After ingestion of occlusion bodies, the occlusion-derived viruses (ODVs) of the baculoviruses establish the first round of infection within the larval host midgut cells. Several ODV envelope proteins, called per os infectivity factors (PIFs), have been shown to be essential for oral infection. Eight PIFs have been identified to date, including P74, PIFs 1–6 and Ac110. At least six PIFs, P74, PIFs 1–4 and PIF6, together with three other ODV-specific proteins, Ac5, P95 (Ac83) and Ac108, have been reported to form a complex on the ODV surface. In this study, in order to understand the interactions of these PIFs, the direct protein–protein interactions of the nine components of the Autographa californica multiple nucleopolyhedrovirus PIF complex were investigated using yeast two-hybrid (Y2H) screening combined with bimolecular fluorescence complementation (BiFC) assay. Six direct interactions, comprising PIF1–PIF2, PIF1–PIF3, PIF1–PIF4, PIF1–P95, PIF2–PIF3 and PIF3–PIF4, were identified in the Y2H analysis, and these results were further verified by BiFC. For P74, PIF6, Ac5 and Ac108, no direct interaction was identified. P95 (Ac83) was identified to interact with PIF1, and further Y2H analysis of the truncation and deletion mutants showed that the predicted P95 chitin-binding domain and amino acids 100–200 of PIF1 were responsible for P95 interaction with PIF1. Furthermore, a summary of the protein–protein interactions of PIFs reported so far, comprising 10 reciprocal interactions and two self-interactions, is presented, which will facilitate our understanding of the characteristics of the PIF complex.
HerniouEA,
OlszewskiJA,
CoryJS,
O'ReillyDR.
The genome sequence and evolution of baculoviruses. Annu Rev Entomol2003; 48:211–234 [View Article][PubMed]
JehleJA,
BlissardGW,
BonningBC,
CoryJS,
HerniouEA et al. On the classification and nomenclature of baculoviruses: a proposal for revision. Arch Virol2006; 151:1257–1266 [View Article][PubMed]
KozlovEA,
LevitinaTL,
GusakNM.
The primary structure of baculovirus inclusion body proteins. Evolution and structure-function aspects. Curr Top Microbiol Immunol1986; 131:135–164[PubMed]
HortonHM,
BurandJP.
Saturable attachment sites for polyhedron-derived baculovirus on insect cells and evidence for entry via direct membrane fusion. J Virol1993; 67:1860–1868[PubMed]
KawanishiCY,
SummersMD,
StoltzDB,
ArnottHJ.
Entry of an insect virus in vivo by fusion of viral envelope and microvillus membrane. J Invertebr Pathol1972; 20:104–108 [View Article][PubMed]
TanadaY,
HessRT,
OmiEM.
Invasion of a nuclear polyhedrosis virus in midgut of the armyworm, Pseudaletia unipuncta, and the enhancement of a synergistic enzyme. J Invertebr Pathol1975; 26:99–104 [View Article][PubMed]
KuzioJ,
JaquesR,
FaulknerP.
Identification of p74, a gene essential for virulence of baculovirus occlusion bodies. Virology1989; 173:759–763 [View Article][PubMed]
FaulknerP,
KuzioJ,
WilliamsGV,
WilsonJA.
Analysis of p74, a PDV envelope protein of Autographa californica nucleopolyhedrovirus required for occlusion body infectivity in vivo
. J Gen Virol1997; 78:3091–3100 [View Article][PubMed]
KikhnoI,
GutiérrezS,
CroizierL,
CroizierG,
FerberML.
Characterization of pif, a gene required for the per os infectivity of Spodoptera littoralis nucleopolyhedrovirus. J Gen Virol2002; 83:3013–3022 [View Article][PubMed]
PijlmanGP,
PruijssersAJ,
VlakJM.
Identification of pif-2, a third conserved baculovirus gene required for per os infection of insects. J Gen Virol2003; 84:2041–2049 [View Article][PubMed]
OhkawaT,
WashburnJO,
SitaparaR,
SidE,
VolkmanLE.
Specific binding of Autographa californica M nucleopolyhedrovirus occlusion-derived virus to midgut cells of Heliothis virescens larvae is mediated by products of pif genes Ac119 and Ac022 but not by Ac115
. J Virol2005; 79:15258–15264 [View Article][PubMed]
SparksWO,
HarrisonRL,
BonningBC.
