Ectromelia virus BTB/kelch proteins, EVM150 and EVM167, interact with cullin-3-based ubiquitin ligases

Virology. 2008 Apr 25;374(1):82-99. doi: 10.1016/j.virol.2007.11.036. Epub 2008 Jan 24.

Abstract

Cellular proteins containing BTB and kelch domains have been shown to function as adapters for the recruitment of substrates to cullin-3-based ubiquitin ligases. Poxviruses are the only family of viruses known to encode multiple BTB/kelch proteins, suggesting that poxviruses may modulate the ubiquitin pathway through interaction with cullin-3. Ectromelia virus encodes four BTB/kelch proteins and one BTB-only protein. Here we demonstrate that two of the ectromelia virus-encoded BTB/kelch proteins, EVM150 and EVM167, interacted with cullin-3. Similar to cellular BTB proteins, the BTB domain of EVM150 and EVM167 was necessary and sufficient for cullin-3 interaction. During infection, EVM150 and EVM167 localized to discrete cytoplasmic regions, which co-localized with cullin-3. Furthermore, EVM150 and EVM167 co-localized and interacted with conjugated ubiquitin, as demonstrated by confocal microscopy and co-immunoprecipitation. Our findings suggest that the ectromelia virus-encoded BTB/kelch proteins, EVM150 and EVM167, interact with cullin-3 potentially functioning to recruit unidentified substrates for ubiquitination.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Artificial Gene Fusion
  • Cell Cycle Proteins / metabolism*
  • Cell Line
  • Cullin Proteins / metabolism*
  • Cytoplasm / chemistry
  • Ectromelia virus / genetics
  • Ectromelia virus / physiology*
  • Genes, Reporter
  • Green Fluorescent Proteins / biosynthesis
  • Green Fluorescent Proteins / genetics
  • Humans
  • Immunoprecipitation
  • Microscopy, Confocal
  • Models, Biological
  • Molecular Sequence Data
  • Protein Binding
  • Protein Interaction Domains and Motifs*
  • Protein Interaction Mapping*
  • Protein Structure, Tertiary
  • Sequence Alignment
  • Ubiquitin / metabolism
  • Viral Proteins / genetics
  • Viral Proteins / metabolism*

Substances

  • CUL3 protein, human
  • Cell Cycle Proteins
  • Cullin Proteins
  • Ubiquitin
  • Viral Proteins
  • Green Fluorescent Proteins