This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Google Scholar
Right arrow Articles by Stropes, M. P.
Right arrow Articles by Miller, W. E.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Stropes, M. P.
Right arrow Articles by Miller, W. E.

 Previous Article  |  Next Article 

Journal of Virology, October 2009, p. 10016-10027, Vol. 83, No. 19
0022-538X/09/$08.00+0     doi:10.1128/JVI.00354-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

The Carboxy-Terminal Tail of Human Cytomegalovirus (HCMV) US28 Regulates both Chemokine-Independent and Chemokine-Dependent Signaling in HCMV-Infected Cells{triangledown} ,{dagger}

Melissa P. Stropes, Olivia D. Schneider, William A. Zagorski, Jeanette L. C. Miller, and William E. Miller*

Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0524

Received 17 February 2009/ Accepted 6 July 2009

The human cytomegalovirus (HCMV)-encoded G-protein-coupled receptor (GPCR) US28 is a potent activator of a number of signaling pathways in HCMV-infected cells. The intracellular carboxy-terminal domain of US28 contains residues critical for the regulation of US28 signaling in heterologous expression systems; however, the role that this domain plays during HCMV infection remains unknown. For this study, we constructed an HCMV recombinant virus encoding a carboxy-terminal domain truncation mutant of US28, FLAG-US28/1-314, to investigate the role that this domain plays in US28 signaling. We demonstrate that US28/1-314 exhibits a more potent phospholipase C-β (PLC-β) signal than does wild-type US28, indicating that the carboxy-terminal domain plays an important role in regulating agonist-independent signaling in infected cells. Moreover, HMCV-infected cells expressing the US28/1-314 mutant exhibit a prolonged calcium signal in response to CCL5, indicating that the US28 carboxy-terminal domain also regulates agonist-dependent signaling. Finally, while the chemokine CX3CL1 behaves as an inverse agonist or inhibitor of constitutive US28 signaling to PLC-β, we demonstrate that CX3CL1 functions as an agonist with regard to US28-stimulated calcium release. This study is the first to demonstrate that the carboxy terminus of US28 controls US28 signaling in the context of HCMV infection and indicates that chemokines such as CX3CL1 can decrease constitutive US28 signals and yet simultaneously promote nonconstitutive US28 signals.

* Corresponding author. Mailing address: Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0524. Phone: (513) 558-0866. Fax: (513) 558-8474. E-mail: william.miller{at}uc.edu

{triangledown} Published ahead of print on 15 July 2009.

{dagger} Supplemental material for this article may be found at http://jvi.asm.org/.

Journal of Virology, October 2009, p. 10016-10027, Vol. 83, No. 19
0022-538X/09/$08.00+0     doi:10.1128/JVI.00354-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»