Autographa californica multiple nucleopolyhedrovirus ODV-E56 is a per os infectivity factor, but is not essential for binding and fusion of occlusion-derived virus to the host midgut. Virology2011; 409:69–76 [View Article][PubMed]
NieY,
FangM,
ErlandsonMA,
TheilmannDA.
Analysis of the Autographa californica multiple nucleopolyhedrovirus overlapping gene pair lef3 and ac68 reveals that AC68 is a per os infectivity factor and that LEF3 is critical, but not essential, for virus replication. J Virol2012; 86:3985–3994 [View Article][PubMed]
LiuJ,
ZhuL,
ZhangS,
DengZ,
HuangZ et al. The Autographa californica multiple nucleopolyhedrovirus ac110 gene encodes a new per os infectivity factor. Virus Res 221:30–37 [View Article][PubMed]
Haas-StapletonEJ,
WashburnJO,
VolkmanLE.
P74 mediates specific binding of Autographa californica M nucleopolyhedrovirus occlusion-derived virus to primary cellular targets in the midgut epithelia of Heliothis virescens larvae. J Virol2004; 78:6786–6791 [View Article][PubMed]
MuJ,
van LentJW,
SmaggheG,
WangY,
ChenX et al. Live imaging of baculovirus infection of midgut epithelium cells: a functional assay of per os infectivity factors. J Gen Virol2014; 95:2531–2539 [View Article][PubMed]
YaoL,
ZhouW,
XuH,
ZhengY,
QiY.
The Heliothis armigera single nucleocapsid nucleopolyhedrovirus envelope protein P74 is required for infection of the host midgut. Virus Res2004; 104:111–121 [View Article][PubMed]
ZhouW,
YaoL,
XuH,
YanF,
QiY.
The function of envelope protein P74 from Autographa californica multiple nucleopolyhedrovirus in primary infection to host. Virus Genes2005; 30:139–150 [View Article][PubMed]
PengK,
van LentJW,
BoerenS,
FangM,
TheilmannDA et al. Characterization of novel components of the baculovirus per os infectivity factor complex. J Virol2012; 86:4981–4988 [View Article][PubMed]
PengK,
van OersMM,
HuZ,
van LentJW,
VlakJM.
Baculovirus per os infectivity factors form a complex on the surface of occlusion-derived virus. J Virol2010; 84:9497–9504 [View Article][PubMed]
FanJY,
CuiZQ,
WeiHP,
ZhangZP,
ZhouYF et al. Split mCherry as a new red bimolecular fluorescence complementation system for visualizing protein-protein interactions in living cells. Biochem Biophys Res Commun2008; 367:47–53 [View Article][PubMed]
ZhuS,
WangW,
WangY,
YuanM,
YangK.
The baculovirus core gene ac83 is required for nucleocapsid assembly and per os infectivity of Autographa californica nucleopolyhedrovirus. J Virol2013; 87:10573–10586 [View Article][PubMed]
PengK,
WuM,
DengF,
SongJ,
DongC et al. Identification of protein-protein interactions of the occlusion-derived virus-associated proteins of Helicoverpa armigera nucleopolyhedrovirus. J Gen Virol2010; 91:659–670 [View Article][PubMed]
SongJ,
WangR,
DengF,
WangH,
HuZ.
Functional studies of per os infectivity factors of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus. J Gen Virol2008; 89:2331–2338 [View Article][PubMed]
PengK,
van LentJW,
VlakJM,
HuZ,
van OersMM.
In situ cleavage of baculovirus occlusion-derived virus receptor binding protein P74 in the peroral infectivity complex. J Virol2011; 85:10710–10718 [View Article][PubMed]
ElorzaMV,
RicoH,
SentandreuR.
Calcofluor white alters the assembly of chitin fibrils in Saccharomyces cerevisiae and Candida albicans cells. Microbiology1983; 129:1577–1582 [View Article]
LiZ,
LiC,
YangK,
WangL,
YinC et al. Characterization of a chitin-binding protein GP37 of Spodoptera litura multicapsid nucleopolyhedrovirus. Virus Res2003; 96:113–122[PubMed][Crossref]