Identification des partenaires de gM du virus VHS-1 par BioID couplée à la spectrométrie de masse
Among the glycoproteins of HSV-1, glycoprotein M (gM) regulates the fusion between the envelope of the virus and the plasma membrane. gM is the first one of the viral glycoproteins to be detected in the nuclear membrane early in the viral cycle at 4 h post infection. However, the mechanism by which it’s targeted to the nuclear membrane, as well as for the host’s proteins, is still unknown. The knowns partners of gM that have been previously described by yeast two-hybrid and co-immunoprecipitation do not appear to be involved in this targeting. Herein, we hypothesize that other viral and/or cellular proteins are involved. To investigate the likelihood of new gM partners, a BioID approach was used. Cell lines expressing gM coupled to BirA* and other control cell lines have been used and infected for 4 or 12 h with the ∆gM-2 HSV-1. The purified samples were then analyzed by mass spectrometry where 177 hits were identified. Among them, the proteins SNX1, SNX2, SCAMP3, VPS33B, MTMR6, TMEM43 and XPO6, all implicated in intracellular transport or in the integrity of the intern nuclear membrane, were chosen to validate their putative role in the delocalization of gM by siRNA. The target knockdowns were validated by RT-qPCR and further confirmed using immunofluorescence. Eventually, these targets will be further studied to assess their role in viral egress using plaque assay. In the future, this study will deepen our understanding of the mechanism of viral egress and eventually might provide a new model that could explain how gM and host proteins are being targeted to the nuclear membranes.
herpes simplex virus type 1 (HSV-1) glycoprotein M (gM) nuclear membranes Biotin-Identification (BioID) mass spectrometry nuclear transport