Binding of Viral Glycoprotein mRNA to Endoplasmic Reticulum Membranes Is Disrupted by Puromycin

Previous studies showed that the glycoprotein (G) of vesicular stomatitis virus is synthesized in association with the endoplasmic reticulum (ER) membrane and that all G mRNA co-fractionates with ER membrane. Here, we show that treatment of infected cells with puromycin results in dissociation of G mRNA, and presumably the associated ribosomes, from the ER membrane. Even if extracts from treated cells are kept at low ionic strength (0.01 M KCl), over 80% of G mRNA is found unattached to membranes. There is no evidence for direct interaction of G mRNA with membranes; rather, the linkage apparently is mediated by the nascent G polypeptide.