Trichoplusia ni Kinesin-1 Associates with Autographa californica Multiple Nucleopolyhedrovirus Nucleocapsid Proteins and Is Required for Production of Budded Virus

Biswas, Siddhartha; Blissard, Gary W.; Theilmann, David A.

doi:10.1128/jvi.02912-15

Cited by 14 publications

(16 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the cytoplasm, the membranes of these vesicles (containing nucleocapsids) are lost by an unknown mechanism (25,68), and the nucleocapsids are subsequently transported to the plasma membrane, where they interact with the plasma membrane and bud to acquire an envelope, forming the budded virions (25). Egress of BV requires kinesin, suggesting that vesicles involved in nucleocapsid egress move along microtubules (69). Because of the importance of ESCRT-I and ESCRT-III components in AcMNPV entry, we could not use the same viral complementation system to study the role of these ESCRT factors in virus egress.…”

Section: Isolation and Expression Of Escrt-i And Escrt-iii Componentsmentioning

confidence: 99%

Distinct Roles of Cellular ESCRT-I and ESCRT-III Proteins in Efficient Entry and Egress of Budded Virions of Autographa californica Multiple Nucleopolyhedrovirus

Yang

et al. 2018

J Virol

Self Cite

View full text Add to dashboard Cite

The endosomal sorting complex required for transport (ESCRT) machinery is necessary for budding of many enveloped viruses. Recently, it was demonstrated that Vps4, the key regulator for recycling of the ESCRT-III complex, is required for efficient infection by the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV). However, ESCRT assembly, regulation, and function are complex, and little is known regarding the details of participation of specific ESCRT complexes in AcMNPV infection. In this study, the core components of ESCRT-I (Tsg101 and Vps28) and ESCRT-III (Vps2B, Vps20, Vps24, Snf7, Vps46, and Vps60) were cloned from Using a viral complementation system and RNA interference (RNAi) assays, we found that ESCRT-I and ESCRT-III complexes are required for efficient entry of AcMNPV into insect cells. In cells knocking down or overexpressing dominant negative (DN) forms of the components of ESCRT-I and ESCRT-III complexes, entering virions were partially trapped within the cytosol. To examine only egress, cells were transfected with the double-stranded RNA (dsRNA) targeting an individual ESCRT-I or ESCRT-III gene and viral bacmid DNA or viral bacmid DNA that expressed DN forms of ESCRT-I and ESCRT-III components. We found that ESCRT-III components (but not ESCRT-I components) are required for efficient nuclear egress of progeny nucleocapsids. In addition, we found that several baculovirus core or conserved proteins (Ac11, Ac76, Ac78, GP41, Ac93, Ac103, Ac142, and Ac146) interact with Vps4 and components of ESCRT-III. We propose that these viral proteins may form an "egress complex" that is involved in recruiting ESCRT-III components to a virus egress domain on the nuclear membrane. The ESCRT system is hijacked by many enveloped viruses to mediate budding and release. Recently, it was found that Vps4, the key regulator of the cellular ESCRT machinery, is necessary for efficient entry and egress of Autographa californica multiple nucleopolyhedrovirus (AcMNPV). However, little is known about the roles of specific ESCRT complexes in AcMNPV infection. In this study, we demonstrated that ESCRT-I and ESCRT-III complexes are required for efficient entry of AcMNPV into insect cells. The components of ESCRT-III (but not ESCRT-I) are also necessary for efficient nuclear egress of progeny nucleocapsids. Several baculovirus core or conserved proteins were found to interact with Vps4 and components of ESCRT-III, and these interactions may suggest the formation of an "egress complex" involved in the nuclear release or transport of viral nucleocapsids.

show abstract

Section: Isolation and Expression Of Escrt-i And Escrt-iii Componentsmentioning

confidence: 99%

Distinct Roles of Cellular ESCRT-I and ESCRT-III Proteins in Efficient Entry and Egress of Budded Virions of Autographa californica Multiple Nucleopolyhedrovirus

Yang

et al. 2018

J Virol

Self Cite

View full text Add to dashboard Cite

show abstract

“…AcMNPV was purified through a continuous 15-60% (w/v) sucrose gradient centrifugation. AcMNPV VP39-3×mCherry virus expressing both wild-type VP39 and VP39 fused to three copies of mCherry was generated as described previously (Biswas et al, 2016). The VP39-mCherry fusion construct was derived from the WOBCAT vector (Ohkawa et al, 2010).…”

Section: Virus Nucleocapsid and Cy3-nls-bsamentioning

confidence: 99%

A new mechanism for nuclear import by actin-based propulsion used by a baculovirus nucleocapsid

