A I131V Substitution in the Fusion Glycoprotein of Human Parainfluenza Virus Type 1 Enhances Syncytium Formation and Virus Growth.

A I131V Substitution in the Fusion Glycoprotein of Human Parainfluenza Virus Type 1 Enhances Syncytium Formation and Virus Growth. Biol Pharm Bull. 2019;42(5):827-832 Authors: Fukushima K, Takahashi T, Takaguchi M, Ito S, Suzuki C, Agarikuchi T, Kurebayashi Y, Minami A, Suzuki T Abstract Human parainfluenza virus type 1 (hPIV1) has two spike glycoproteins, the hemagglutinin-neuraminidase (HN) glycoprotein as a receptor-binding protein and the fusion (F) glycoprotein as a membrane-fusion protein. The F glycoprotein mediates both membrane fusion between the virus and cell and membrane fusion between cells, called syncytium formation. Wild-type C35 strain (WT) of hPIV1 shows little syncytium formation of infected cells during virus growth. In the present study, we isolated a variant virus (Vr) from the WT that showed enhanced syncytium formation of infected cells by using our previously established hPIV1 plaque formation assay. Vr formed a larger focus and showed increased virus growth compared with WT. Sequence analysis of the spike glycoprotein genes showed that the Vr had a single amino acid substitution of Ile to Val at position 131 in the fusion peptide region of the F glycoprotein without any substitutions of the HN glycoprotein. The Vr F glycoprotein showed enhanced syncytium formation in F and HN glycoprotein-expressing cells. Additionally, expression of the Vr F glycoprotein increased the focus area of the WT-infected cells. Th...
Source: Biological and Pharmaceutical Bulletin - Category: Drugs & Pharmacology Authors: Tags: Biol Pharm Bull Source Type: research