An E2-F12 complex is required for intracellular enveloped virus morphogenesis during vaccinia infection.
The vaccinia virus protein, F12, has been suggested to play an important role in microtubule-based transport of intracellular enveloped virus (IEV). We found that GFP-F12 is recruited to IEV moving on microtubules but is released from virus particles when they switch to actin-based motility. In the absence of F12, although the majority of IEV remain close to their peri-nuclear site of assembly, a small number of IEV still move with linear trajectories at speeds of 0.85 μm s(-1) , consistent with microtubule transport. Using a recombinant virus expressing GST-F12, we found that the viral protein E2 interacts directly with F12. In infected cells, GFP-E2 is observed on moving IEV as well as in the Golgi region, but is not associated with actin tails. In the absence of E2L, IEV accumulate in the peri-nuclear region and F12 is not recruited. Conversely, GFP-E2 is not observed on IEV in the absence of F12. Ultra-structural analysis of ΔE2L- and ΔF12L-infected cells reveals that loss of either protein results in defects in membrane wrapping during IEV formation. We suggest that E2 and F12 function as a complex that is necessary for IEV morphogenesis prior to their microtubule-based transport towards the plasma membrane.
Dodding
Mark P
MP
Cell Motility Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London, UK.
Newsome
Timothy P
TP
Collinson
Lucy M
LM
Edwards
Ceri
C
Way
Michael
M
D002460:Cell Line; D049452:Green Fluorescent Proteins / Q000032:analysis; D006801:Humans; D008870:Microtubules / Q000378:metabolism; D021381:Protein Transport; D014616:Vaccinia virus / Q000378:metabolism / Q000502:physiology*; D014764:Viral Proteins / Q000032:analysis / Q000378:metabolism*; D014771:Virion / Q000378:metabolism
D014764:Viral Proteins; D049452:Green Fluorescent Proteins