This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Altamura, L. A. Articles by Doms, R. W. Search for Related Content PubMed PubMed Citation Articles by Altamura, L. A. Articles by Doms, R. W.

 Previous Article  |  Next Article 

Journal of Virology, June 2007, p. 6632-6642, Vol. 81, No. 12
0022-538X/07/$08.00+0     doi:10.1128/JVI.02730-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Identification of a Novel C-Terminal Cleavage of Crimean-Congo Hemorrhagic Fever Virus PreG_N That Leads to Generation of an NS_M Protein

Louis A. Altamura,¹ Andrea Bertolotti-Ciarlet,¹ Jeffrey Teigler,² Jason Paragas,^3, Connie S. Schmaljohn,³ and Robert W. Doms^1*

Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104,¹ Ursinus College, Collegeville, Pennsylvania 19426,² United States Army Medical Research Institute for Infectious Diseases, Fort Detrick, Frederick, Maryland 21702³

Received 12 December 2006/ Accepted 29 March 2007

The structural glycoproteins of Crimean-Congo hemorrhagic fever virus (CCHFV; genus Nairovirus, family Bunyaviridae) are derived through endoproteolytic cleavage of a 1,684-amino-acid M RNA segment-encoded polyprotein. This polyprotein is cotranslationally cleaved into the PreG_N and PreG_C precursors, which are then cleaved by SKI-1 and a SKI-1-like protease to generate the N termini of G_N and G_C, respectively. However, the resulting polypeptide defined by the N termini of G_N and G_C is predicted to be larger (58 kDa) than mature G_N (37 kDa). By analogy to the topologically similar M segment-encoded polyproteins of viruses in the Orthobunyavirus genus, the C-terminal region of PreG_N that contains four predicted transmembrane domains may also contain a nonstructural protein, NS_M. To characterize potential PreG_N C-terminal cleavage events, a panel of epitope-tagged PreG_N truncation and internal deletion mutants was developed. These constructs allowed for the identification of a C-terminal endoproteolytic cleavage within, or very proximal to, the second predicted transmembrane domain following the G_N ectodomain and the subsequent generation of a C-terminal fragment. Pulse-chase experiments showed that PreG_N C-terminal cleavage occurred shortly after synthesis of the precursor and prior to generation of the G_N glycoprotein. The resulting fragment trafficked to the Golgi compartment, the site of virus assembly. Development of an antiserum specific to the second cytoplasmic loop of PreG_N allowed detection of cell-associated NS_M proteins derived from transient expression of the complete CCHFV M segment and also in the context of virus infection.

---

* Corresponding author. Mailing address: Department of Microbiology, University of Pennsylvania, 225 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104. Phone: (215) 898-0890. Fax: (215) 898-9557. E-mail: doms{at}mail.med.upenn.edu

Published ahead of print on 11 April 2007.

Present address: National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.

---

Journal of Virology, June 2007, p. 6632-6642, Vol. 81, No. 12
0022-538X/07/$08.00+0     doi:10.1128/JVI.02730-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

This article has been cited by other articles:

• Bergeron, E., Vincent, M. J., Nichol, S. T. (2007). Crimean-Congo Hemorrhagic Fever Virus Glycoprotein Processing by the Endoprotease SKI-1/S1P Is Critical for Virus Infectivity. J. Virol. 81: 13271-13276 [Abstract] [Full Text]