title: Ectromelia virus BTB/kelch proteins, EVM150 and EVM167, interact with cullin-3-based ubiquitin ligases.
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.
authors.affiliation: Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Brianne A
authors.initials: BA
authors.lastname: Wilton
authors.forename: Stephanie
authors.initials: S
authors.lastname: Campbell
authors.forename: Nicholas
authors.initials: N
authors.lastname: Van Buuren
authors.forename: Robyn
authors.initials: R
authors.lastname: Garneau
authors.forename: Manabu
authors.initials: M
authors.lastname: Furukawa
authors.forename: Yue
authors.initials: Y
authors.lastname: Xiong
authors.forename: Michele
authors.initials: M
authors.lastname: Barry
mesh_terms: D000595:Amino Acid Sequence; D019677:Artificial Gene Fusion; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002460:Cell Line; D044842:Cullin Proteins / Q000378:metabolism*; D003593:Cytoplasm / Q000737:chemistry; D004481:Ectromelia virus / Q000235:genetics / Q000502:physiology*; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D047468:Immunoprecipitation; D018613:Microscopy, Confocal; D008954:Models, Biological; D008969:Molecular Sequence Data; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D025801:Ubiquitin / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C503645:CUL3 protein, human; D018797:Cell Cycle Proteins; D044842:Cullin Proteins; D025801:Ubiquitin; D014764:Viral Proteins; D049452:Green Fluorescent Proteins