Evidence for the internal location of actin in the pseudorabies virion

Pseudorabies virions were purified by sucrose gradient and virion-associated proteins were examined. Cytoskeleton actin was found to be a component of virion preparation. In addition, abundant virion-associated actin was detected even after the virion preparation was treated with trypsin digestion or the viral envelope was removed by Triton X-100. This finding indicated that the location of actin is inside the pseudorabies virion. Furthermore, the possible involvement of actin in the life cycle of pseudorabies virus was studied by using cytochalasin D, an F-actin binding drug, and the result showed that cytochalasin D reduced the number of plaques and the size of the plaque of pseudorabies virus.