Ectromelia virus encodes a BTB/kelch protein, EVM150, that inhibits NF-κB signaling

Qian Wang, Kristin Burles, Brianne Couturier, Crystal M H Randall, Joanna Shisler, Michele Barry

Research output: Contribution to journalArticlepeer-review


The NF-κB signaling pathway plays a critical role in inflammation and innate immunity. Consequently, many viruses have evolved strategies to inhibit NF-κB in order to facilitate replication and evasion of the host immune response. Recently, we determined that ectromelia virus, the causative agent of mousepox, contains a family of four BTB/kelch proteins that interact with cullin-3-based ubiquitin ligases. We demonstrate here that expression of EVM150, one of the four BTB/kelch proteins, inhibited NF-κB activation induced by tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β). Although EVM150 inhibited NF-κB p65 nuclear translocation, IκBα degradation was observed, indicating that EVM150 functioned downstream of IκBα degradation. Significantly, expression of the BTB-only domain of EVM150 blocked NF-κB activation, demonstrating that EVM150 functioned independently of the kelch domain and its role as an adapter for cullin-3-based ubiquitin ligases. Furthermore, cullin-3 knockdown by small interfering RNA demonstrated that cullin-3-based ubiquitin ligases are dispensable for TNF- α-induced NF-κB activation. Interestingly, nuclear translocation of IRF3 and STAT1 still occurred in the presence of EVM150, indicating that EVM150 prevented NF-κB nuclear translocation specifically. In addition to identifying EVM150 as an inhibitor of the NF-κB pathway, this study provides new insights into the role of BTB/kelch proteins during virus infection.

Original languageEnglish (US)
Pages (from-to)4853-4865
Number of pages13
JournalJournal of virology
Issue number9
StatePublished - May 2014

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Insect Science
  • Virology


Dive into the research topics of 'Ectromelia virus encodes a BTB/kelch protein, EVM150, that inhibits NF-κB signaling'. Together they form a unique fingerprint.

Cite this