CONTEXT

Viral fusion proteins are transmembrane glycoproteins implicated in the early stages of the viral cycle of enveloped viruses. These glycoproteins are involved in the merging and consecutive fusion between the viral envelope and the targeted cell membrane. In later stages of viral cycle, these viral glycoproteins are expressed at the viral surface of infected cells and trigger the fusion with adjacent cells, forming giant muntinucleated cells (syncytia).

We investigated the effect of 20 different combinations of 12 amino-acid substitutions within functional domains of the parainfluenza virus type 5 (PIV-5) F glycoprotein, by performing cell surface expression measurements, quantitative fusion and syncytia assays (Terrier et al. 2009). We found that combinations of mutations conferring an autonomous phenotype with mutations leading to an increased fusion activity were compatible and generated functional PIV-5 F proteins.

Reference : Terrier O, Durupt F, Cartet G, Thomas L, Lina B, Rosa-Calatrava M. Engineering of a parainfluenza virus type 5 fusion protein (PIV-5 F): development of an autonomous and hyperfusogenic protein by a combinational mutagenesis approach. Virus Res. 2009 Dec;146(1-2):115-24.