Academic Commons

Synthesis of Reovirus Oligo Adenylic Acid In Vivo and In Vitro

Silverstein, Samuel C.; Astell, Caroline; Christman, Judith; Klett, Hannah; Acs, George

The formation of reovirus double-stranded (ds) RNA and of oligo adenylic acid (oligo A) is inhibited by 5 μg of actinomycin D per ml added at the time of viral infection. Viral proteins are synthesized and assembled into dsRNA-deficient particles under these conditions. The addition of cycloheximide to infected cells during the mid-logarithmic phase of viral replication terminates protein and dsRNA synthesis, but allows continued oligo A synthesis for about 1 h. The 3H-labeled oligo A formed in the presence of cycloheximide is incorporated into particles whose density in CsCl is identical to that of reovirions. Using the large particulate or virus factory-containing cytoplasmic fraction of infected L-cells, we have established an in vitro system for the synthesis of oligo A. The in vitro product migrates slightly faster in sodium dodecyl sulfate acrylamide gels than marker oligo A. Oligo A synthesis in vitro continues for about 1 h, requires, the presence of only one ribonucleoside triphosphate (ATP), is not inhibited by DNase or RNase, but is abruptly terminated by the addition of chymotrypsin to the reaction mixture. Oligo A formed both in vivo and in vitro is released from the factory fraction by chymotrypsin digestion. The enzymes which catalyze the synthesis of oligo A, dsRNA, and single-stranded RNA all exhibit a similar temperature dependence with an optimum of ∼45 C. These results indicate that oligo A is formed within the core of the nascent virion after the completion of dsRNA synthesis; they suggest that the oligo A polymerase is an alternative activity of the virion-bound transcriptase and that it is regulated by outer capsomere proteins.


  • thumnail for J._Virol.-1974-Silverstein-740-52.pdf J._Virol.-1974-Silverstein-740-52.pdf application/pdf 2.46 MB Download File

Also Published In

American Society for Microbiology

More About This Work

Academic Units
Physiology and Cellular Biophysics
Journal of Virology
Published Here
January 19, 2016
Academic Commons provides global access to research and scholarship produced at Columbia University, Barnard College, Teachers College, Union Theological Seminary and Jewish Theological Seminary. Academic Commons is managed by the Columbia University Libraries.