Impaired cleavage of the joint gag-pol polyprotein precursor and virion assembly in a temperature-sensitive mutant of Rous sarcoma virus.
Virology
; 135(2): 489-502, 1984 Jun.
Article
en En
| MEDLINE
| ID: mdl-6330981
ABSTRACT
A temperature-sensitive coordinate mutant tsLA83 of Prague (PR-B) strain of Rous sarcoma virus at the nonpermissive temperature (41 degrees) produces noninfectious virus particles (NI-LA83) which contained only 3% of the reverse-transcriptase activity present in infectious virions. Analyses of [35S]methionine-labeled NI-LA83 showed the presence of all of the viral proteins except reverse transcriptase. Pulse-chase analyses of the virus-specified proteins in cells infected with LA83 or PR-B showed that the gag and glycoprotein precursors, Pr76gag and gPr95env, respectively, were processed at both 35 and 41 degrees. The reverse-transcriptase precursor, Pr180gag-pol, however, was not processed in LA83-infected cells at 41 degrees. In contrast, cells infected with LA83 or PR-B at 35 degrees as well as with PR-B at 41 degrees showed normal cleavage of Pr180gag-pol. A shiftdown of LA83-infected cells at 41 degrees to the permissive temperature 35 degrees resulted in the normal processing of Pr180gag-pol and production of infectious virus containing reverse transcriptase. Electron microscopic analysis showed that at 41 degrees cells infected with LA83 showed a large number of budding structures but fewer released particles. A shiftdown from 41 to 35 degrees resulted in an increase of virus particles with a concomitant decrease in budding structures suggesting that the processing of reverse-transcriptase precursor is related to virion assembly.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Precursores de Proteínas
/
Proteínas Virales
/
Virión
/
Virus del Sarcoma Aviar
/
Mutación
/
Antígenos Virales
Tipo de estudio:
Diagnostic_studies
Límite:
Animals
Idioma:
En
Revista:
Virology
Año:
1984
Tipo del documento:
Article