Protein composition analysis of polyhedra matrix of Bombyx mori nucleopolyhedrovirus (BmNPV) showed powerful capacity of polyhedra to encapsulate foreign proteins

Abstract

Polyhedra can encapsulate other proteins and have potential applications as protein stabilizers. The extremely stable polyhedra matrix may provide a platform for future engineered micro-crystal devices. However, the protein composition of the polyhedra matrix remains largely unknown. In this study, the occlusion-derived virus (ODV)-removed BmNPV polyhedra matrix fraction was subjected to SDS-PAGE and then an LC-ESI-MS/MS analysis using a Thermo Scientific Q Exactive mass spectrometer. In total, 28 host and 91 viral proteins were identified. The host components were grouped into one of six categories, i.e., chaperones, ubiquitin and related proteins, host helicases, cytoskeleton-related proteins, RNA-binding proteins and others, according to their predicted Pfam domain(s). Most viral proteins may not be essential for polyhedra assembly, as evidenced by studies in the literature showing that polyhedra formation occurs in the nucleus upon the disruption of individual genes. The structural role of these proteins in baculovirus replication will be of significant interest in future studies. The immobilization of enhanced green fluorescent protein (eGFP) into the polyhedra by fusing with the C-terminus of BM134 that is encoded by open reading frame (ORF) 134 suggested that the polyhedra had a powerful capacity to trap foreign proteins, and BM134 was a potential carrier for incorporating proteins of interest into the polyhedra.

Involvement of the neddylation modification system in Bombyx mori nucleopolyhedrovirus replication

“…It was also shown that OBs could not be formed by fusing proteins to polyhedrin, except in the presence of wild‐type virus (Sampieri et al, 2015). We detected 28 host proteins and 91 viral proteins embedded inside BmNPV OBs (Guo et al, 2017). These results indicate that the assembly of OBs is a complicated and well‐regulated process.…”

“…The autophagosome was labeled mCherry fused with marker BmLC3 pathogenesis (Furlong & Hwang, 2019;Ke, 2018). It has been reported BmNPV infection induced autophagy in host cells (Wang et al, 2017). Polyhedrin directly interacts with LC3, and inhibition of autophagy by 3-methyladenine (3-MA) decreased polyhedrin expression and OB production (Guo et al, 2015).…”

Baculovirus as Versatile Vectors for Protein Display and Biotechnological Applications

“…The N-terminal 50 amino acids of polyhedrin represents the recognition signal necessary for foreign protein incorporation, and the N-terminal 100 amino acids of polyhedrin allowed for the most efficient protein incorporation into polyhedral occlusion bodies . The protein encoded by ORF 134 of BmNPV has also been shown to be a suitable fusion partner for OBD (Guo et al, 2017).…”

Baculovirus as Versatile Vectors for Protein Display and Biotechnological Applications

“…The N-terminal 50 amino acids of polyhedrin represents the recognition signal necessary for foreign protein incorporation, and the N-terminal 100 amino acids of polyhedrin allowed for the most efficient protein incorporation into polyhedral occlusion bodies (Chen et al, 2013). The protein encoded by ORF 134 of BmNPV has also been shown to be a suitable fusion partner for OBD (Guo et al, 2017).…”