Caister Academic Press

Functions and Mechanism of Action of the Herpes Simplex Virus Type Regulatory Protein, ICP4

Neal A. DeLuca
from: Alphaherpesviruses: Molecular Virology (Edited by: Sandra K. Weller). Caister Academic Press, U.K. (2011)


ICP4 is expressed from the HSV genome very early in infection. It is a large structurally complex nuclear phosphoprotein that is essential for viral growth largely due to its requirement for the transcriptional activation of most HSV early and late genes. It also acts a repressor of transcription under certain circumstances. The HSV genome is transcribed by RNA polII, and ICP4 interacts with components of the RNA polII transcription machinery to carry out is functions in transcription. The interactions that are important for its functions can be genetically defined implicating a modular composition of the ICP4 protein. ICP4 also plays a specific role in virus growth in sympathetic neurons implicating a specific function in pathogenesis. This is a review about what is known about ICP4 from many genetic, biological and biochemical studies, from many laboratories read more ...
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