Regulatory transcriptional protein, which trans-activates gene expression from early baculovirus promoters. Can also trans-activate its own promoter, suggesting an autoregulation during infection of host cells. Promotes also viral DNA genome replication via the N-terminal region. Homodimer. Interacts with helicase and LEF-3. The spliced form of IE-1 was expressed only in the first 6 hours postinfection, whereas the nonspliced IE-1 transcript was expressed at constant level up to 24 hours. The N-terminal region is required for origin-specific DNA replication and phosphorylation. Phosphorylated. Contains 54 additional residues in the N-terminus. Belongs to the nucleopolyhedrovirus IE-1 protein family. Extended N-terminus.