Quantitative Proteomic Analysis of A549 Cells Infected with Human Respiratory Syncytial Virus

Munday, Diane C.; Emmott, Edward; Surtees, Rebecca; Lardeau, Charles-Hugues; Wu, Weining; Duprex, W. Paul; Dove, Brian K.; Barr, John N.; Hiscox, Julian A.

Because of their similar genome organization and gene expression strategy, the paramyxoviruses have been grouped into the Mononegavirales order that includes rabies and Ebola viruses (6) . HRSV has a cytoplasmic replication strategy, and the genome consists of a single-stranded negative sense RNA with the gene order 3Ј to 5Ј: non-structural protein 1 (NS1), non-structural protein 2 (NS2), nucleo-(N) protein, phospho-(P) protein, matrix (M) protein, small hydrophobic (SH) protein, glyco-(G) protein, fusion (F) protein, M2-1 and M2-2, and the large (L) protein. The viral proteins can be grouped into different functional categories. Four proteins are present in the viral envelope: the G, F, M, and SH proteins. The G protein plays a role in virus attachment (7) , and the F protein promotes virus penetration and fusion of infected cells (8) . The M protein is present in the inner viral membrane, is involved in virion morphogenesis, and traffics between the cytoplasm and the nucleus (9) . The SH protein is important to viral infectivity and is a potential viroporin (10) . Five proteins are involved in RNA synthesis and formation of the ribonucleocapsid structure: N and P proteins, M2-1, M2-2, and the L protein (11) (12) (13) (14) . The L protein is the catalytic component of the replicase-transcriptase complex and possesses RNA-dependent RNA polymerase activity. NS1 and NS2 are accessory proteins involved in modulating the host response to infection by acting as antagonists of the ␣/␤ interferon (IFN)mediated antiviral state (15) (16) (17) .