Infected cell protein 4 (ICP4)

Infected cell protein 4 (ICP4) is a major regulatory protein encoded by the herpes simplex virus type 1 (HSV-1) and also present in HSV-2. It is essential for productive viral infection and plays a central role in regulating viral gene expression at the transcriptional level, acting both as an activator and repressor of transcription.

Infected cell protein 4 (ICP4) is a major regulatory protein that regulates viral gene expression at the transcriptional level, acting both as an activator and repressor of transcription. It interacts directly with components of the host RNA polymerase II machinery, including TATA box-binding protein (TBP), TFIIB, TBP-associated factor 1 (TAF1), and other elements within the TFIID complex.