The Heliothis armigera single nucleocapsid nucleopolyhedrovirus envelope protein P74 is required for infection of the host midgut

Yao, Lunguang; Zhou, Wenke; Xu, Hua; Zheng, Yong; Qi, Yipeng

doi:10.1016/j.virusres.2004.03.005

Cited by 39 publications

(45 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Two studies (Haas-Stapleton et al, 2004;Yao et al, 2004) have concluded that P74 is a viral attachment protein. Haas-Stapleton et al (2004) …”

Section: Discussionmentioning

confidence: 99%

“…Two studies (Haas-Stapleton et al, 2004;Yao et al, 2004) have concluded that P74 is a viral attachment protein. Haas-Stapleton et al (2004) showed that the P74D virus could not compete with wt virus ODVs for binding to the midgut and Yao et al (2004) identified a 30 kDa midgut receptor protein for P74.…”

Section: Discussionmentioning

confidence: 99%

“…It has been established that a P74 fused with the green fluorescent protein can function in place of native P74 (Yao et al, 2004). In this assay, insect cells were co-transfected with P74 null virus DNA and a plasmid expressing the p74 gene fused in-frame with the enhanced green fluorescent protein (egfp) gene.…”

Section: Introductionmentioning

confidence: 99%

“…A number of ODV envelope proteins are essential per os infectivity factors (PIFs), including P74 , PIF1 (Kikhno et al, 2002), PIF2 (Pijlman et al, 2003 and PIF3 (Ohkawa et al, 2005). PIF1, PIF2 and P74 have been implicated to be involved in ODV attachment to midgut cells (Haas-Stapleton et al, 2004;Yao et al, 2004;Ohkawa et al, 2005). P74, the first identified PIF , is Nterminally exposed on the ODV surface and C-terminally anchored in the ODV envelope (Faulkner et al, 1997;Rashidan et al, 2005).…”

mentioning

confidence: 99%

“…There was insufficient material for Nterminal sequencing of BBMV-specific P74-EGFP cleavage products, but the molecular masses of the products correspond well with cleavage in the R195/R196/R199 region. This is supported by lack of a specific cleavage product in the R195Q/R196Q/R199Q mutant.Two studies (Haas-Stapleton et al, 2004;Yao et al, 2004) have concluded that P74 is a viral attachment protein. Haas-Stapleton et al (2004) …”

mentioning

confidence: 99%

See 4 more Smart Citations

Trypsin cleavage of the baculovirus occlusion-derived virus attachment protein P74 is prerequisite in per os infection

Slack

Lawrence²,

Krell

et al. 2008

Journal of General Virology

View full text Add to dashboard Cite

Baculovirus occlusion-derived virions (ODVs) contain a number of infectivity factors essential for the initiation of infection in larval midgut cells. Deletion of any of these factors neutralizes infectivity by the per os route. We have observed that P74 of the group I alphabaculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is N-terminally cleaved when a soluble form of the protein was incubated with insect midgut tissues under alkaline conditions and that cleavage was prevented by soybean trypsin inhibitor (SBTI). Presently, biological assays were carried out that suggest SBTI inhibits and trypsin enhances baculovirus per os infectivity. We developed a method to rescue per os infectivity of a P74 null virus involving co-transfection of viral DNA with a plasmid that transiently expresses p74. We used this plasmid rescue method to functionally characterize P74. A series of site-directed mutants were generated at the N terminus to evaluate if trypsin cleavage sites were necessary for function. Mutagenesis of R195, R196 and R199 compromised per os infectivity and rendered P74 resistant to midgut trypsin. INTRODUCTIONBaculoviruses are a group of arthropod-specific viruses (Zanotto et al., 1993) that have been applied as insecticides and as vectors for the expression of exogenous genes. They have a biphasic replication strategy producing two distinct viral phenotypes: the budded virion (BV) and the occlusion-derived virion (ODV). Both virion phenotypes have bilayer lipid envelopes surrounding bacillus-shaped nucleocapsids and contain double-stranded, circular DNA genomes. However, the integral protein composition of their envelopes and their roles in infection are distinct.BVs spread viral infection throughout host tissues by attaching to and entering host cells via receptor-mediated endocytosis (Volkman & Goldsmith, 1985). Endosomal acidification triggers envelope fusion with the endosomal membrane to release the viral nucleocapsid into the host cell (Leikina et al., 1992). In the case of group I alphabaculoviruses (Jehle et al., 2006), budding, attachment and envelope fusion are mediated by the viral protein GP64 (Blissard & Wenz, 1992) and for other baculovirus types these processes are mediated by an F protein (Pearson et al., 2000; Westenberg et al., 2002).ODVs are required in the horizontal transmission of baculoviruses between insect hosts (Kozlov et al., 1986). The ODVs of all baculoviruses are occluded into proteinaceous occlusion bodies (OBs) prior to release from the host (Rohrmann, 1986). The distinctive protein structure of OBs has a dual function. It serves to protect virions from deleterious environmental factors, and also acts as a delivery mechanism to transport the ODVs to the alkaline midgut where the cells are susceptible to infection.ODV envelopes are derived from the inner nuclear membrane (Braunagel & Summers, 1994) and contain envelope proteins that can survive the protease-rich environment of the insect midgut. ODVs attach to midgut columnar epithelial cells and fuse th...

