Poxviral B1 kinase overcomes barrier to autointegration factor, a host defense against virus replication

Cell Host Microbe. 2007 May 17;1(3):187-97. doi: 10.1016/j.chom.2007.03.007.


Barrier to autointegration factor (BAF) is a DNA-binding protein found in the nucleus and cytoplasm of eukaryotic cells that functions to establish nuclear architecture during mitosis. Herein, we demonstrate a cytoplasmic role for BAF in host defense during poxviral infections. Vaccinia is the prototypic poxvirus, a family of DNA viruses that replicate exclusively in the cytoplasm of infected cells. Mutations in the vaccinia B1 kinase (B1) compromise viral DNA replication, but the mechanism by which B1 achieves this has remained elusive. We now show that BAF acts as a potent inhibitor of poxvirus replication unless its DNA-binding activity is blocked by B1-mediated phosphorylation. These data position BAF as the effector of an innate immune response that prevents replication of exogenous viral DNA in the cytoplasm. To enable the virus to evade this defense, the poxviral B1 has evolved to usurp a signaling pathway employed by the host cell.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Chlorocebus aethiops
  • DNA, Viral / biosynthesis
  • DNA-Binding Proteins / antagonists & inhibitors*
  • DNA-Binding Proteins / immunology
  • DNA-Binding Proteins / metabolism
  • Host-Pathogen Interactions / immunology*
  • Humans
  • Nuclear Proteins / antagonists & inhibitors*
  • Nuclear Proteins / immunology
  • Nuclear Proteins / metabolism
  • Phosphorylation
  • Vaccinia virus / enzymology*
  • Vaccinia virus / immunology*
  • Viral Proteins / genetics
  • Viral Proteins / metabolism*
  • Virus Replication / immunology*
  • Virus Replication / physiology


  • BANF1 protein, human
  • DNA, Viral
  • DNA-Binding Proteins
  • Nuclear Proteins
  • VB1R protein, Vaccinia virus
  • Viral Proteins