Role of the Nonstructural Polyproteins in Alphavirus RNA Synthesis

  • Dorothea L. Sawicki
  • Stanley G. Sawicki
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 440)


Alphaviruses are of general interest because they replicate in such a broad range of animals, including invertebrates as well as mammals and birds. This broad replicative potential is an essential part of their transmission strategy. The successful synthesis of many infectious progeny starts with the translation of the genome into the viral nonstructural proteins (nsPs) that form an unstable viral RNA-dependent RNA polymerase activity, which copies the infecting genome into a complementary, or minus-strand, RNA template of genome-length. Complexes composed of the minus-strand templates and long-lived viral replicases or transcriptases then produce throughout the rest of the infectious cycle large amounts of genomes or via internal initiation of a 3’-co-terminal, subgenomic mRNA. The 26S mRNA serves as a template for translation of the viral capsid and envelope proteins. Thus, the crucial step after an alphavirus enters the cell is the formation of the initial replication complex that produces minus-strand RNA since the number of minus strand templates that form during the early part of the infectious cycle determines the amount and rate of viral plus-strand RNA synthesis. This review will highlight research efforts directed toward understanding the synthesis of alphavirus RNA and its regulation.


Nonstructural Protein Strand Synthesis Semliki Forest Virus Sindbis Virus Alfalfa Mosaic Virus 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • Dorothea L. Sawicki
    • 1
  • Stanley G. Sawicki
    • 1
  1. 1.Department of Microbiology and ImmunologyMedical College of OhioToledoUSA

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