Bombyx mori nucleopolyhedrovirus ORF51 encodes a budded virus envelope associated protein

Abstract

Bombyx mori nucleopolyhedrovirus (BmNPV) ORF 51 (Bm51) is a gene present in many lepidopteran NPVs, but its function is unknown. In this study, Bm51 was characterized. Transcripts of Bm51 were detected from 4.5 through 72 hour post infection (h p.i.) by RT-PCR. The corresponding protein was detected from 6 to 72 h p.i. in BmNPV-infected BmN cells by western blot analysis using a polyclonal antibody against Bm51. Western blot assay of occlusion-derived virus and budded virus (BV) preparations revealed that Bm51 encodes a 23-kDa structural protein that is associated with BV and is located in the envelope fraction of budded virions. The protein was temporarily called BV-E23. In addition immunofluorescence microscopy demonstrated that the protein was present within the cytoplasm and nuclei in virus-infected cells. In conclusion, the available data suggest that Bm51 is a functional ORF of BmNPV and encodes a protein expressed in the early stage of the infection cycle that is associated with the BV envelope.

Genome-Wide Analysis of Host Responses to Four Different Types of Microorganisms inBombyx Mori(Lepidoptera: Bombycidae)

“…For example, when the Colorado potato beetle was infected by B. bassiana , there were significant linear relationships between larval weight gain, mortality, and sporulation. With regard to the timescale of BmNPV infection, expression of the Bm51 gene, encoding a 23-kDa structural protein located in the envelope fraction of the budded virion, was recently detected, both by RT-PCR and western blotting, from 6 to 72 hpi in BmNPV-infected BmN silkworm cells ( Tian et al. 2009 ).…”

Genome of Epinotia aporema granulovirus (EpapGV), a polyorganotropic fast killing betabaculovirus with a novel thymidylate kinase gene

“…Epap105 is similar to ac63 of Autographa californica MNPV (AcMNPV); their predicted proteins are 28% identical. Its homologue in Bombyx mori NPV (BmNPV), bm51 , was reported to be a structural gene associated with the budded virus (BV) envelope [27], but its deletion resulted in a virus with a phenotype similar to the wild type indicating that it might be a nonessential gene [28]. …”

Reduction of Baculovirus Replication in Insect Cells by Infection and/or Coinfection With a Recombinant Baculovirus Containing the Ns1 Protein of Influenza a Virus

“…The mechanism includes double-stranded RNA genome cleavage or intermediates, produced during replication, in short viral interference RNAs (siRNAs) [3,11,28]. The nonstructural protein 1 (NS1) of Influenza A virus has been related to the inhibition of the antiviral defense mediated by interferon, the regulation of viral translation and inhibition of host mRNA by RNAi suppression mechanisms and other cellular functions [2,15,18,23,25,26,27].…”

“…On the other hand, the NS1 protein could interfere with gene expression of the baculovirus itself which are important for viral replication, virus particle assembly and progeny virus formation. The interruption of the Open Reading Frame 41 (ORF41) of Bombyx mori NPV showed reduced of viral replication and affected the PIB formation [25]. NS1 protein could also be able to induce cell death in insect cells infected with vAcNS1.…”