scholarly journals Faculty Opinions recommendation of Herpes simplex virus immediate-early protein ICP22 triggers loss of serine 2-phosphorylated RNA polymerase II.

Author(s):  
Rozanne Sandri-Goldin
2007 ◽  
Vol 81 (10) ◽  
pp. 5091-5101 ◽  
Author(s):  
Kathryn A. Fraser ◽  
Stephen A. Rice

ABSTRACT During eukaryotic mRNA transcription, the synthetic activity and mRNA processing factor interactions of RNA polymerase II (RNAP II) are regulated by phosphorylation of its carboxyl-terminal domain (CTD), with modification occurring primarily on serines 2 and 5 of the CTD. We previously showed that herpes simplex virus type 1 (HSV-1) infection rapidly triggers the loss of RNAP II forms bearing serine 2 phosphorylation (Ser-2P RNAP II). Here we show that the HSV-1 immediate-early (IE) protein ICP22 is responsible for this effect during the IE phase of infection. This activity does not require the viral UL13 protein kinase, which is required for several other regulatory functions of ICP22. Additionally, we show that transient expression of ICP22 can trigger the loss of Ser-2P RNAP II in transfected cells. Thus, the ability of ICP22 to cause the loss of Ser-2 RNAP II does not require other viral factors or the context of the infected cell. Expression of the HSV-1 ICP22-related protein US1.5, which corresponds to residues 147 to 420 of ICP22, also triggers a loss of Ser-2P RNAP II in transfected cells, whereas expression of the varicella-zoster virus ICP22 homolog, ORF63, does not. Our study also provides evidence for a second, viral late gene-dependent pathway that triggers loss of Ser-2P RNAP II in infected cells, consistent with the recent work of Dai-Ju et al. (J. Q. Dai-Ju, L. Li, L. A. Johnson, and R. M. Sandri-Goldin, J. Virol. 80:3567-3581, 2006). Therefore, it appears that HSV-1 has evolved redundant mechanisms for triggering the loss of a specific phosphorylated form of RNAP II.


2021 ◽  
Author(s):  
Adam W Whisnant ◽  
Oliver Mathias Dyck Dionisi ◽  
Arnhild Grothey ◽  
Julia M Rappold ◽  
Ana Luiza Marante ◽  
...  

Transcriptional activity of RNA polymerase II (Pol II) is orchestrated by post-translational modifications of the C-terminal domain (CTD) of the largest Pol II subunit, RPB1. Herpes Simplex Virus type 1 (HSV-1) usurps the cellular transcriptional machinery during lytic infection to efficiently express viral mRNA and shut down host gene expression. The viral immediate-early protein ICP22 interferes with serine 2 phosphorylation (pS2) of the Pol II CTD by targeting CDK9. The functional implications of this are poorly understood. Here, we report that HSV-1 also induces a global loss of serine 7 phosphorylation (pS7). This effect was dependent on the expression of the two viral immediate-early proteins, ICP22 and ICP27. While lytic HSV-1 infection results in efficient Pol II degradation late in infection, we show that pS2/S7 loss precedes the drop in Pol II level. Interestingly, mutation of the RPB1 polyubiquitination site mutation K1268, which prevents proteasomal RPB1 degradation during transcription-coupled DNA repair, displayed loss of pS2/S7 but retained much higher overall RPB1 protein levels even at late times of infection, indicating that this pathway mediates bulk Pol II protein loss late in infection but is not involved in early CTD dysregulation. Using α-amanitin-resistant CTD mutants, we observed differential requirements for Ser2 and Ser7 for production of viral proteins, with Ser2 facilitating viral immediate-early gene expression and Ser7 appearing dispensable. Despite dysregulation of CTD phosphorylation and different requirements for Ser2/7, all CTD modifications tested could be visualized in viral replication compartments by immunofluorescence. These data expand the known means that HSV-1 employs to create pro-viral transcriptional environments at the expense of host responses.


1980 ◽  
Vol 26 (3) ◽  
pp. 401-404 ◽  
Author(s):  
Wai-Choi Leung

A cistron specific enzyme-forming capacity method was used to study the control of herpes simplex virus (HSV) specific deoxypyrimidine kinase (dPyK) mRNA synthesis. In this assay, the α (or immediately early) protein was required to effect the transcription of dPyK mRNA. However, the dPyK mRNA synthesis was sensitive to α-amanitin in α-amanitin sensitive cells and resistant to α-amanitin in α-amanitin resistant cells. The effective dose range of α-amanitin used and the genetic lesion in α-amanitin resistant cells suggested that cellular DNA-dependent RNA polymerase II was also involved in the transcription of dPyK. This study suggests that two components, the HSV α protein and the cellular RNA polymerase II, were required for dPyK mRNA synthesis.


2006 ◽  
Vol 80 (19) ◽  
pp. 9720-9729 ◽  
Author(s):  
Jennifer A. Corcoran ◽  
Wei-Li Hsu ◽  
James R. Smiley

ABSTRACT Herpes simplex virus (HSV) stifles cellular gene expression during productive infection of permissive cells, thereby diminishing host responses to infection. Host shutoff is achieved largely through the complementary actions of two viral proteins, ICP27 and virion host shutoff (vhs), that inhibit cellular mRNA biogenesis and trigger global mRNA decay, respectively. Although most cellular mRNAs are thus depleted, some instead increase in abundance after infection; perhaps surprisingly, some of these contain AU-rich instability elements (AREs) in their 3′-untranslated regions. ARE-containing mRNAs normally undergo rapid decay; however, their stability can increase in response to signals such as cytokines and virus infection that activate the p38/MK2 mitogen-activated protein kinase (MAPK) pathway. We and others have shown that HSV infection stabilizes the ARE mRNA encoding the stress-inducible IEX-1 mRNA, and a previous report from another laboratory has suggested vhs is responsible for this effect. However, we now report that ICP27 is essential for IEX-1 mRNA stabilization whereas vhs plays little if any role. A recent report has documented that ICP27 activates the p38 MAPK pathway, and we detected a strong correlation between this activity and stabilization of IEX-1 mRNA by using a panel of HSV type 1 (HSV-1) isolates bearing an array of previously characterized ICP27 mutations. Furthermore, IEX-1 mRNA stabilization was abrogated by the p38 inhibitor SB203580. Taken together, these data indicate that the HSV-1 immediate-early protein ICP27 alters turnover of the ARE-containing message IEX-1 by activating p38. As many ARE mRNAs encode proinflammatory cytokines or other immediate-early response proteins, some of which may limit viral replication, it will be of great interest to determine if ICP27 mediates stabilization of many or all ARE-containing mRNAs.


2009 ◽  
Vol 83 (18) ◽  
pp. 9591-9595 ◽  
Author(s):  
Zackary W. Whitlow ◽  
Thomas M. Kristie

ABSTRACT The transcriptional coactivator host cell factor 1 (HCF-1) is critical for the expression of immediate-early (IE) genes of the alphaherpesviruses herpes simplex virus type 1 (HSV-1) and varicella-zoster virus. HCF-1 may also be involved in the reactivation of these viruses from latency as it is sequestered in the cytoplasm of sensory neurons but is rapidly relocalized to the nucleus upon stimulation that results in reactivation. Here, chromatin immunoprecipitation assays demonstrate that HCF-1 is recruited to IE promoters of viral genomes during the initiation of reactivation, correlating with RNA polymerase II occupancy and IE expression. The data support the model whereby HCF-1 plays a pivotal role in the reactivation of HSV-1 from latency.


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