Fig. 5.

mda-5 activity is inhibited by the C terminus of SV5 V and is a property of other paramyxovirus V proteins. Vero cells were cotransfected with the IFN-β luciferase reporter, the β-galactosidase expression vector, pJATlacZ, and mammalian expression plasmids driving the overexpression of mda-5 or the control “empty vector,” and either the V or P proteins of SV5 or truncations of the SV5 V protein (a) or the V proteins of other paramyxoviruses (b). In each case, luciferase activity was corrected to the β-galactosidase activity to normalize for variations in the transfection efficiency. Transfection experiments were repeated at least twice, and averages and error bars are shown. Expression levels are compared with the basal level of the empty vector (=1) in each case.