FIG. 3.

Egress of VV particles from cells on actin tails. Poxvirus nucleocapsids are formed and acquire envelopes in virus factories, producing IMV, which subsequently acquire two additional membranes by budding into the TGN, forming IEV. Microtubules are involved in the transport of IMV and IEV to the plasma membrane (PM). There is fusion of the outer envelope with the plasma membrane, and CEV (bound to the cell surface) rest on platforms, composed in part of A33R, A34R, and A36R, that sit at one pole of the virus particle. A36R promotes the nucleation of actin filaments through interactions with Nck and recruitment of WIP, N-WASP, and Arp2/3 (inset), leading to actin polymerization. Actin tails produce microvilli that project CEV toward adjacent cells, promoting virus entry.