CERULENIN INHIBITS PRODUCTION OF MATURE VIRION PARTICLES IN CHICK-EMBRYO FIBROBLASTS INFECTED BY INFLUENZA-A VIRUSES

We investigated acylation of haemagglutinin (HA) of type A influenza v iruses during infection of permissive chick embryo fibroblasts (CEF) t reated with cerulenin. Fatty acid binding was monitored using a mainte nance medium containing H-3-palmitic acid. Our results suggest that fa tty acid acylation of viral haemagglutinin may be essential for produc tion of mature viral particles. Indeed, palmitoylation was found in in fected CEF cells, but was lacking during the infectious cycle when cel ls were treated with a dose of 30 mu g/ml of cerulenin. We discuss the possibility that acylation of virus-induced HA is a posttranslational modification regulating correct insertion of virus haemagglutinin int o the cellular membrane and, as a consequence, controlling the maturat ion of budding influenza virus.