Abstract:
The subcellular localization of the minor nonstructural protein NS3 of African horsesickness virus (AHSV)
has been investigated by means of immunogold electron-microscopical analysis. NS3 was observed
in perturbed regions of the plasma membrane of AHSV-infected VERO cells, and its presence appears
to be associated with events of viral release. These events are budding, whereby released viruses
acquire fragments from the host-cell membrane, as well as by the extrusion of nonenveloped particles
through the cell membrane. The membrane association of NS3 was confirmed by its detection in the
disrupted plasma membranes of cells infected with an NS3 baculovirus recombinant. The absence of
NS3 on intact cell membranes suggests that the protein is not exposed extracellularly.
