Inhibition of Protein Synthesis in Newcastle Disease Virus Infected L Cells 1

Summary The nature of the inhibition of cellular protein synthesis in NDV infected L cells has been examined and found to be a consequence of inhibitions at both transcriptional and translational levels. It was determined that the inhibition of protein synthesis was not a result of viral attachment, any detectable toxic substance associated with the infecting virion, the depletion of intracellular amino acids, or an inhibition of amino acid uptake. The inhibitory action of the virus could be completely reversed by the addition of FPA prior to 5 hr after infection. Thereafter, the effectiveness of the analog in reversing the inhibition of protein synthesis continually diminished. Consequently, the inhibition of cellular protein synthesis was found to be closely associated with proteins synthesized relatively late in the cycle of NDV replication in L cells.