ABSTRACT
Like other integral membrane proteins, the hemagglutinin (HA) as the major glycoprotein of the influenza virus envelope is translated at the rough endoplasmic reticulum and transported from there through the Golgi apparatus to the plasma membrane. An expression system was developed in insect cells using Autographa californica nuclear polyhedrosis virus (AcNPV) as a vector. The first membrane protein expressed by an AcNPV vector was the HA of influenza virus. Synthesis of the HA provides valuable information on the capacity of the system to exert the complex processing steps required for the biological function of such proteins. Cotransfection of Spodoptera frugiperda cells with DNA from AcNPV and a vector containing the HA gene of fowl plague virus, an avian influenza virus, was done essentially as described by Smith Kline and co-workers. Polyadenylated RNA was isolated from S. frugiperda cells infected with authentic virus, recombinant virus, or from mock infected cells, and analyzed by the Northern blotting technique.
