Barrier to autointegration factor (BAF) inhibits vaccinia virus intermediate transcription in the absence of the viral B1 kinase

Authors

Nouhou Ibrahim, University of Nebraska–LincolnFollow
April Wicklund, University of Nebraska-LincolnFollow
Augusta Jamin, University of Nebraska–LincolnFollow
Matthew S. Wiebe, University of Nebraska-LincolnFollow

Date of this Version

9-2013

Citation

Published in Virology 444:1–2 (September 2013), pp. 363–373; doi: 10.1016/j.virol.2013.07.002

Comments

Copyright © 2013 Elsevier Inc. Used by permission.

Abstract

Barrier to autointegration factor (BAF/BANF1) is a cellular DNA-binding protein found in the nucleus and cytoplasm. Cytoplasmic BAF binds to foreign DNA and can act as a defense against vaccinia DNA replication. To evade BAF, vaccinia expresses the B1 kinase, which phosphorylates BAF and blocks its ability to bind DNA. Interestingly, B1 is also needed for viral intermediate gene expression via an unknown mechanism. Therefore, we evaluated the impact of B1-BAF signaling on vaccinia transcription. Strikingly, the decrease in vaccinia transcription caused by loss of B1 can be rescued by depletion of BAF. The repressive action of BAF is greatest on a viral promoter, and is more modest when non-vaccinia promoters are employed, which suggests BAF acts in a gene specific manner. These studies expand our understanding of the role of the B1 kinase during infection and provide the first evidence that BAF is a defense against viral gene expression.