The pk-1 Gene of Autographa Californica Multinucleocapsid Nuclear Polyhedrosis Virus Encodes a Protein Kinase

Abstract

Open reading frame (ORF) 9 of the EcoRI I fragment of the baculovirus Autographa californica multinucleocapsid nuclear polyhedrosis virus (AcMNPV) genome encodes a protein, PK-1, which has strong similarity to serine-threonine protein kinases. The published sequence of the pk-1 gene contains an error that, when corrected, extends the ORF by 228 nucleotides. Transcription of pk-1 was first detectable by primer extension at 12 h post-infection, accumulating to high levels during the very late phase of infection. PK-1 produced in rabbit reticulocyte lysates was able to phosphorylate histone H1. Together, our results suggest that ORF 9 encodes a protein kinase that is expressed during the beginning of the late and throughout the very late phases of AcMNPV infection.