title: Nuclear targeting activity associated with the amino terminal region of the Borna disease virus nucleoprotein.
abstract: The Borna disease virus (BDV) replicates in the nucleus. The viral p40 protein (N), which is found abundantly in the nucleus in BDV-infected cells, may play an important role in virus replication. To analyze the amino acid residues involved in the nuclear targeting of BDV N, a series of eukaryotic expression plasmids encoding deletion mutants of N was constructed and transfected into COS-7 cells. In indirect immunofluorescence assays with a rabbit anti-BDV N antiserum, wild-type N was located in the nucleus of transfected cells in the absence of other viral constituents. In contrast, mutants lacking the 13 NH2-terminal amino acid residues 1MPPKRRLVDDADA13 in common gave a cytoplasmic localization pattern. Similarly, a mutant with substitution of 4KRR6 by 4NSG6 was retained in the cytoplasm. Furthermore, a nonapeptide, 3PKRRLVDDA11, derived from the NH2-terminal region of N conferred nuclear targeting activity to beta-galactosidase, which normally resides in the cytoplasm. Thus, we have identified the nuclear targeting signal of the BDV N and narrowed it to the NH2-terminal region where 4KRR6 basic amino acid residues are located.
authors.affiliation: Institute of Immunological Science, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Shoya
authors.forename: T
authors.initials: T
authors.lastname: Koda
authors.forename: I
authors.initials: I
authors.lastname: Takashima
authors.forename: P K
authors.initials: PK
authors.lastname: Lai
authors.forename: K
authors.initials: K
authors.lastname: Ikuta
authors.forename: M
authors.initials: M
authors.lastname: Kakinuma
authors.forename: M
authors.initials: M
authors.lastname: Kishi
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000235:genetics; D001483:Base Sequence; D001891:Borna disease virus / Q000502:physiology*; D002467:Cell Nucleus / Q000821:virology; D015967:Gene Expression Regulation, Viral; D005814:Genes, Viral; D008969:Molecular Sequence Data; D010957:Plasmids; D011817:Rabbits; D017421:Sequence Analysis; D014764:Viral Proteins / Q000235:genetics*; D014779:Virus Replication / Q000235:genetics*
chemical_list: D000956:Antigens, Viral; D014764:Viral Proteins; C077347:p40 protein, Borna disease virus