Illuminating the Sites of Enterovirus Replication in Living Cells by Using a Split-GFP-Tagged Viral Protein

van der Schaar, H. M.; Melia, C. E.; van Bruggen, J. A. C.; Strating, J. R. P. M.; van Geenen, M. E. D.; Koster, A. J.; Bárcena, M.; van Kuppeveld, F. J. M.

The enterovirus 3A protein interacts directly with GBF1, an essential host factor for enterovirus replication (27, 30) . Under normal conditions, GBF1 is an activator of the small GTPase Arf1, which in turn recruits the COP-I complex to Golgi membranes upon activation (40) . The COP-I coat initiates budding of transport vesicles that ferry cargo at the ER-Golgi interface and in the Golgi apparatus (41) . Expression of 3A in isolation leads to the perturbation of ER-to-Golgi transport (30, (42) (43) (44) , as demonstrated by the dissociation of COP-I from Golgi membranes in BGM cells (44) , presumably as a result of the interaction of 3A with GBF1 (30, 44) . Similar to untagged 3A, 3A(S11aa2) visualized by coexpression of GFP(S1-10) clearly caused COP-I dissociation (Fig. 1C ).