Phosphorylation of herpes simplex virus type 1 Us11 protein is independent of viral genome expression

ABSTRACT During entry, herpes simplex virus type 1 (HSV-1) releases its capsid and the tegument proteins into the cytosol of a host cell by fusing with the plasma membrane. The capsid is then transported to the nucleus, where it docks at the nuclear pore complexes (NPCs), and the viral genome is rapidly released into the nucleoplasm. In this study, capsid association with NPCs and uncoating of the viral DNA were reconstituted in vitro. Isolated capsids prepared from virus were incubated with cytosol and purified nuclei. They were found to bind to the nuclear pores. Binding could be inhibited by pretreating the nuclei with wheat germ agglutinin, anti-NPC antibodies, or antibodies against importin β. Furthermore, in the absence of cytosol, purified importin β was both sufficient and necessary to support efficient capsid binding to nuclei. Up to 60 to 70% of capsids interacting with rat liver nuclei in vitro released their DNA if cytosol and metabolic energy were supplied. Interaction of the capsid with the nuclear pore thus seemed to trigger the release of the viral genome, implying that components of the NPC play an active role in the nuclear events during HSV-1 entry into host cells.

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Inhibition of PACT-Mediated Activation of PKR by the Herpes Simplex Virus Type 1 Us11 Protein

Journal of Virology ◽

10.1128/jvi.76.21.11054-11064.2002 ◽

2002 ◽

Vol 76 (21) ◽

pp. 11054-11064 ◽

Cited By ~ 80

Author(s):

Gregory A. Peters ◽

David Khoo ◽

Ian Mohr ◽

Ganes C. Sen

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Virus Type ◽

Herpes Simplex Virus Type ◽

Cellular Protein ◽

Simplex Virus ◽

Us11 Protein

ABSTRACT PACT, a protein activator of PKR, can cause inhibition of cellular protein synthesis and apoptosis. Here, we report that the Us11 protein of herpes simplex virus type 1 can block PKR activation by PACT both in vitro and in vivo. Although Us11 can bind to both PKR and PACT, mutational analyses revealed that the binding of Us11 to PKR, and not to PACT, was essential for its inhibitory action. Similar analyses also revealed that the inhibitory effect was mediated by an interaction between the C-terminal half of Us11 and the N-terminal domain of PKR. The binding of Us11 to PKR did not block the binding of PKR to PACT but prevented its activation. Us11 is the first example of a viral protein that can inhibit the action of PACT on PKR.

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Use of herpes simplex virus type 1 for transgene expression within the nervous system*

Clinical Science ◽

10.1042/cs0960533 ◽

1999 ◽

Vol 96 (6) ◽

pp. 533-541 ◽

Cited By ~ 6

Author(s):

Robin H. LACHMANN ◽

Stacey EFSTATHIOU

Keyword(s):

Gene Therapy ◽

Nervous System ◽

Herpes Simplex Virus ◽

Herpes Simplex ◽

Virus Type ◽

Herpes Simplex Virus Type ◽

Viral Genome ◽

Latently Infected ◽

Simplex Virus

Gene therapy might provide a useful treatment for a number of neurological diseases and a great deal of effort is going into the development of vector systems which will allow the delivery of potentially therapeutic genes to terminally differentiated neurons within the intact mammalian brain. The ability of herpes simplex virus type 1 (HSV-1) to establish a lifelong latent infection within neurons has led to interest in its use as a neuronal gene delivery vector. During HSV latency no viral proteins are produced and transcription from the latent viral genome is limited to a family of nuclear RNAs, the latency-associated transcripts, whose function is not well understood. Obtaining prolonged expression of a transgene in latently infected neurons has proven difficult due to transcriptional silencing of exogenous promoters introduced into the latent viral genome. For this reason there is a great deal of interest in utilizing the HSV latency-associated promoter to drive the expression of therapeutic genes in latently infected neurons of both the peripheral and central nervous systems. In this review we describe a strategy which allows the latency-associated promoter to drive long-term reporter gene expression in the mammalian nervous system. These observations open up the possibility of using similar HSV-based vectors to express therapeutic transgenes within the brain and investigate the potential of gene therapy in a range of neurological disorders.

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