Autographa californica nuclear polyhedrosis virus phosphoproteins and synthesis of intracellular proteins after virus infection.

Polypeptides and phosphoproteins isolated from nuclear and cytoplasmic fractions of TN-368-10 cells infected with Autographa californica nuclear polyhedrosis virus (AcMNPV) were analyzed by polyacrylamide gel electrophoresis. Likewise, AcMNPV extracellular virus and alkali-released virus were compared. ACMNPV extracellular virus possessed at least nine phosphoproteins while the alkali-released virus had about 14 phosphoproteins. The major structural polypeptide of AcMNPV, polyhedrin, was phosphorylated. Intracellular proteins of infected TN-368-10 cells were pulse-labeled with [35S]methionine and separated into nuclear and cytoplasmic fractions. At least 36 virus-induced polypeptides were detected in infected cells, and several polypeptides were found as early as 5 hr postinfection. The patterns of synthesis and appearance of infected cell polypeptides were complex, but polypeptide differences between nuclear and cytoplasmic fractions were detected. Twenty phosphoproteins labeled with 32P were also detected in the two fractions, and at least six had electrophoretic mobilities similar to virus-associated phosphoproteins.