Faculty Collaboration Database

Structure/Function analysis of the vaccinia virus F18 phosphoprotein, an abundant core component required for virion maturation and infectivity. J Virol 2010 Jul;84(13):6846-60

Date

04/16/2010

Pubmed ID

20392848

Pubmed Central ID

PMC2903294

DOI

10.1128/JVI.00399-10

Scopus ID

2-s2.0-77953307473 (requires institutional sign-in at Scopus site)   20 Citations

Abstract

Poxvirus virions, whose outer membrane surrounds two lateral bodies and a core, contain at least 70 different proteins. The F18 phosphoprotein is one of the most abundant core components and is essential for the assembly of mature virions. We report here the results of a structure/function analysis in which the role of conserved cysteine residues, clusters of charged amino acids and clusters of hydrophobic/aromatic amino acids have been assessed. Taking advantage of a recombinant virus in which F18 expression is IPTG (isopropyl-beta-d-thiogalactopyranoside) dependent, we developed a transient complementation assay to evaluate the ability of mutant alleles of F18 to support virion morphogenesis and/or to restore the production of infectious virus. We have also examined protein-protein interactions, comparing the ability of mutant and WT F18 proteins to interact with WT F18 and to interact with the viral A30 protein, another essential core component. We show that F18 associates with an A30-containing multiprotein complex in vivo in a manner that depends upon clusters of hydrophobic/aromatic residues in the N' terminus of the F18 protein but that it is not required for the assembly of this complex. Finally, we confirmed that two PSSP motifs within F18 are the sites of phosphorylation by cellular proline-directed kinases in vitro and in vivo. Mutation of both of these phosphorylation sites has no apparent impact on virion morphogenesis but leads to the assembly of virions with significantly reduced infectivity.

Author List

Wickramasekera NT, Traktman P

MESH terms used to index this publication - Major topics in bold

Animals
Cell Line
DNA Mutational Analysis
Genetic Complementation Test
Microscopy, Electron, Transmission
Mutant Proteins
Phosphoproteins
Phosphorylation
Protein Binding
Protein Interaction Mapping
Protein Processing, Post-Translational
Vaccinia virus
Viral Proteins
Virion
Virus Assembly