Proteomic analyses of baculovirus Anticarsia gemmatalis multiple nucleopolyhedrovirus budded and occluded virus

Abstract

Baculoviruses infect insects, producing two distinct phenotypes during the viral life cycle: the budded virus (BV) and the occlusion-derived virus (ODV) for intra-and inter-host spread, respectively. Since the 1980s, several countries have been using Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV) as a biological control agent against the velvet bean caterpillar, A. gemmatalis. The genome of AgMNPV isolate 2D (AgMNPV-2D) carries at least 152 potential genes, with 24 that possibly code for structural proteins. Proteomic studies have been carried out on a few baculoviruses, with six ODV and two BV proteomes completed so far. Moreover, there are limited data on virion proteins carried by AgMNPV-2D. Therefore, structural proteins of AgMNPV-2D were analysed by MALDI-quadrupole-TOF and liquid chromatography MS/MS. A total of 44 proteins were associated with the ODV and 33 with the BV of AgMNPV-2D. Although 38 structural proteins were already known, we found six new proteins in the ODV and seven new proteins carried by the AgMNPV-2D BV. Eleven cellular proteins that were found on several other enveloped viruses were also identified, which are possibly carried with the virion. These findings may provide novel insights into baculovirus biology and their host interaction. Moreover, our data may be helpful in subsequent applied studies aiming to improve AgMNPV use as a biopesticide and a biotechnology tool for gene expression or delivery. INTRODUCTIONTwo distinct phenotypes occur during the life cycle of baculoviruses: the budded virus (BV) responsible for intrahost systemic infection, and the occlusion-derived virus (ODV) that is essential for inter-host and oral primary infection in the environment (Keddie et al., 1989). At the end of the viral cycle, the ODV form is occluded in a paracrystalline protein matrix, which forms the occlusion bodies (OBs) (Blissard & Rohrmann, 1990;Castro et al., 1997;King & Possee, 1992). Members of the family Baculoviridae are insect-specific viruses and due to their high specificity have become widely used as biological control agents of pests in agriculture and forestry (Moscardi, 1999;O'Reilly et al., 1993;Szewczyk et al., 2006;Tanada & Kaya, 1993). In addition to their classical use as biopesticides, some baculoviruses are also used for recombinant protein production (Maeda, 1989;Smith et al., 1983), and more recently as vectors for human gene therapy (Airenne et al., 2013;Kost et al., 2005).Baculoviruses have a dsDNA genome contained in a rodshaped nucleocapsid, coding for 100-180 proteins (Herniou et al., 2003;Slack & Arif, 2007). Members of the family Baculoviridae are divided into two groups based on their OB morphology: nucleopolyhedrovirus (NPV) and granulovirus (GV). The lepidopteran NPVs are subdivided into groups I and II, following phylogenetic studies done with the polyhedrin gene (polh) (Zanotto et al., 1993), a larger set of conserved genes (Garavaglia et al., 2012;Herniou et al., 2003) or complete genomes (GarciaMaruniak et al., 2004;Lauzon et al., 2006;Olive...

Bombyx mori nucleopolyhedrovirus actin rearrangement-inducing factor 1 enhances systemic infection in B. mori larvae

“…AcMNPV ARIF-1 is colocalized with F-actin at the plasma membrane, but the loss of the C terminus in AcMNPV ARIF-1 abolishes their localization to the plasma membrane (Dreschers et al, 2001). ARIF-1 is not a component of BVs in AcMNPV (Dreschers et al, 2001), which is consistent with the results of proteomic studies on the BVs of AcMNPV and Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV) (Wang et al, 2010;Braconi et al, 2014). arif-1 disruption does not affect viral propagation in cultured cells (Dreschers et al, 2001;Taka et al, 2013) and the importance of ARIF-1-induced actin rearrangement in baculovirus infection is unknown.…”

Proteomic analysis of the occlusion-derived virus of Clostera anachoreta granulovirus

“…Furthermore, many different dephosphorylated forms of P6.9, as well as phosphorylated P6.9, were present in association with ODVs, although only dephosphorylated P6.9 was associated with BVs . P6.9 was also detected in the BV proteomes of HearNPV and AcMNPV, but not in the BV proteome of AgMNPV, which might be a result of P6.9 cleavage (Braconi et al, 2014;Liu et al, 2012). The biological significance of the cleavage of P6.9 remains unclear.…”

“…1). They covered 59.3 % of the complete theoretical proteome of ClanGV, which was a much higher percentage than those of other baculoviruses whose ODV compositions were successfully analysed by MS approaches (HearNPV, 42.2 %; CuniNPV, 41.3 %; PrGV, 39.2 %; ChchNPV, 35.1 %; AgMNPV, 28.9 %; AcMNPV, 28.6 %) (Braconi et al, 2014;Braunagel et al, 2003;Hou et al, 2013;Perera et al, 2007;Wang et al, 2011;Xu et al, 2011).…”

“…Our research showed that all PIFs were present in the ClanGV ODVs. Based solely on the results of MS, seven PIFs for PrGV, six for HearNPV, six for ChchNPV, five for AgMNPV and three for AcMNPV were identified as ODV proteins (Braconi et al, 2014;Braunagel et al, 2003;Hou et al, 2013;Wang et al, 2011;Xu et al, 2011). Moreover AcMNPV PIF-6 and HearNPV PIF-4 were shown to be ODV components by Western blotting.…”

“…These viruses include seven ODVs and three BVs: the ODVs of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) (Braunagel et al, 2003), Helicoverpa armigera nucleopolyhedrovirus (HearNPV) (Hou et al, 2013), Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV) (Braconi et al, 2014), Culex nigripalpus nucleopolyhedrovirus (CuniNPV) (Perera et al, 2007), Bombyx mori nucleopolyhedrovirus (BmNPV) (Liu et al, 2008), Chrysodeixis chalcites nucleopolyhedrovirus (ChchNPV) and Pieris rapae granulovirus (PrGV) (Wang et al, 2011); and the BVs of AcMNPV (Wang et al, 2010), HearNPV (Hou et al, 2013) and AgMNPV (Braconi et al, 2014). The numbers of proteins identified in these studies were 40,57,44,45,16,53,47,23,51 and 33, respectively.…”