Equine herpesvirus type 1 (EHV-1) glycoprotein K is required for efficient cell-to-cell spread and virus egress
- Institute for Medical Microbiology, Infectious and Epidemic Diseases, Ludwig-Maximilians-Universitaet Muenchen, D-80539 Munich (Germany)
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853 (United States)
The function of the equine herpesvirus type 1 (EHV-1) glycoprotein K (gK) homologue was investigated. Deletion of 88% of the UL53-homologous open reading frame in EHV-1 strain RacH resulted in a severe growth defect of the gK-negative virus (H{delta}gK) as reflected by a significant decrease in the production of infectious virus progeny on RK13 cells. The H{delta}gK virus induced only minute plaques, was unable to form syncytia, and its penetration efficiency into RK13 cells was reduced by approximately 40%. To further analyze gK function and intracellular trafficking, gK of strain RacH was replaced by a C-terminally truncated gK-green fluorescent protein fusion protein (gK-GFP). The generated recombinant virus was shown to replicate well on non-complementing cells, and virus penetration and syncytium formation were comparable to parental RacH. A reduction in plaque size and slightly decreased intra- and extracellular virus titers, however, were observed. The gK-GFP fusion protein was expressed with early-late kinetics, and multiple forms of the protein exhibiting M{sub r}s between 50,000 and 85,000 were detected by Western blot analysis. The various gK-GFP forms were shown to be N-glycosylated, associated with membranes of the Golgi apparatus, and were incorporated into extracellular virions. Complete processing of gK-GFP was only observed within the context of viral infection. From the results, we concluded that EHV-1 gK is required for efficient virus growth in vitro and that the carboxy-terminal amino acids are not required for its function, because the gK-GFP fusion protein was able to complement for EHV-1 growth in the absence of authentic gK.
- OSTI ID:
- 20637173
- Journal Information:
- Virology, Vol. 329, Issue 1; Other Information: DOI: 10.1016/j.virol.2004.07.034; PII: S0042-6822(04)00522-7; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0042-6822
- Country of Publication:
- United States
- Language:
- English
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