The Roles of ICP0 During HSV-1 Infection
Roger D. Everett
from: Alpha Herpesviruses: Molecular and Cellular Biology (Edited by: R. M. Sandri-Goldin). Caister Academic Press, U.K. (2006)
ICP0, one of the five immediate-early proteins encoded by herpes simplex virus type 1 (HSV-1), plays a central role in regulating whether the virus progresses to lytic or latent infection. ICP0 is a member of the family of E3 ubiquitin ligase enzymes that have a so-called RING finger zinc-binding domain. This domain confers on ICP0 the ability to induce the proteasome-dependent degradation of a number of cellular proteins. This process results in multiple consequences, including the disruption of cellular nuclear sub-structures known as ND10 or PML nuclear bodies. Interestingly, prior to the disruption of ND10, parental HSV-1 genomes become closely associated with these structures during the early stages of HSV-1 infection. The E3 ubiquitin ligase activity of ICP0 correlates very well with its role in the stimulation lytic virus infection and induction of reactivation of latent or quiescent viral genomes. However, despite intensive investigation, the mechanism of the connection between the E3 ubiquitin ligase activities of ICP0 and its roles during HSV-1 infection remain poorly understood. This chapter summarises recent work on the biochemical and biological activities of ICP0, and discusses the possible mechanisms that might explain how ICP0 regulates HSV-1 infection read more ...