| Autor: |
Harold E. Varmus, Nancy Quintrell, J. Michael Bishop, Brian W.J. Mahy, Chun-Tsan Deng, Edward Stavnezer |
| Rok vydání: |
1976 |
| Předmět: |
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| DOI: |
10.1016/b978-0-12-077350-3.50004-6 |
| Popis: |
Cells infected with avian sarcoma virus synthesize viral RNA by transcribing an integrated DNA provirus. Transcription is catalyzed by an RNA polymerase of the host and may initiate outside of the provirus, generating a precursor which must be further processed in order to produce mature viral genome and messengers. Infected cells contain small amounts of RNA complementary to the viral genome, but the principal stable products of viral RNA synthesis are molecules with polarity identical to that of the viral genome. The production of viral messengers can be interrupted by the antibiotic cordycepin without major effect on primary transcription. Avian cells producing virus contain at least two separate classes of viral messenger RNA (mol. wts. ca. 3 & times; 10 6 and 1.3 & times; 10 6 ) which could permit independent expression of different viral genes. Mammalian cells transformed by avian sarcoma virus but not producing virus probably transcribe provirus into a large nuclear RNA (mol. wt. ca. 3 & times; 10 6 ), but only the smaller class of viral messenger (1.3 & times; 10 6 ) is detectable in cytoplasm and at least one viral gene (envelope glycoprotein) may not be represented in the messengers. Avian sarcoma virus-infected hamster cells which have reverted to a normal phenotype retain provirus and generate messenger for the viral transforming gene, but the amount of this message is substantially smaller than in the parental transformed cells; we can account for the revertant phenotype only by attributing it to a reduction in dose for the product of the viral transforming gene. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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