Data from: Coordination of the host Vps4-Vta1 complex and the viral core protein Ac93 facilitates entry of Autographa californica multiple nucleopolyhedrovirus budded virions

The endosomal sorting complex required for transport (ESCRT) is a protein
machine mediating membrane scission. In intraluminal vesicles (ILVs)
formation, ESCRT-0 targets cargoes and recruits ESCRT-I/-II to create
membrane invagination, whereas ESCRT-III coordinates with the AAA ATPase
Vps4 and its cofactor Vta1 to catalyze the membrane fission. Recently,
ESCRT-I/-III and Vps4 were found to involve in entry of the baculovirus
Autographa californica multiple nucleopolyhedrovirus (AcMNPV). However,
the necessity of other ESCRT components and the interplay of viral
proteins and ESCRTs in regulating the virus entry remain elusive. Here, we
identified ESCRT-0 (Hse1 and Vps27), ESCRT-II (Vps22, Vps25, and Vps36),
and Vta1 of S. frugiperda. RNAi depletion of Vta1 but not the components
of ESCRT-0 or ESCRT-II in Sf9 cells significantly reduced budded virus
(BV) production. Quantitative PCR together with confocal microscopy
analyses indicated that Vta1 was required for internalization and
endosomal trafficking of BV. In the late phase of infection, although Vps4
and Vta1 were both distributed to the nucleus and at the plasma membrane,
depletion of Vta1 did not affect BV release. Further analysis revealed
that 7 of 14 BV envelope proteins (Ac75, Ac93, E25, F-like, P33, P48, and
vUbiquitin) interacted with Vps4 and Vta1. Intriguingly, Ac93 adopted a
similar mode as ESCRT-III proteins to interact with the MIT domains of
Vps4 and Vta1 via its C-terminal MIM1 motif, and the interactions were
necessary for BV internalization. Together, our studies highlight the
coordination of Vps4-Vta1 and Ac93, and probably other BV envelope
proteins, in facilitating entry of AcMNPV.