Human cytomegalovirus (HCMV) causes substantial morbidity and mortality, primarily in newborns and immunocompromised patients. Like other viruses, HCMV must evade myriad host cell antiviral defense mechanisms, among which is the shut off of overall protein synthesis mediated by the interferon-induced, double-stranded RNA (dsRNA)-activated protein kinase R (PKR). HCMV encodes two proteins, pTRS1 and pIRS1, that block PKR activation. In addition to self-associating and to binding to dsRNA and to PKR, these proteins have the unprecedented effect of causing PKR to relocalize to the nucleus. In order to elucidate the mechanism and significance of pTRS1 and pIRS1 effects on PKR, experiments are proposed to precisely delineate the domains of pTRS1 and pIRS1 responsible for their interactions with RNA and proteins. These studies will also reveal whether the nuclear relocalization of PKR by pTRS1 and pIRS1 serves as an unusual viral strategy for removing PKR from its cytoplasmic targets or as a means of facilitating an as-yet-unidentified nuclear function of PKR that may be beneficial to the virus. Finally, experiments will directly test the hypothesis that either pTRS1 or pIRS1, and in particular their ability to bind to dsRNA and PKR, is essential for HCMV replication. Understanding the mechanism by which HCMV interferes with the PKR pathway will contribute new perspectives into biochemical interactions required for PKR inhibition in other systems as well as insights into the significance of the PKR nuclear redistribution activity which thus far seems to be a unique property of betaherpeviruses. The insights gained from studies of these unconventional HCMV dsRNA-binding proteins will also contribute to identifying new dsRNA-binding proteins in other systems and for analyzing their functions in counteracting PKR and other dsRNA-activated responses. Finally, since mutant viruses lacking the ability to block PKR activation have greatly reduced virulence in animal models, results of these studies may have applications in the development of new antiviral strategies and for the development of live attenuated vaccines.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI026672-23
Application #
8239916
Study Section
Special Emphasis Panel (ZRG1-IDM-M (04))
Program Officer
Beisel, Christopher E
Project Start
1988-08-01
Project End
2013-05-31
Budget Start
2012-04-01
Budget End
2013-05-31
Support Year
23
Fiscal Year
2012
Total Cost
$423,338
Indirect Cost
$178,313
Name
Fred Hutchinson Cancer Research Center
Department
Type
DUNS #
078200995
City
Seattle
State
WA
Country
United States
Zip Code
98109
Carpentier, Kathryn S; Geballe, Adam P (2016) An Evolutionary View of the Arms Race between Protein Kinase R and Large DNA Viruses. J Virol 90:3280-3
Mouna, Lina; Hernandez, Eva; Bonte, Dorine et al. (2016) Analysis of the role of autophagy inhibition by two complementary human cytomegalovirus BECN1/Beclin 1-binding proteins. Autophagy 12:327-42
Daugherty, Matthew D; Schaller, Aaron M; Geballe, Adam P et al. (2016) Evolution-guided functional analyses reveal diverse antiviral specificities encoded by IFIT1 genes in mammals. Elife 5:
Braggin, Jacquelyn E; Child, Stephanie J; Geballe, Adam P (2016) Essential role of protein kinase R antagonism by TRS1 in human cytomegalovirus replication. Virology 489:75-85
Gray, Elizabeth E; Winship, Damion; Snyder, Jessica M et al. (2016) The AIM2-like Receptors Are Dispensable for the Interferon Response to Intracellular DNA. Immunity 45:255-66
Brennan, Greg; Kitzman, Jacob O; Shendure, Jay et al. (2015) Experimental Evolution Identifies Vaccinia Virus Mutations in A24R and A35R That Antagonize the Protein Kinase R Pathway and Accompany Collapse of an Extragenic Gene Amplification. J Virol 89:9986-97
Brennan, Greg; Kitzman, Jacob O; Rothenburg, Stefan et al. (2014) Adaptive gene amplification as an intermediate step in the expansion of virus host range. PLoS Pathog 10:e1004002
Bierle, Craig J; Semmens, Kathryn M; Geballe, Adam P (2013) Double-stranded RNA binding by the human cytomegalovirus PKR antagonist TRS1. Virology 442:28-37
Elde, Nels C; Child, Stephanie J; Eickbush, Michael T et al. (2012) Poxviruses deploy genomic accordions to adapt rapidly against host antiviral defenses. Cell 150:831-41
Bierle, Craig J; Schleiss, Mark R; Geballe, Adam P (2012) Antagonism of the protein kinase R pathway by the guinea pig cytomegalovirus US22-family gene gp145. Virology 433:157-66

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