Viral Membranes

Many viruses are surrounded by a continuous bilayer membrane studded with viral proteins. Its purpose is to protect the genome-containing virus nucleocapsid from damage, and to facilitate entry of the nucleocapsid into a host cell. Viral membrane proteins attach the virus to the host cell, and promote fusion between viral and host cell membranes. Enveloped viruses form by a budding process, involving the wrapping up of newly synthesized nucleocapsids with regions of host cell membranes containing host cell lipids but exclusively viral proteins. Host cell machinery and processes are co-opted by enveloped viruses for use at every stage of these viral events.