Abstract
Cellular protein eukaryotic translation elongation factor 1A (eEF1A) is an actin binding protein that plays a role in the formation of filamentous actin (F-actin) bundles. F-Actin regulates multiple stages of respiratory syncytial virus (RSV) replication including assembly and budding. Our previous study demonstrated that eEF1A knock-down significantly reduced RSV replication. Here we investigated if the eEF1A function in actin bundle formation was important for RSV replication and release. To investigate this, eEF1A function was impaired in HEp-2 cells by either knock-down of eEF1A with siRNA, or treatment with an eEF1A inhibitor, didemnin B (Did B). Cell staining and confocal microscopy analysis showed that both eEF1A knock-down and treatment with Did B resulted in disruption of cellular stress fiber formation and elevated accumulation of F-actin near the plasma membrane. When treated cells were then infected with RSV, there was also reduced formation of virus-induced cellular filopodia. Did B treatment, similarly to eEF1A knock-down, reduced the release of infectious RSV, but unlike eEF1A knock-down, did not significantly affect RSV genome replication. The lower infectious virus production in Did B treated cells also reduced RSV-induced cell death. In conclusion, the cellular factor eEF1A plays an important role in the regulation of F-actin stress fiber formation required for RSV assembly and release.
Highlights
Human respiratory syncytial virus (RSV) is recognised globally as the main cause of acute lower respiratory infection in young children
Results eukaryotic translation elongation factor 1A (eEF1A) knock-down disrupted actin stress fiber formation and reduced RSV egress We previously demonstrated that eEF1A knock-down reduces RSV replication and subsequent shed virus [8]
Considering the role of actin in RSV trafficking and assembly [20] and the association between actin and eEF1A [21], here we examined if reduced infectious RSV release associated with knockdown of eEF1A is associated with actin structure changes
Summary
Human respiratory syncytial virus (RSV) is recognised globally as the main cause of acute lower respiratory infection in young children. Several RNA viruses including RSV have subverted cellular eEF1A for viral replication and. One of the alternative functions of eEF1A is as an actin binding protein that can regulate actin stress fiber formation in a Rho/Rho kinase pathway dependent. RSV requires actin for virus replication, and F-actin is reported to be important for viral transcription and morphogenesis. This is dependent on cellular profilin activity, which regulates F-actin formation in cells [12]. Further analysis showed that ARP2 supported viral spread during filopodia formation that could shuttle virus from infected to uninfected cells [14, 15]. Given the association between eEF1A and actin, and the dependence of RSV on actin for virus replication, we investigated whether the reduced RSV replication by down-regulated eEF1A, as we have reported previously [8] was, in part, due to the effect of change in actin filament structure, in addition to the effect on RSV genome replication
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
