Biology Reference
In-Depth Information
Fig. 4.
Filamentous particles comprising VP40 and the lipid bilayer.
(
A
) Expression of VP40 in mammalian cells induces filamentous particles
similar to spikeless Ebola virions. (
B
) Ebola virus-like particles are formed by
coexpression of VP40 and GP.
trypsin-resistance assay. Electron microscopic studies of the virosomes
released from VP40-expressing cells also indicated that these particles
bore a strong resemblance to GP-minus (spikeless) filovirus particles
(Fig. 4a).
9,13
Removal of the carboxy-terminus of Ebola virus VP40
severely compromises the release of virus-like particles,
6
emphasizing
the importance of this region in budding. Collectively, these studies
have demonstrated that VP40 is the primary morphological determi-
nant in filovirus morphogenesis and that all of the information for
membrane association, self-assembly, filamentous particle formation,
and budding resides in the sequence of this protein.
For several viruses, their matrix proteins associate with the cyto-
plasmic tails of the viral envelope glycoproteins.
5
By the same token,
