine-binding domains, e.g., SH2 domains in signaling proteins (26). The receptor thus nucleates a signaling complex containing numerous SH2 domain-containing signaling proteins (SH2 proteins) on the plasma membrane.The insulin receptor, like most growth factor receptors, contains intrinsic tyrosine kinase activity and undergoes tyrosine autophosphorylation during ligand stimulation (35). However, unlike most other growth factor receptors, the insulin receptor does not directly recruit SH2 proteins. Instead, the insulin receptor phosphorylates intracellular substrate proteins (such as the IRS proteins, IRS-1, IRS-2, IRS-3, and IRS-4) on multiple tyrosine residues, and these IRS proteins in turn recruit SH2 proteins such as phosphatidylinositol 3Ј-kinase (PI3Ј-kinase), GRB-2/mSos, and SHP-2 into a signaling complex (35). Previous studies have shown that the IRS protein...

show abstract

Formation of Rous associated virus-60: origin of the polymerase gene

Cited by 3 publications

References 47 publications

Deletion in the 3' pol sequence correlates with aberration of RNA expression in certain replication-defective avian sarcoma viruses

Deletion in the 3' pol sequence correlates with aberration of RNA expression in certain replication-defective avian sarcoma viruses

Induction of neoplasms by subgroup E recombinants of exogenous and endogenous avian retroviruses (Rous-associated virus type 60)

Cellular Compartmentalization in Insulin Action: Altered Signaling by a Lipid-Modified IRS-1

Contact Info

Product

Resources

About