Zhou

et al. 2016

Journal of Cell Science

Self Cite

View full text Add to dashboard Cite

The transport of macromolecules into the nucleus is mediated by soluble cellular receptors of the importin β superfamily and requires the Ran-GTPase cycle. Several studies have provided evidence that there are exceptions to this canonical nuclear import pathway. Here, we report a new unconventional nuclear import mechanism exploited by the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV). We found that AcMNPV nucleocapsids entered the nucleus of digitonin-permeabilized cells in the absence of exogenous cytosol or under conditions that blocked the Ran-GTPase cycle. AcMNPV contains a protein that activates the Arp2/3 complex and induces actin polymerization at one end of the rod-shaped nucleocapsid. We show that inhibitors of Arp2/3 blocked nuclear import of nucleocapsids in semi-permeabilized cells. Nuclear import of nucleocapsids was also reconstituted in purified nuclei supplemented with G-actin and Arp2/3 under actin polymerization conditions. Thus, we propose that actin polymerization drives not only migration of baculovirus through the cytoplasm but also pushes the nucleocapsid through the nuclear pore complex to enter the cell nucleus. Our findings point to a very distinct role of actin-based motility during the baculovirus infection cycle.

show abstract

“…A recent study showed that VP39 interacts with a host kinesin 1 and that this interaction might be important for nucleocapsid transport (19). Although several VP39-interacting host and viral proteins have been identified (19)(20)(21), studies of VP39 itself are extremely limited, and to date, the functional domains or essential residues of this protein have not yet been identified.…”

mentioning

confidence: 99%

A Conserved Glycine Residue Is Required for Proper Functioning of a Baculovirus VP39 Protein

Katsuma

Kokusho

2017

J Virol

View full text Add to dashboard Cite

The baculovirus VP39 protein is a major nucleocapsid protein essential for viral propagation. However, the critical domains or residues of the VP39 protein have not yet been identified. Here, we performed mutagenesis experiments with Bombyx mori nucleopolyhedrovirus (BmNPV) using 5-bromo-2=-deoxyuridine and isolated a BmNPV mutant that produced fewer occlusion bodies than the wild-type virus. This mutant also produced fewer infectious budded viruses (BVs) than the wildtype virus in both cultured cells and B. mori larvae. Marker rescue experiments using genomic libraries identified a single nucleotide mutation in the vp39 gene. This mutation resulted in an amino acid substitution at glycine 276 (Gly-276) to serine, which was required for all the defective phenotypes observed in the mutant. Sequence comparison revealed that this residue is completely conserved among the VP39 proteins of the sequenced alphabaculoviruses, betabaculoviruses, and gammabaculoviruses. Although early viral gene expression was not significantly affected, the level of expression of a late gene, vcath, was reduced. In addition, two of the very late genes were markedly downregulated in cells infected with this mutant. Western blot and quantitative PCR analyses revealed that the BVs produced from cells infected with this mutant contained smaller amounts of the VP39 protein and viral genomic DNA than those produced from wild-type virus-infected cells. Combined with the results of transmission electron microscopy, VP39 Gly-276 can be concluded to be essential for correct nucleocapsid assembly, viral DNA packaging, and viral gene expression, especially of very late genes. IMPORTANCEThe major nucleocapsid protein gene vp39 is one of the most wellknown baculovirus genes. Although several viral and host proteins that interact with the VP39 protein have been identified, the functionally important domains or residues of this protein remain unknown. The present study revealed that the glycine residue at residue 276, which is completely conserved among sequenced alphabaculoviruses, betabaculoviruses, and gammabaculoviruses, is important for the VP39 function, i.e., structural assembly of nucleocapsids and viral DNA packaging. Moreover, our results provide evidence for the link between nucleocapsid formation and the transcription of viral very late genes.KEYWORDS baculovirus, nucleocapsid, BmNPV, VP39, few polyhedra T he Baculoviridae are a large family of viruses that infect insects, particularly those of the order Lepidoptera. Baculoviruses have a large circular, supercoiled, and doublestranded DNA genome packaged into rod-shaped virions (1, 2). They are divided into four genera, i.e., Alphabaculovirus, Betabaculovirus, Gammabaculovirus, and Deltabaculovirus (3). On the basis of molecular phylogenetic studies using genome sequences, alphabaculoviruses can be further subdivided into group I and II nucleopolyhedroviruses (NPVs) (4). NPVs produce two types of virions during their infection cycle.

show abstract

Trichoplusia ni Kinesin-1 Associates with Autographa californica Multiple Nucleopolyhedrovirus Nucleocapsid Proteins and Is Required for Production of Budded Virus

Cited by 14 publications

References 53 publications

Distinct Roles of Cellular ESCRT-I and ESCRT-III Proteins in Efficient Entry and Egress of Budded Virions of Autographa californica Multiple Nucleopolyhedrovirus

Distinct Roles of Cellular ESCRT-I and ESCRT-III Proteins in Efficient Entry and Egress of Budded Virions of Autographa californica Multiple Nucleopolyhedrovirus

A new mechanism for nuclear import by actin-based propulsion used by a baculovirus nucleocapsid

A Conserved Glycine Residue Is Required for Proper Functioning of a Baculovirus VP39 Protein

Contact Info

Product

Resources

About