Mutagenesis of Varicella-Zoster Virus Glycoprotein I (gI) Identifies a Cysteine Residue Critical for gE/gI Heterodimer Formation, gI Structure, and Virulence in Skin Cells
Autor: | James L. Zehnder, Jason Chia-Hsien Cheng, Leonssia Vlaycheva-Beisheim, Carol D. Jones, Jaya Rajamani, Shaye Stamatis, Mike Reichelt, Stefan L. Oliver, Marvin Sommer, Ann M. Arvin |
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Rok vydání: | 2011 |
Předmět: |
Herpesvirus 3
Human Virulence Factors viruses DNA Mutational Analysis Immunology Mutant Mutagenesis (molecular biology technique) Virulence Viral Plaque Assay Virus Replication medicine.disease_cause Microbiology Virus Cell Line Viral Envelope Proteins Virology Alphaherpesvirinae parasitic diseases Protein Interaction Mapping medicine Humans Cysteine Sequence Deletion Skin chemistry.chemical_classification biology Varicella zoster virus virus diseases biology.organism_classification Molecular biology Amino Acid Substitution Viral replication chemistry Insect Science population characteristics Pathogenesis and Immunity Protein Multimerization Glycoprotein human activities |
Zdroj: | Journal of Virology. 85:4095-4110 |
ISSN: | 1098-5514 0022-538X |
Popis: | Varicella-zoster virus (VZV) is the alphaherpesvirus that causes chicken pox (varicella) and shingles (zoster). The two VZV glycoproteins gE and gI form a heterodimer that mediates efficient cell-to-cell spread. Deletion of gI yields a small-plaque-phenotype virus, ΔgI virus, which is avirulent in human skin using the xenograft model of VZV pathogenesis. In the present study, 10 mutant viruses were generated to determine which residues were required for the typical function of gI. Three phosphorylation sites in the cytoplasmic domain of gI were not required for VZV virulence in vivo . Two deletion mutants mapped a gE binding region in gI to residues 105 to 125. A glycosylation site, N116, in this region did not affect virulence. Substitution of four cysteine residues highly conserved in the Alphaherpesvirinae established that C95 is required for gE/gI heterodimer formation. The C95A and Δ105–125 (with residues 105 to 125 deleted) viruses had small-plaque phenotypes with reduced replication kinetics in vitro similar to those of the ΔgI virus. The Δ105–125 virus was avirulent for human skin in vivo . In contrast, the C95A mutant replicated in vivo but with significantly reduced kinetics compared to those of the wild-type virus. In addition to abolished gE/gI heterodimer formation, gI from the C95A or the Δ105–125 mutant was not recognized by monoclonal antibodies that detect the canonical conformation of gI, demonstrating structural disruption of gI in these viruses. This alteration prevented gI incorporation into virus particles. Thus, residues C95 and 105 to 125 are critical for gI structure required for gE/gI heterodimer formation, virion incorporation, and ultimately, effective viral spread in human skin. |
Databáze: | OpenAIRE |
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