@article{mbs:/content/journal/jgv/10.1099/0022-1317-82-6-1375, author = "Sugrue, Richard J. and Brown, Craig and Brown, Gaie and Aitken, James and McL. Rixon, Helen W.", title = "Furin cleavage of the respiratory syncytial virus fusion protein is not a requirement for its transport to the surface of virus-infected cells", journal= "Journal of General Virology", year = "2001", volume = "82", number = "6", pages = "1375-1386", doi = "https://doi.org/10.1099/0022-1317-82-6-1375", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-82-6-1375", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "The intracellular cleavage of respiratory syncytial virus (RSV) fusion (F) protein by furin was examined. In RSV-infected LoVo cells, which express an inactive form of furin, and in RSV-infected Vero cells treated with the furin inhibitor decanoyl-Arg-Val-Lys-Arg-chloromethyl ketone (dec-RVKR-cmk), the F protein was expressed as a non-cleaved 73 kDa species. In both cases the F protein was initially expressed as an endoglycosidase H (Endo H)-sensitive precursor (F0EHs) which was modified approximately 40 min post-synthesis by the addition of complex carbohydrates to produce the Endo H-resistant form (F0EHr). The size and glycosylation state of F0EHr were identical to a transient intermediate form of non-cleaved F protein which was detected in RSV-infected Vero cells in the absence of inhibitor. Cell surface biotinylation and surface immunofluorescence staining showed that F0EHr was present on the surface of RSV-infected cells. RSV filaments have been shown to be the predominant form of the budding virus that is detected during virus replication. Analysis of the RSV-infected cells using scanning electron microscopy (SEM) showed that, in the presence of dec-RVKR-cmk, virus budding was impaired, producing fewer and much smaller viral filaments than in untreated cells. A comparison of immunofluorescence and SEM data showed that F0EHr was routed to the surface of virus-infected cells but not located in these smaller structures. Our findings suggest that activation of the F protein is required for the efficient formation of RSV filaments.", }