Newcastle Disease Virus Fusion glycoprotein F1; NDV Glycoprotein F1

The F1 subunit is one of two subunits (along with F2) that form the active Fusion (F) protein of Newcastle Disease Virus (NDV), a highly contagious avian paramyxovirus. The F protein is crucial for the virus's ability to enter host cells. Synthesized as an inactive precursor F0, it must be cleaved by host cell proteases into the disulfide-linked F1 and F2 subunits to become functional. The F1 subunit contains the fusion peptide, a hydrophobic sequence at its N-terminus that inserts into the host cell membrane, initiating the fusion process between the viral envelope and the host cell membrane, ultimately allowing the release of the viral nucleocapsid into the cytoplasm.