Nuclear targeting activity associated with the amino terminal region of the Borna disease virus nucleoprotein

Virology. 1998 Mar 30;243(1):188-97. doi: 10.1006/viro.1998.9049.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Viral / genetics
  • Base Sequence
  • Borna disease virus / physiology*
  • Cell Nucleus / virology
  • Gene Expression Regulation, Viral*
  • Genes, Viral
  • Molecular Sequence Data
  • Plasmids
  • Rabbits
  • Sequence Analysis
  • Viral Proteins / genetics*
  • Virus Replication / genetics*


  • Antigens, Viral
  • Viral Proteins
  • p40 protein, Borna disease virus