Role of acylation of viral haemagglutinin during the influenza virus infectious cycle.

We investigated fatty acid residues bound to the haemagglutinin (HA) of type A influenza viruses by growing the viruses in permissive chick embryo fibroblasts (CEF) and in non-permissive HeLa-229 cells using a maintenance medium containing 3H-palmitic acid. Our results suggest that fatty acid acylation of the major viral glycoprotein may be an important prerequisite for the production of mature viral particles. Indeed, palmitoylation is found in infected CEF, but is completely lacking in non-permissive HeLa-229 cells infected by the same virus strains. We conclude that this type of post-translational modification of virus HA glycoprotein could be a general phenomenon regulating the maturation and budding of influenza virus.