title: Bombyx mori nucleopolyhedrovirus nucleic acid binding proteins BRO-B and BRO-E associate with host T-cell intracellular antigen 1 homologue BmTRN-1 to influence protein synthesis during infection.
abstract: Previous reports have indicated that the Bombyx mori nucleopolyhedrovirus (BmNPV) nucleic acid binding proteins BRO-B and BRO-E are expressed during the early stage of infection and that the BRO family likely supports the regulation of mRNA; however, no study has directly examined the function of BRO family proteins in virus-permissive cells. Here, we show that BRO-B and BRO-E associate with cellular T-cell intracellular antigen 1 homologue (BmTRN-1), a translational regulator, and other cellular translation-related proteins in silkworm cells during viral infection. We created BM-N cells that expressed BRO-B/E to study molecular interactions between BmTRN-1 and BRO-B/E and how they influenced protein synthesis. Fluorescent microscopy revealed that BmTRN-1 was localized in cytoplasmic foci during BmNPV infection. Immunofluorescence studies confirmed that BmTRN-1 and BRO-B/E were colocalized in the amorphous conspicuous cytoplasmic foci. Reporter gene studies revealed that co-expression of BRO-B/E synergistically led to a significant decrease in protein synthesis from a designed transcript carrying the 5'untranslated region of a cellular mRNA with no significant change of transcript abundance. Additionally, RNA interference-mediated knockdown of BmTRN-1 resulted in a marked inhibition of the ability of BRO-B/E to regulate the transcript. These results suggested that the association of BmTRN-1 with BRO-B/E is responsible for the inhibitory regulation of certain mRNAs at the post-transcriptional level and add an additional mechanism for how baculoviruses control protein synthesis during infection.
authors.affiliation: 1Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan 2Insect Biomedical Center, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Kotani
authors.affiliation: 1Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Muto
authors.affiliation: 2Insect Biomedical Center, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ijiri
authors.affiliation: 1Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan 2Insect Biomedical Center, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Mori
mesh_terms: D000818:Animals; D012831:Bombyx / Q000821:virology*; D015967:Gene Expression Regulation, Viral; D054884:Host-Pathogen Interactions; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D017924:Nucleopolyhedroviruses / Q000502:physiology*; D011485:Protein Binding; D014176:Protein Biosynthesis; D025941:Protein Interaction Mapping; D016601:RNA-Binding Proteins / Q000378:metabolism*; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D016601:RNA-Binding Proteins; D014764:Viral Proteins