The Functions and Activities Of HSV-1 ICP27, a Multifunctional Regulator of Gene Expression
Rozanne M. Sandri-Goldin
from: Alphaherpesviruses: Molecular Virology (Edited by: Sandra K. Weller). Caister Academic Press, U.K. (2011)
Herpes simplex virus 1 (HSV-1) protein ICP27 is a multifunctional regulator that is essential for HSV-1 infection. ICP27 performs a number of different functions during infection that include inhibiting cellular pre-mRNA splicing, stimulating viral early and late gene transcription by recruiting cellular RNA polymerase II to viral replication sites, binding and exporting viral RNA to the cytoplasm and stimulating translation of some HSV-1 transcripts by binding translation initiation factors. ICP27 also recruits Hsc70 to nuclear foci (VICE domains) that are enriched in chaperones and components of the proteasome, and which are believed to be involved in nuclear protein quality control. ICP27 interacts with a number of proteins and it binds RNA. Post-translational modifications have been demonstrated to regulate ICP27's interactions with several proteins. NMR analysis of the N-terminus showed that it is highly flexible, which may be necessary for switching between different protein interactions. Further, ICP27 undergoes a head-to-tail intramolecular association that may also regulate its interactions, especially with proteins that require that both the N- and C-termini of ICP27 be intact for interaction. This review will cover the different activities of ICP27 and what we know about how these activities are regulated read more ...