show abstract

“…Two studies (Haas-Stapleton et al, 2004;Yao et al, 2004) have concluded that P74 is a viral attachment protein. Haas-Stapleton et al (2004) …”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Trypsin cleavage of the baculovirus occlusion-derived virus attachment protein P74 is prerequisite in per os infection

Slack

Lawrence²,

Krell

et al. 2008

Journal of General Virology

View full text Add to dashboard Cite

show abstract

Host Filamentous Actin Is Associated with Heliothis armigera Single Nucleopolyhedrosis Virus (HaSNPV) Nucleocapsid Transport to the Host Nucleus

Yao²,

et al. 2007

Curr Microbiol

View full text Add to dashboard Cite

VP39 is the major capsid protein of Heliothis armigera nucleopolyhedrovirus (HaSNPV), and it might have induced the aggregation of host cellular actin in vitro in our previous study. We demonstrated here that VP39 could interact with host actin in vivo in Helicoverpazea (Hz-AM1 cells) through coimmunoprecipitation assay. With confocal immunofluorescence microscopy, it was confirmed further that the released HaSNPV nucleocapsids/VP39s in the host cytoplasm (0.5 hours after infection) colocalized where the actin aggregated and that the nucleocapsids/VP39s were transported from the host cytoplasm to the nucleus (2 hours after infection). Because cytochalasin D (CD) was used to prevent host global actin from forming filamentous structures, the infection efficiency of the recombinant virus HaSNPV/gfpdeltap74, with the gfp gene inserted into HaSNPV p74 gene loci, was decreased to 7.34%, whereas it was 34.7% in normal host cells and 55.7% in the cells whose microtubules had been destroyed by colchicin. Ultramicroscopy assay revealed that HaSNPV nucleocapsids could enter the cytoplasm of CD-treated cells but could not be transported to the nucleus, which resulted in the lower infection efficiency of HaSNPV/gfpdeltap74 in CD-treated cells. However, transportation of the nucleocapsids was not inhibited in colchicin-treated cells, demonstrating that the transportation of HaSNPV nucleocapsid from the cytoplasm to the nucleus was associated with actin filaments but not with microtubules, a conclusion that is also strongly supported by evidence from the RNAi interference of host actin during HaSNPV infection.

show abstract

Sequencing and Characterisation of p74 Gene in Two Isolates of Anticarsia Gemmatalis MNPV

et al. 2006

View full text Add to dashboard Cite

P74 is a protein encoded in the genome of baculoviruses, associated with the envelopes of occluded virus. Its presence proved to be essential for per os infection. In first place, in this work we designed two universal primers to amplify a sequence region of the p74 ORF in baculoviruses from different classification groups. Then, by the use of these amplicons we obtained the complete sequence of the p74 locus from two isolates of AgMNPV, 2D (Brazil) and SF (Argentina). In the flanking regions we determined the complete sequence of p10 gene and a portion of p26 gene. Comparing both p74 sequence data (ORFs of 1935 bp) we found fifteen nucleotide changes that result in six amino acid changes. Comparisons of AgMNPV p74s with other baculovirus homologous genes indicate a close relationship with other group I Nucleopolyhedrovirus, in particular CfDEFNPV. These results were based on ORF sequence, amino acid sequence and gene order. The predictive studies about secondary structure and hydrophobic index point at six regions potentially associated to its function or native conformation. Finally, the detection of p74 mRNA after virus DNA replication confirms a late expression pattern.

show abstract

The Heliothis armigera single nucleocapsid nucleopolyhedrovirus envelope protein P74 is required for infection of the host midgut

Cited by 39 publications

References 30 publications

Trypsin cleavage of the baculovirus occlusion-derived virus attachment protein P74 is prerequisite in per os infection

Trypsin cleavage of the baculovirus occlusion-derived virus attachment protein P74 is prerequisite in per os infection

Host Filamentous Actin Is Associated with Heliothis armigera Single Nucleopolyhedrosis Virus (HaSNPV) Nucleocapsid Transport to the Host Nucleus

Sequencing and Characterisation of p74 Gene in Two Isolates of Anticarsia Gemmatalis MNPV

Contact Info

Product

Resources

About