Functional characterization of human respiratory syncytial virus (hRSV) small hydrophobic protein (SH) through small interfering RNA (siRNA) that targets SH.

Abstract

Small hydrophobic (SH) protein is a transmembrane protein from Human Respiratory Syncytial Virus (hRSV). Though its gene sequence is highly conserved in clinical isolates, the function remains debatable in viral pathogenesis and replication. In this study, small interfering RNA (siRNA) targeting SH was employed to examine the effect of SH gene silencing and protein knockdown to other viral proteins – Fusion (F), Attachment (G) protein and Phosphopeotein (P) during viral pathogenesis in Hep-2 cell line. SH knockdown did not noticeably affect virus replication or result in a significant change in the distribution of viral proteins. However, subtle changes in the level of surface biotinylated F and G were observed in SH siRNA- treated sample. While immunoprecipitation using SH antibody showed a slight decrease of cross-linked surface G protein upon SH knockdown, SH knockdown however did not abolish the G proteins surface assembly, suggesting that SH may be involved indirectly in the process of a subpopulations SH-G complex formation on the surface of RSV-infected cells. SH seems to be dispensable for virus growth in tissue culture and further study is required to elucidate the function of SH during host-virus interaction.