title: Adenovirus E4-ORF3-dependent relocalization of TIF1α and TIF1γ relies on access to the Coiled-Coil motif.
abstract: The adenovirus E4-ORF3 protein promotes viral replication by relocalizing cellular proteins into nuclear track structures, interfering with potential anti-viral activities. E4-ORF3 targets transcriptional intermediary factor 1 alpha (TIF1α), but not homologous TIF1β. Here, we introduce TIF1γ as a novel E4-ORF3-interacting partner. E4-ORF3 relocalizes endogenous TIF1γ in virus-infected cells in vivo and binds to TIF1γ in vitro. We used the homologous nature, yet differing binding capabilities, of these proteins to study how E4-ORF3 targets proteins for track localization. We mapped the ability of E4-ORF3 to interact with specific TIF1 subdomains, demonstrating that E4-ORF3 interacts with the Coiled-Coil domains of TIF1α, TIF1β, and TIF1γ, and that the C-terminal half of TIF1β interferes with this interaction. The results of E4-ORF3-directed TIF1 protein relocalization assays performed in vivo were verified using coimmunoprecipitation assays in vitro. These results suggest that E4-ORF3 targets proteins for relocalization through a loosely homologous sequence dependent on accessibility.
authors: Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA.
authors: Elizabeth I
authors: EI
authors: Vink
authors: Mark A
authors: MA
authors: Yondola
authors: Kai
authors: K
authors: Wu
authors: Patrick
authors: P
authors: Hearing
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D051958:Nuclear Receptor Coactivator 2 / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: C498001:NCOA2 protein, human; D009687:Nuclear Proteins; D051958:Nuclear Receptor Coactivator 2; D014157:Transcription Factors; C093517:transcriptional intermediary factor 1