Document Detail

Entry of vaccinia virus and cell-cell fusion require a highly conserved cysteine-rich membrane protein encoded by the A16L gene.
MedLine Citation:
PMID:  16352530     Owner:  NLM     Status:  MEDLINE    
The vaccinia virus A16L open reading frame encodes a 378-amino-acid protein with a predicted C-terminal transmembrane domain and 20 invariant cysteine residues that is conserved in all sequenced members of the poxvirus family. The A16 protein was expressed late in infection and incorporated into intracellular virus particles with the N-terminal segment of the protein exposed on the surface. The cysteine residues were disulfide bonded via the poxvirus cytoplasmic redox system. Unsuccessful attempts to isolate a mutant virus with the A16L gene deleted suggested that the protein is essential for replication. To study the role of the A16 protein, we made a recombinant vaccinia virus that has the Escherichia coli lac operator system regulating transcription of the A16L gene. In the absence of inducer, A16 synthesis was repressed and plaque size and virus yield were greatly reduced. Nevertheless, virus morphogenesis occurred and normal-looking intracellular and extracellular virus particles formed. Purified virions made in the presence and absence of inducer were indistinguishable, though the latter had 60- to 100-fold-lower specific infectivity. A16-deficient virions bound to cells, but their cores did not penetrate into the cytoplasm. Furthermore, A16-deficient virions were unable to induce low-pH-triggered syncytium formation. The phenotype of the inducible A16L mutant was similar to those of mutants in which synthesis of the A21, A28, H2, or L5 membrane protein was repressed, indicating that at least five conserved viral proteins are required for entry of poxviruses into cells as well as for cell-cell fusion.
Suany Ojeda; Tatiana G Senkevich; Bernard Moss
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Intramural    
Journal Detail:
Title:  Journal of virology     Volume:  80     ISSN:  0022-538X     ISO Abbreviation:  J. Virol.     Publication Date:  2006 Jan 
Date Detail:
Created Date:  2005-12-14     Completed Date:  2007-01-26     Revised Date:  2013-06-07    
Medline Journal Info:
Nlm Unique ID:  0113724     Medline TA:  J Virol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  51-61     Citation Subset:  IM    
Laboratory of Viral Diseases, National Institutes of Health, 4 Center Dr., MSC 0445, Bethesda, MD 20892-0445, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Amino Acid Sequence
Cell Fusion
Cell Line
Membrane Fusion / drug effects,  physiology*
Molecular Sequence Data
Open Reading Frames
Vaccinia virus / genetics,  pathogenicity,  physiology*
Viral Fusion Proteins / chemistry,  genetics,  physiology*
Virus Replication
Reg. No./Substance:
0/A16L protein, vaccinia virus; 0/Viral Fusion Proteins; 52-90-4/Cysteine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Herpes simplex virus DNA synthesis is not a decisive regulatory event in the initiation of lytic vir...
Next Document:  Anti-CD45RO suppresses human immunodeficiency virus type 1 replication in microglia: role of Hck tyr...