Synchronised transmembrane insertion and glycosylation of a nascent membrane protein.

Studies of the synthesis and incorporation of the vesicular stomatitis virus glycoprotein into membranes in a synchronised cell-free system demonstrate a tight coupling between polypeptide synthesis and membrane insertion, as a result of which the nascent chain crosses the membrane. The studies reveal a surprisingly precise sequence by which the nascent chain of this membrane glycoprotein is glycosylated in two steps. These findings have important implications for the mechanisms of membrane assembly.