Viral translation is coupled to transcription in Sindbis virus-infected cells.
During the late phase of Sindbis virus infection, the viral subgenomic mRNA is translated efficiently in BHK cells, whereas host protein synthesis is inhibited. However, transfection of in vitro-generated Sindbis virus subgenomic mRNA leads to efficient translation in uninfected BHK cells, whereas it is a poor substrate in infected cells. Therefore, the structure of the subgenomic mRNA itself is not sufficient to confer its translatability in infected cells. In this regard, translation of the subgenomic mRNA requires synthesis from the viral transcription machinery. The lack of translation of transfected viral mRNAs in infected cells is not due to their degradation nor is it a consequence of competition between viral transcripts and transfected mRNAs, because a replicon that cannot produce subgenomic mRNA also interferes with exogenous mRNA translation. Interestingly, subgenomic mRNA is translated more efficiently when it is transfected into uninfected cells than when it is transcribed from a transfected replicon. Finally, a similar behavior was observed for other RNA viruses, such as vesicular stomatitis virus and encephalomyocarditis virus. These findings support the notion that translation is coupled to transcription in cells infected with different animal viruses.
Sanz
Miguel A
MA
Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Facultad de Ciencias, Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain. masanz@cbm.uam.es
Castelló
Alfredo
A
Carrasco
Luis
L
D018354:Alphavirus Infections / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D004686:Encephalomyocarditis virus / Q000502:physiology; D016679:Genome, Viral / Q000502:physiology*; D014176:Protein Biosynthesis / Q000502:physiology*; D020871:RNA Stability / Q000502:physiology; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism*; D012845:Sindbis Virus / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology*; D014721:Vesicular stomatitis Indiana virus / Q000502:physiology
D012367:RNA, Viral